Anemia

ATLANTA – Virtual clinic visits have enabled sickle cell disease patients to stay alive and healthier during the COVID-19 pandemic, but concerns remain for those who lack access to specialized care centers, according to an investigator at the annual meeting of the American Society of Hematology.

During the first COVID-19 wave in the summer of 2020, Atlanta’s Grady Sickle Cell Center, the nation’s largest adult sickle cell center, recorded two deaths among the 20 COVID-19_infected patients seen there, said Fuad El Rassi, MD, of Emory University, Atlanta.

ASH

ATLANTA – Virtual clinic visits have enabled sickle cell disease patients to stay alive and healthier during the COVID-19 pandemic, but concerns remain for those who lack access to specialized care centers, according to an investigator at the annual meeting of the American Society of Hematology.

During the first COVID-19 wave in the summer of 2020, Atlanta’s Grady Sickle Cell Center, the nation’s largest adult sickle cell center, recorded two deaths among the 20 COVID-19_infected patients seen there, said Fuad El Rassi, MD, of Emory University, Atlanta.

ASH

ATLANTA – Virtual clinic visits have enabled sickle cell disease patients to stay alive and healthier during the COVID-19 pandemic, but concerns remain for those who lack access to specialized care centers, according to an investigator at the annual meeting of the American Society of Hematology.

During the first COVID-19 wave in the summer of 2020, Atlanta’s Grady Sickle Cell Center, the nation’s largest adult sickle cell center, recorded two deaths among the 20 COVID-19_infected patients seen there, said Fuad El Rassi, MD, of Emory University, Atlanta.

ASH

In patients with transfusion-dependent beta-thalassemia, a single gene therapy infusion is capable of yielding durable transfusion independence and substantial improvements in iron overload, an investigator reported at the annual meeting of the American Society of Hematology.

Among patients who received betibeglogene autotemcel (beti-cel) in a phase 3 trial and enrolled in a long-term follow-up study, nearly 90% achieved durable transfusion independence, according to Alexis A. Thompson, MD, MPH, of the hematology section at the Ann & Robert H. Lurie Children’s Hospital of Chicago.

The median duration of ongoing transfusion independence was nearly 3 years as of this report, which Dr. Thompson described in a press conference at the meeting.

In a subanalysis of this international study, Dr. Thompson and co-investigators reported that in patients who achieve transfusion independence, chelation reduced iron, and iron markers stabilized even after chelation was stopped.

Beyond 2 years post-infusion, no adverse events related to the drug product were seen. This suggested that the therapy has a favorable long-term safety profile, according to Dr. Thompson.

“At this point, we believe that beti-cel is potentially curative for patients with TDT [transfusion-dependent beta-thalassemia],” Dr. Thompson said in the press conference.

This study answers one of the major outstanding questions about beti-cel and iron metabolism, according to Arielle L. Langer, MD, MPH, an instructor in medicine at Harvard Medical School and attending physician for adult thalassemia patients at Brigham and Women’s and Dana Farber Cancer Institute, both in Boston.

“Seeing the restoration of iron metabolism, it really takes us a step closer to really thinking the term ‘cure’ might truly apply,” Dr. Langer said in an interview.

Dr. Langer said she looks forward to “very long-term outcomes” of beti-cel-treated patients to see whether endocrinopathies and other long-term sequelae of TDT are also abated.

“This [study] is a great intermediate point, but really, when we think about how thalassemia harms and kills our patients, we really sometimes measure that in decades,” she said.

Beta-thalassemia is caused by mutations in the beta-globin gene, resulting in reduced levels of hemoglobin. Patients with TDT, the most serious form of the disease, have severe anemia and are often dependent on red blood cell transfusions from infancy onward, Dr. Thompson said.

With chronic transfusions needed to maintain hemoglobin levels, TDT patients inevitably experience iron overload, which can lead to organ damage and can be fatal. Consequently, patients will require lifelong iron chelation therapy, she added.

Beti-cel, an investigational ex vivo gene addition therapy currently under review by the U.S. Food and Drug Administration, involves adding functional copies of a modified form of the beta-globin gene into a patient’s own hematopoietic stem cells. Once those cells are reinfused, patients may produce adult hemoglobin at levels that eliminate the need for transfusions, according to Dr. Thompson.

At the meeting, Dr. Thompson reported on patients from two phase 1/2 and two phase 3 beti-cel clinical trials who subsequently enrolled in LTF-303, a 13-year follow-up study of the gene therapy’s safety and efficacy.

A total of 57 patients were included in this report, making it the largest gene therapy program to date in any blood disorder, according to Dr. Thompson. Before receiving beti-cel, the patients, who had a broad range of thalassemia genotypes, were receiving between 10 and almost 40 red blood cell transfusions per year, she reported.

Patients ranged in age from 5 to 35 years. The median age in the phase 1/2 studies was 20 years, while in the phase 3 studies it was 15 years.

“The early experience in the phase 1/2 trials allowed us to be more comfortable with enrolling more children, and that has actually helped us to understand safety and efficacy and children in the phase 3 setting,” Dr. Thompson said.

Fertility preservation measures had been undertaken by about 59% of patients from the phase 1/2 studies and 71% of patients from the phase 3 studies, the data show.

Among patients from the phase 3 beti-cel studies who could be evaluated, 31 out of 35 (or 89%) achieved durable transfusion independence, according to the investigator.

The median duration of ongoing transfusion independence was 32 months, with a range of about 18 to 49 months, she added.

Dr. Thompson also reported a subanalysis intended to assess iron status in 16 patients who restarted and then stopped chelation. That subanalysis demonstrated iron reduction in response to chelation, and then stabilization of iron markers after chelation was stopped. Post-gene therapy chelation led to reductions in liver iron concentration and serum ferritin that remained relatively stable after chelation was stopped, she said.

Serious adverse events occurred in eight patients in the long-term follow-up study. However, adverse events related to beti-cel have been absent beyond 2 years post-infusion, according to Dr. Thompson, who added that there have been no reported cases of replication-competent lentivirus, no clonal expansion, no insertional oncogenesis, and no malignancies observed.

“Very reassuringly, there have been 2 male patients, one of whom underwent fertility preservation, who report having healthy children with their partners,” she added.

Dr. Thompson provided disclosures related to Baxalta, Biomarin, bluebird bio, Inc., Celgene/BMS, CRISPR Therapeutics, Vertex, Editas, Graphite Bio, Novartis, Agios, Beam, and Global Blood Therapeutics.
 

In patients with transfusion-dependent beta-thalassemia, a single gene therapy infusion is capable of yielding durable transfusion independence and substantial improvements in iron overload, an investigator reported at the annual meeting of the American Society of Hematology.

Among patients who received betibeglogene autotemcel (beti-cel) in a phase 3 trial and enrolled in a long-term follow-up study, nearly 90% achieved durable transfusion independence, according to Alexis A. Thompson, MD, MPH, of the hematology section at the Ann & Robert H. Lurie Children’s Hospital of Chicago.

The median duration of ongoing transfusion independence was nearly 3 years as of this report, which Dr. Thompson described in a press conference at the meeting.

In a subanalysis of this international study, Dr. Thompson and co-investigators reported that in patients who achieve transfusion independence, chelation reduced iron, and iron markers stabilized even after chelation was stopped.

Beyond 2 years post-infusion, no adverse events related to the drug product were seen. This suggested that the therapy has a favorable long-term safety profile, according to Dr. Thompson.

“At this point, we believe that beti-cel is potentially curative for patients with TDT [transfusion-dependent beta-thalassemia],” Dr. Thompson said in the press conference.

This study answers one of the major outstanding questions about beti-cel and iron metabolism, according to Arielle L. Langer, MD, MPH, an instructor in medicine at Harvard Medical School and attending physician for adult thalassemia patients at Brigham and Women’s and Dana Farber Cancer Institute, both in Boston.

“Seeing the restoration of iron metabolism, it really takes us a step closer to really thinking the term ‘cure’ might truly apply,” Dr. Langer said in an interview.

Dr. Langer said she looks forward to “very long-term outcomes” of beti-cel-treated patients to see whether endocrinopathies and other long-term sequelae of TDT are also abated.

“This [study] is a great intermediate point, but really, when we think about how thalassemia harms and kills our patients, we really sometimes measure that in decades,” she said.

Beta-thalassemia is caused by mutations in the beta-globin gene, resulting in reduced levels of hemoglobin. Patients with TDT, the most serious form of the disease, have severe anemia and are often dependent on red blood cell transfusions from infancy onward, Dr. Thompson said.

With chronic transfusions needed to maintain hemoglobin levels, TDT patients inevitably experience iron overload, which can lead to organ damage and can be fatal. Consequently, patients will require lifelong iron chelation therapy, she added.

Beti-cel, an investigational ex vivo gene addition therapy currently under review by the U.S. Food and Drug Administration, involves adding functional copies of a modified form of the beta-globin gene into a patient’s own hematopoietic stem cells. Once those cells are reinfused, patients may produce adult hemoglobin at levels that eliminate the need for transfusions, according to Dr. Thompson.

At the meeting, Dr. Thompson reported on patients from two phase 1/2 and two phase 3 beti-cel clinical trials who subsequently enrolled in LTF-303, a 13-year follow-up study of the gene therapy’s safety and efficacy.

A total of 57 patients were included in this report, making it the largest gene therapy program to date in any blood disorder, according to Dr. Thompson. Before receiving beti-cel, the patients, who had a broad range of thalassemia genotypes, were receiving between 10 and almost 40 red blood cell transfusions per year, she reported.

Patients ranged in age from 5 to 35 years. The median age in the phase 1/2 studies was 20 years, while in the phase 3 studies it was 15 years.

“The early experience in the phase 1/2 trials allowed us to be more comfortable with enrolling more children, and that has actually helped us to understand safety and efficacy and children in the phase 3 setting,” Dr. Thompson said.

Fertility preservation measures had been undertaken by about 59% of patients from the phase 1/2 studies and 71% of patients from the phase 3 studies, the data show.

Among patients from the phase 3 beti-cel studies who could be evaluated, 31 out of 35 (or 89%) achieved durable transfusion independence, according to the investigator.

The median duration of ongoing transfusion independence was 32 months, with a range of about 18 to 49 months, she added.

Dr. Thompson also reported a subanalysis intended to assess iron status in 16 patients who restarted and then stopped chelation. That subanalysis demonstrated iron reduction in response to chelation, and then stabilization of iron markers after chelation was stopped. Post-gene therapy chelation led to reductions in liver iron concentration and serum ferritin that remained relatively stable after chelation was stopped, she said.

Serious adverse events occurred in eight patients in the long-term follow-up study. However, adverse events related to beti-cel have been absent beyond 2 years post-infusion, according to Dr. Thompson, who added that there have been no reported cases of replication-competent lentivirus, no clonal expansion, no insertional oncogenesis, and no malignancies observed.

“Very reassuringly, there have been 2 male patients, one of whom underwent fertility preservation, who report having healthy children with their partners,” she added.

Dr. Thompson provided disclosures related to Baxalta, Biomarin, bluebird bio, Inc., Celgene/BMS, CRISPR Therapeutics, Vertex, Editas, Graphite Bio, Novartis, Agios, Beam, and Global Blood Therapeutics.
 

In patients with transfusion-dependent beta-thalassemia, a single gene therapy infusion is capable of yielding durable transfusion independence and substantial improvements in iron overload, an investigator reported at the annual meeting of the American Society of Hematology.

Among patients who received betibeglogene autotemcel (beti-cel) in a phase 3 trial and enrolled in a long-term follow-up study, nearly 90% achieved durable transfusion independence, according to Alexis A. Thompson, MD, MPH, of the hematology section at the Ann & Robert H. Lurie Children’s Hospital of Chicago.

The median duration of ongoing transfusion independence was nearly 3 years as of this report, which Dr. Thompson described in a press conference at the meeting.

In a subanalysis of this international study, Dr. Thompson and co-investigators reported that in patients who achieve transfusion independence, chelation reduced iron, and iron markers stabilized even after chelation was stopped.

Beyond 2 years post-infusion, no adverse events related to the drug product were seen. This suggested that the therapy has a favorable long-term safety profile, according to Dr. Thompson.

“At this point, we believe that beti-cel is potentially curative for patients with TDT [transfusion-dependent beta-thalassemia],” Dr. Thompson said in the press conference.

This study answers one of the major outstanding questions about beti-cel and iron metabolism, according to Arielle L. Langer, MD, MPH, an instructor in medicine at Harvard Medical School and attending physician for adult thalassemia patients at Brigham and Women’s and Dana Farber Cancer Institute, both in Boston.

“Seeing the restoration of iron metabolism, it really takes us a step closer to really thinking the term ‘cure’ might truly apply,” Dr. Langer said in an interview.

Dr. Langer said she looks forward to “very long-term outcomes” of beti-cel-treated patients to see whether endocrinopathies and other long-term sequelae of TDT are also abated.

“This [study] is a great intermediate point, but really, when we think about how thalassemia harms and kills our patients, we really sometimes measure that in decades,” she said.

Beta-thalassemia is caused by mutations in the beta-globin gene, resulting in reduced levels of hemoglobin. Patients with TDT, the most serious form of the disease, have severe anemia and are often dependent on red blood cell transfusions from infancy onward, Dr. Thompson said.

With chronic transfusions needed to maintain hemoglobin levels, TDT patients inevitably experience iron overload, which can lead to organ damage and can be fatal. Consequently, patients will require lifelong iron chelation therapy, she added.

Beti-cel, an investigational ex vivo gene addition therapy currently under review by the U.S. Food and Drug Administration, involves adding functional copies of a modified form of the beta-globin gene into a patient’s own hematopoietic stem cells. Once those cells are reinfused, patients may produce adult hemoglobin at levels that eliminate the need for transfusions, according to Dr. Thompson.

At the meeting, Dr. Thompson reported on patients from two phase 1/2 and two phase 3 beti-cel clinical trials who subsequently enrolled in LTF-303, a 13-year follow-up study of the gene therapy’s safety and efficacy.

A total of 57 patients were included in this report, making it the largest gene therapy program to date in any blood disorder, according to Dr. Thompson. Before receiving beti-cel, the patients, who had a broad range of thalassemia genotypes, were receiving between 10 and almost 40 red blood cell transfusions per year, she reported.

Patients ranged in age from 5 to 35 years. The median age in the phase 1/2 studies was 20 years, while in the phase 3 studies it was 15 years.

“The early experience in the phase 1/2 trials allowed us to be more comfortable with enrolling more children, and that has actually helped us to understand safety and efficacy and children in the phase 3 setting,” Dr. Thompson said.

Fertility preservation measures had been undertaken by about 59% of patients from the phase 1/2 studies and 71% of patients from the phase 3 studies, the data show.

Among patients from the phase 3 beti-cel studies who could be evaluated, 31 out of 35 (or 89%) achieved durable transfusion independence, according to the investigator.

The median duration of ongoing transfusion independence was 32 months, with a range of about 18 to 49 months, she added.

Dr. Thompson also reported a subanalysis intended to assess iron status in 16 patients who restarted and then stopped chelation. That subanalysis demonstrated iron reduction in response to chelation, and then stabilization of iron markers after chelation was stopped. Post-gene therapy chelation led to reductions in liver iron concentration and serum ferritin that remained relatively stable after chelation was stopped, she said.

Serious adverse events occurred in eight patients in the long-term follow-up study. However, adverse events related to beti-cel have been absent beyond 2 years post-infusion, according to Dr. Thompson, who added that there have been no reported cases of replication-competent lentivirus, no clonal expansion, no insertional oncogenesis, and no malignancies observed.

“Very reassuringly, there have been 2 male patients, one of whom underwent fertility preservation, who report having healthy children with their partners,” she added.

Dr. Thompson provided disclosures related to Baxalta, Biomarin, bluebird bio, Inc., Celgene/BMS, CRISPR Therapeutics, Vertex, Editas, Graphite Bio, Novartis, Agios, Beam, and Global Blood Therapeutics.
 

A 46-year-old woman presents with fatigue. She reports that she has had unusually heavy periods for the past 6 months. Her blood work shows a hematocrit level of 32, a mean corpuscular volume of 77, a platelet count of 390,000, and a ferritin level of 5.

What would you recommend for iron replacement?

A. FeSO₄ 325 mg three times a day with vitamin C

B. FeSO₄ 325 mg daily with vitamin C

C. FeSO₄ 325 mg every other day

Recommendations and supporting research

I think I would start with choice C, FeSO₄ every other day.

Treatment of iron deficiency with oral iron has traditionally been done by giving 150-200 mg of elemental iron (which is equal to three 325 mg tablets of iron sulfate).¹ This dosing regimen has considerable gastrointestinal side effects. Recent evidence has shown that iron absorption is diminished the more frequently it is given.

Stoffel and colleagues found that fractional iron absorption was higher in iron-deficient women who were given iron every other day, compared with those who received daily iron.² They also found that the more frequently iron was administered, the higher the hepcidin levels were, and the lower the iron absorption.

Karacok and colleagues studied every other day iron versus daily iron for the treatment of iron-deficiency anemia of pregnancy.³ A total of 217 women completed randomization and participated in the study, with all women receiving 100 mg of elemental iron, either daily (111) or every other day (106). There was no significant difference in increase in ferritin levels, or hemoglobin increase between the groups. The daily iron group had more gastrointestinal symptoms (41.4%) than the every other day iron group (15.1%) (P < .0057).

Düzen Oflas and colleagues looked at the same question in nonpregnant women with iron deficiency anemia.⁴ Study patients either received 80 mg iron sulfate twice a day, 80 mg once a day, or 80 mg every other day. There was no statistically significant difference in hemoglobin improvement between groups, but the group that received twice a day dosing of iron had statistically significantly higher ferritin levels than the daily or every other day iron groups. This improvement in ferritin levels came at a cost, though, as 68% of patients in the twice daily iron group had gastrointestinal symptoms, compared with only 10% in the every other day iron group (P < .01).

Vitamin C is often recommended to be taken with iron to promote absorption. The evidence for this practice is scant, and dates back almost 50 years.^5,6

Cook and Reddy found there was no significant difference in mean iron absorption among the three dietary periods studied in 12 patients despite a range of mean daily intakes of dietary vitamin C of 51-247 mg/d.⁷

Hunt and colleagues studied 25 non pregnant, healthy women with low ferritin levels.⁸ The women’s meals were supplemented with vitamin C (500 mg, three times a day) for 5 of the 10 weeks, in a double-blind, crossover design. Vitamin C supplementation did not lead to a difference in iron absorption, lab indices of iron deficiency, or the biological half-life of iron.

Li and colleagues looked at the effect of vitamin C supplementation on iron levels in women with iron deficiency anemia.⁹ A total of 440 women were recruited, with 432 completing the trial. Women were randomized to receive iron supplements plus vitamin C or iron supplements only. Their findings were that oral iron supplements alone were equivalent to oral iron supplements plus vitamin C in improving hemoglobin recovery and iron absorption.
 

Bottom line

Less frequent administration of iron supplements (every other day) is as effective as more frequent administration, with less GI symptoms. Also, adding vitamin C does not appear to improve absorption of iron supplements.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. 1. Fairbanks VF and Beutler E. Iron deficiency, in “Williams Textbook of Hematology, 6th ed.” (New York: McGraw-Hill, 2001).

2. Stoffel N et al. Lancet Haematology. 2017;4: e524-33.

3. Karakoc G et al. J Matern Fetal Neonatal Med. 2021 Apr 18:1-5

4. Düzen Oflas N et al. Intern Med J. 2020 Jul;50(7):854-8

5. Cook JD and Monsen ER. Am J Clin Nutr. 1977;30:235-41.

6. Hallberg L etal. Hum Nutr Appl Nutr. 1986;40: 97-113.

7. Cook JD and Reddy M. Am J Clin Nutr. 2001;73:93-8.

8. Hunt JR et al. Am J Clin Nutr. 1994 Jun;59(6):1381-5.

9. Li N et al. JAMA Netw Open. 2020 Nov 2;3(11):e2023644.

A 46-year-old woman presents with fatigue. She reports that she has had unusually heavy periods for the past 6 months. Her blood work shows a hematocrit level of 32, a mean corpuscular volume of 77, a platelet count of 390,000, and a ferritin level of 5.

What would you recommend for iron replacement?

A. FeSO₄ 325 mg three times a day with vitamin C

B. FeSO₄ 325 mg daily with vitamin C

C. FeSO₄ 325 mg every other day

Recommendations and supporting research

I think I would start with choice C, FeSO₄ every other day.

Treatment of iron deficiency with oral iron has traditionally been done by giving 150-200 mg of elemental iron (which is equal to three 325 mg tablets of iron sulfate).¹ This dosing regimen has considerable gastrointestinal side effects. Recent evidence has shown that iron absorption is diminished the more frequently it is given.

Stoffel and colleagues found that fractional iron absorption was higher in iron-deficient women who were given iron every other day, compared with those who received daily iron.² They also found that the more frequently iron was administered, the higher the hepcidin levels were, and the lower the iron absorption.

Karacok and colleagues studied every other day iron versus daily iron for the treatment of iron-deficiency anemia of pregnancy.³ A total of 217 women completed randomization and participated in the study, with all women receiving 100 mg of elemental iron, either daily (111) or every other day (106). There was no significant difference in increase in ferritin levels, or hemoglobin increase between the groups. The daily iron group had more gastrointestinal symptoms (41.4%) than the every other day iron group (15.1%) (P < .0057).

Düzen Oflas and colleagues looked at the same question in nonpregnant women with iron deficiency anemia.⁴ Study patients either received 80 mg iron sulfate twice a day, 80 mg once a day, or 80 mg every other day. There was no statistically significant difference in hemoglobin improvement between groups, but the group that received twice a day dosing of iron had statistically significantly higher ferritin levels than the daily or every other day iron groups. This improvement in ferritin levels came at a cost, though, as 68% of patients in the twice daily iron group had gastrointestinal symptoms, compared with only 10% in the every other day iron group (P < .01).

Vitamin C is often recommended to be taken with iron to promote absorption. The evidence for this practice is scant, and dates back almost 50 years.^5,6

Cook and Reddy found there was no significant difference in mean iron absorption among the three dietary periods studied in 12 patients despite a range of mean daily intakes of dietary vitamin C of 51-247 mg/d.⁷

Hunt and colleagues studied 25 non pregnant, healthy women with low ferritin levels.⁸ The women’s meals were supplemented with vitamin C (500 mg, three times a day) for 5 of the 10 weeks, in a double-blind, crossover design. Vitamin C supplementation did not lead to a difference in iron absorption, lab indices of iron deficiency, or the biological half-life of iron.

Li and colleagues looked at the effect of vitamin C supplementation on iron levels in women with iron deficiency anemia.⁹ A total of 440 women were recruited, with 432 completing the trial. Women were randomized to receive iron supplements plus vitamin C or iron supplements only. Their findings were that oral iron supplements alone were equivalent to oral iron supplements plus vitamin C in improving hemoglobin recovery and iron absorption.
 

Bottom line

Less frequent administration of iron supplements (every other day) is as effective as more frequent administration, with less GI symptoms. Also, adding vitamin C does not appear to improve absorption of iron supplements.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. 1. Fairbanks VF and Beutler E. Iron deficiency, in “Williams Textbook of Hematology, 6th ed.” (New York: McGraw-Hill, 2001).

2. Stoffel N et al. Lancet Haematology. 2017;4: e524-33.

3. Karakoc G et al. J Matern Fetal Neonatal Med. 2021 Apr 18:1-5

4. Düzen Oflas N et al. Intern Med J. 2020 Jul;50(7):854-8

5. Cook JD and Monsen ER. Am J Clin Nutr. 1977;30:235-41.

6. Hallberg L etal. Hum Nutr Appl Nutr. 1986;40: 97-113.

7. Cook JD and Reddy M. Am J Clin Nutr. 2001;73:93-8.

8. Hunt JR et al. Am J Clin Nutr. 1994 Jun;59(6):1381-5.

9. Li N et al. JAMA Netw Open. 2020 Nov 2;3(11):e2023644.

A 46-year-old woman presents with fatigue. She reports that she has had unusually heavy periods for the past 6 months. Her blood work shows a hematocrit level of 32, a mean corpuscular volume of 77, a platelet count of 390,000, and a ferritin level of 5.

What would you recommend for iron replacement?

A. FeSO₄ 325 mg three times a day with vitamin C

B. FeSO₄ 325 mg daily with vitamin C

C. FeSO₄ 325 mg every other day

Recommendations and supporting research

I think I would start with choice C, FeSO₄ every other day.

Treatment of iron deficiency with oral iron has traditionally been done by giving 150-200 mg of elemental iron (which is equal to three 325 mg tablets of iron sulfate).¹ This dosing regimen has considerable gastrointestinal side effects. Recent evidence has shown that iron absorption is diminished the more frequently it is given.

Stoffel and colleagues found that fractional iron absorption was higher in iron-deficient women who were given iron every other day, compared with those who received daily iron.² They also found that the more frequently iron was administered, the higher the hepcidin levels were, and the lower the iron absorption.

Karacok and colleagues studied every other day iron versus daily iron for the treatment of iron-deficiency anemia of pregnancy.³ A total of 217 women completed randomization and participated in the study, with all women receiving 100 mg of elemental iron, either daily (111) or every other day (106). There was no significant difference in increase in ferritin levels, or hemoglobin increase between the groups. The daily iron group had more gastrointestinal symptoms (41.4%) than the every other day iron group (15.1%) (P < .0057).

Düzen Oflas and colleagues looked at the same question in nonpregnant women with iron deficiency anemia.⁴ Study patients either received 80 mg iron sulfate twice a day, 80 mg once a day, or 80 mg every other day. There was no statistically significant difference in hemoglobin improvement between groups, but the group that received twice a day dosing of iron had statistically significantly higher ferritin levels than the daily or every other day iron groups. This improvement in ferritin levels came at a cost, though, as 68% of patients in the twice daily iron group had gastrointestinal symptoms, compared with only 10% in the every other day iron group (P < .01).

Vitamin C is often recommended to be taken with iron to promote absorption. The evidence for this practice is scant, and dates back almost 50 years.^5,6

Cook and Reddy found there was no significant difference in mean iron absorption among the three dietary periods studied in 12 patients despite a range of mean daily intakes of dietary vitamin C of 51-247 mg/d.⁷

Hunt and colleagues studied 25 non pregnant, healthy women with low ferritin levels.⁸ The women’s meals were supplemented with vitamin C (500 mg, three times a day) for 5 of the 10 weeks, in a double-blind, crossover design. Vitamin C supplementation did not lead to a difference in iron absorption, lab indices of iron deficiency, or the biological half-life of iron.

Li and colleagues looked at the effect of vitamin C supplementation on iron levels in women with iron deficiency anemia.⁹ A total of 440 women were recruited, with 432 completing the trial. Women were randomized to receive iron supplements plus vitamin C or iron supplements only. Their findings were that oral iron supplements alone were equivalent to oral iron supplements plus vitamin C in improving hemoglobin recovery and iron absorption.
 

Bottom line

Less frequent administration of iron supplements (every other day) is as effective as more frequent administration, with less GI symptoms. Also, adding vitamin C does not appear to improve absorption of iron supplements.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. He is a member of the editorial advisory board of Internal Medicine News. Dr. Paauw has no conflicts to disclose. Contact him at [email protected].

References

1. 1. Fairbanks VF and Beutler E. Iron deficiency, in “Williams Textbook of Hematology, 6th ed.” (New York: McGraw-Hill, 2001).

2. Stoffel N et al. Lancet Haematology. 2017;4: e524-33.

3. Karakoc G et al. J Matern Fetal Neonatal Med. 2021 Apr 18:1-5

4. Düzen Oflas N et al. Intern Med J. 2020 Jul;50(7):854-8

5. Cook JD and Monsen ER. Am J Clin Nutr. 1977;30:235-41.

6. Hallberg L etal. Hum Nutr Appl Nutr. 1986;40: 97-113.

7. Cook JD and Reddy M. Am J Clin Nutr. 2001;73:93-8.

8. Hunt JR et al. Am J Clin Nutr. 1994 Jun;59(6):1381-5.

9. Li N et al. JAMA Netw Open. 2020 Nov 2;3(11):e2023644.

Adults with sickle cell disease who experienced a vaso-occlusive crisis had substantially better outcomes when they were treated at specialty infusion centers than those treated in emergency departments (EDs), a prospective observational study shows.

At infusion centers, patients received pain medication an average of 70 minutes faster compared with patients treated in EDs (62 vs. 132 minutes), according to a study published online in the Annals of Internal Medicine. In addition, patients at infusion centers were 3.8 times more likely to have their pain reassessed within 30 minutes of the first dose. And they were 4 times more likely to be discharged home, the researchers found.

“It’s not that the emergency room doctors don’t want to do the right thing,” study author Sophie Lanzkron, MD, said in an interview. “They do, but they aren’t experts in sickle cell disease. They work in an emergency room, which is an incredibly busy, stressful place where they see trauma and heart attacks and strokes and all of these things that need emergency care. And so it just is not the right setting to treat people with sickle cell disease.”

To assess whether care at specialty infusion centers or EDs leads to better outcomes for patients with sickle cell disease with uncomplicated vaso-occlusive crises, Dr. Lanzkron, director of the Sickle Cell Center for Adults at the Johns Hopkins Hospital, Baltimore, and colleagues conducted the ESCAPED (Examining Sickle Cell Acute Pain in the Emergency vs. Day Hospital) study.

The trial included 483 adults with sickle cell disease who lived within 60 miles of an infusion center in four U.S. cities: Baltimore, Maryland; Cleveland, Ohio; Milwaukee, Wisconsin; and Baton Rouge, Louisiana. Investigators recruited patients between April 2015 and December 2016 and followed them for 18 months after enrollment.

The present analysis focused on data from 269 participants who had infusion center visits or ED visits that occurred during weekdays when infusion centers were open. Two sites had infusion centers solely for adults with sickle cell disease (Baltimore and Milwaukee), and two infusion centers shared infusion space with other hematology-oncology patients. All four sites were in hospitals that also had EDs. 

Although participants may have received comprehensive care at one of the sites with an infusion center, those who lived farther from an infusion center were likely to receive care for acute pain at an ED closer to home, the authors explain in the article.

The investigators used propensity score methodology to balance patient characteristics in the study groups.
 

Quick, effective pain reduction is beneficial

The results suggest that infusion centers “are more likely to provide guideline-based care than EDs,” and this care “can improve overall outcomes,” the authors write. 

Although the specialty infusion centers the researchers studied used various models, similar outcomes were seen at all of them.

The study did not include patients who had complications of sickle cell disease in addition to vaso-occlusive crisis, the researchers note. 

“[Because] the magnitude of the treatment effects estimated in our study is large and we have captured most of the important potential confounders, an unmeasured confounder that can nullify the treatment effect is unlikely to exist,” the authors write. 

“Sickle cell disease is a complicated condition that affects multiple organs. Patients who present with acute pain will have better outcomes being treated under providers who know and understand the disease,” commented Julie Kanter, MD, director of the adult sickle cell disease program and codirector of the Comprehensive Sickle Cell Center at the University of Alabama at Birmingham. “Specialized infusion centers offer the opportunity to both improve outcomes and decrease the cost of care. Most importantly, it is better for the individual with sickle cell disease,” she said.

Dr. Kanter wrote an accompanying editorial about the ESCAPED findings. The editorialist notes that “opioid medications are the only option to reduce the pain caused by microvascular injury” in patients with sickle cell crisis, although these treatments do not reduce the underlying damage and have substantial side effects and risks. Nevertheless, “quick and effective reduction of pain can allow patients to more easily move, stretch, and breathe ... important to increase oxygenation and restore blood flow, which will eventually abate the crisis,” Dr. Kanter wrote. 

The study shows that the infusion center treatment approach can benefit patients across different settings, commented John J. Strouse, MD, PhD, medical director of the adult sickle cell program at Duke University Sickle Cell Center, Durham, N.C., who was not involved in the study. 

“They show that they can definitely get closer to the recommendations of guidelines for acute pain management and sickle cell disease” in a setting that is focused on one problem, he said. “The other piece that is really important is that people are much more likely to go home if you follow the guideline.”
 

Infusion centers are scarce

“These systems need to be built,” Dr. Lanzkron said. “In most places, patients don’t have access to the infusion center model for their care. And in some places, it is not going to be practical.” Still, there may be ways to establish infusion locations, such as at oncology centers. And while there are challenges to delivering sickle cell disease care in EDs, “emergency rooms need to try to meet the needs of this patient population as best as they can,” Dr. Lanzkron said.

“Structural racism has played a role in the quality of care delivered” to patients with sickle cell disease, Dr. Lanzkron said. “The big message is [that] there is a better way to do this.” 

The study was funded by the Patient-Centered Outcomes Research Institute. Dr. Lanzkron’s disclosures included grants or contracts with government agencies and companies that are paid to her institution, as well as consulting fees from Bluebird Bio, Novo Nordisk, and Pfizer. Coauthors have disclosed working with sickle cell organizations and various medical companies. Dr. Kanter and Dr. Strouse have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Adults with sickle cell disease who experienced a vaso-occlusive crisis had substantially better outcomes when they were treated at specialty infusion centers than those treated in emergency departments (EDs), a prospective observational study shows.

At infusion centers, patients received pain medication an average of 70 minutes faster compared with patients treated in EDs (62 vs. 132 minutes), according to a study published online in the Annals of Internal Medicine. In addition, patients at infusion centers were 3.8 times more likely to have their pain reassessed within 30 minutes of the first dose. And they were 4 times more likely to be discharged home, the researchers found.

“It’s not that the emergency room doctors don’t want to do the right thing,” study author Sophie Lanzkron, MD, said in an interview. “They do, but they aren’t experts in sickle cell disease. They work in an emergency room, which is an incredibly busy, stressful place where they see trauma and heart attacks and strokes and all of these things that need emergency care. And so it just is not the right setting to treat people with sickle cell disease.”

To assess whether care at specialty infusion centers or EDs leads to better outcomes for patients with sickle cell disease with uncomplicated vaso-occlusive crises, Dr. Lanzkron, director of the Sickle Cell Center for Adults at the Johns Hopkins Hospital, Baltimore, and colleagues conducted the ESCAPED (Examining Sickle Cell Acute Pain in the Emergency vs. Day Hospital) study.

The trial included 483 adults with sickle cell disease who lived within 60 miles of an infusion center in four U.S. cities: Baltimore, Maryland; Cleveland, Ohio; Milwaukee, Wisconsin; and Baton Rouge, Louisiana. Investigators recruited patients between April 2015 and December 2016 and followed them for 18 months after enrollment.

The present analysis focused on data from 269 participants who had infusion center visits or ED visits that occurred during weekdays when infusion centers were open. Two sites had infusion centers solely for adults with sickle cell disease (Baltimore and Milwaukee), and two infusion centers shared infusion space with other hematology-oncology patients. All four sites were in hospitals that also had EDs. 

Although participants may have received comprehensive care at one of the sites with an infusion center, those who lived farther from an infusion center were likely to receive care for acute pain at an ED closer to home, the authors explain in the article.

The investigators used propensity score methodology to balance patient characteristics in the study groups.
 

Quick, effective pain reduction is beneficial

The results suggest that infusion centers “are more likely to provide guideline-based care than EDs,” and this care “can improve overall outcomes,” the authors write. 

Although the specialty infusion centers the researchers studied used various models, similar outcomes were seen at all of them.

The study did not include patients who had complications of sickle cell disease in addition to vaso-occlusive crisis, the researchers note. 

“[Because] the magnitude of the treatment effects estimated in our study is large and we have captured most of the important potential confounders, an unmeasured confounder that can nullify the treatment effect is unlikely to exist,” the authors write. 

“Sickle cell disease is a complicated condition that affects multiple organs. Patients who present with acute pain will have better outcomes being treated under providers who know and understand the disease,” commented Julie Kanter, MD, director of the adult sickle cell disease program and codirector of the Comprehensive Sickle Cell Center at the University of Alabama at Birmingham. “Specialized infusion centers offer the opportunity to both improve outcomes and decrease the cost of care. Most importantly, it is better for the individual with sickle cell disease,” she said.

Dr. Kanter wrote an accompanying editorial about the ESCAPED findings. The editorialist notes that “opioid medications are the only option to reduce the pain caused by microvascular injury” in patients with sickle cell crisis, although these treatments do not reduce the underlying damage and have substantial side effects and risks. Nevertheless, “quick and effective reduction of pain can allow patients to more easily move, stretch, and breathe ... important to increase oxygenation and restore blood flow, which will eventually abate the crisis,” Dr. Kanter wrote. 

The study shows that the infusion center treatment approach can benefit patients across different settings, commented John J. Strouse, MD, PhD, medical director of the adult sickle cell program at Duke University Sickle Cell Center, Durham, N.C., who was not involved in the study. 

“They show that they can definitely get closer to the recommendations of guidelines for acute pain management and sickle cell disease” in a setting that is focused on one problem, he said. “The other piece that is really important is that people are much more likely to go home if you follow the guideline.”
 

Infusion centers are scarce

“These systems need to be built,” Dr. Lanzkron said. “In most places, patients don’t have access to the infusion center model for their care. And in some places, it is not going to be practical.” Still, there may be ways to establish infusion locations, such as at oncology centers. And while there are challenges to delivering sickle cell disease care in EDs, “emergency rooms need to try to meet the needs of this patient population as best as they can,” Dr. Lanzkron said.

“Structural racism has played a role in the quality of care delivered” to patients with sickle cell disease, Dr. Lanzkron said. “The big message is [that] there is a better way to do this.” 

The study was funded by the Patient-Centered Outcomes Research Institute. Dr. Lanzkron’s disclosures included grants or contracts with government agencies and companies that are paid to her institution, as well as consulting fees from Bluebird Bio, Novo Nordisk, and Pfizer. Coauthors have disclosed working with sickle cell organizations and various medical companies. Dr. Kanter and Dr. Strouse have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Adults with sickle cell disease who experienced a vaso-occlusive crisis had substantially better outcomes when they were treated at specialty infusion centers than those treated in emergency departments (EDs), a prospective observational study shows.

At infusion centers, patients received pain medication an average of 70 minutes faster compared with patients treated in EDs (62 vs. 132 minutes), according to a study published online in the Annals of Internal Medicine. In addition, patients at infusion centers were 3.8 times more likely to have their pain reassessed within 30 minutes of the first dose. And they were 4 times more likely to be discharged home, the researchers found.

“It’s not that the emergency room doctors don’t want to do the right thing,” study author Sophie Lanzkron, MD, said in an interview. “They do, but they aren’t experts in sickle cell disease. They work in an emergency room, which is an incredibly busy, stressful place where they see trauma and heart attacks and strokes and all of these things that need emergency care. And so it just is not the right setting to treat people with sickle cell disease.”

To assess whether care at specialty infusion centers or EDs leads to better outcomes for patients with sickle cell disease with uncomplicated vaso-occlusive crises, Dr. Lanzkron, director of the Sickle Cell Center for Adults at the Johns Hopkins Hospital, Baltimore, and colleagues conducted the ESCAPED (Examining Sickle Cell Acute Pain in the Emergency vs. Day Hospital) study.

The trial included 483 adults with sickle cell disease who lived within 60 miles of an infusion center in four U.S. cities: Baltimore, Maryland; Cleveland, Ohio; Milwaukee, Wisconsin; and Baton Rouge, Louisiana. Investigators recruited patients between April 2015 and December 2016 and followed them for 18 months after enrollment.

The present analysis focused on data from 269 participants who had infusion center visits or ED visits that occurred during weekdays when infusion centers were open. Two sites had infusion centers solely for adults with sickle cell disease (Baltimore and Milwaukee), and two infusion centers shared infusion space with other hematology-oncology patients. All four sites were in hospitals that also had EDs. 

Although participants may have received comprehensive care at one of the sites with an infusion center, those who lived farther from an infusion center were likely to receive care for acute pain at an ED closer to home, the authors explain in the article.

The investigators used propensity score methodology to balance patient characteristics in the study groups.
 

Quick, effective pain reduction is beneficial

The results suggest that infusion centers “are more likely to provide guideline-based care than EDs,” and this care “can improve overall outcomes,” the authors write. 

Although the specialty infusion centers the researchers studied used various models, similar outcomes were seen at all of them.

The study did not include patients who had complications of sickle cell disease in addition to vaso-occlusive crisis, the researchers note. 

“[Because] the magnitude of the treatment effects estimated in our study is large and we have captured most of the important potential confounders, an unmeasured confounder that can nullify the treatment effect is unlikely to exist,” the authors write. 

“Sickle cell disease is a complicated condition that affects multiple organs. Patients who present with acute pain will have better outcomes being treated under providers who know and understand the disease,” commented Julie Kanter, MD, director of the adult sickle cell disease program and codirector of the Comprehensive Sickle Cell Center at the University of Alabama at Birmingham. “Specialized infusion centers offer the opportunity to both improve outcomes and decrease the cost of care. Most importantly, it is better for the individual with sickle cell disease,” she said.

Dr. Kanter wrote an accompanying editorial about the ESCAPED findings. The editorialist notes that “opioid medications are the only option to reduce the pain caused by microvascular injury” in patients with sickle cell crisis, although these treatments do not reduce the underlying damage and have substantial side effects and risks. Nevertheless, “quick and effective reduction of pain can allow patients to more easily move, stretch, and breathe ... important to increase oxygenation and restore blood flow, which will eventually abate the crisis,” Dr. Kanter wrote. 

The study shows that the infusion center treatment approach can benefit patients across different settings, commented John J. Strouse, MD, PhD, medical director of the adult sickle cell program at Duke University Sickle Cell Center, Durham, N.C., who was not involved in the study. 

“They show that they can definitely get closer to the recommendations of guidelines for acute pain management and sickle cell disease” in a setting that is focused on one problem, he said. “The other piece that is really important is that people are much more likely to go home if you follow the guideline.”
 

Infusion centers are scarce

“These systems need to be built,” Dr. Lanzkron said. “In most places, patients don’t have access to the infusion center model for their care. And in some places, it is not going to be practical.” Still, there may be ways to establish infusion locations, such as at oncology centers. And while there are challenges to delivering sickle cell disease care in EDs, “emergency rooms need to try to meet the needs of this patient population as best as they can,” Dr. Lanzkron said.

“Structural racism has played a role in the quality of care delivered” to patients with sickle cell disease, Dr. Lanzkron said. “The big message is [that] there is a better way to do this.” 

The study was funded by the Patient-Centered Outcomes Research Institute. Dr. Lanzkron’s disclosures included grants or contracts with government agencies and companies that are paid to her institution, as well as consulting fees from Bluebird Bio, Novo Nordisk, and Pfizer. Coauthors have disclosed working with sickle cell organizations and various medical companies. Dr. Kanter and Dr. Strouse have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Findings from a phase 3 trial failed to support those from a prior study showing that poloxamer 188 shortened painful vaso-occlusive episodes in sickle cell disease.

Poloxamer 188, a nonionic block polymer surfactant reported to reduce blood viscosity and cell-cell interactions, failed to shorten painful vaso-occlusive episodes in adults and children with sickle cell disease (SCD) in a randomized, placebo-controlled, phase 3 trial.

The findings contrast with those from a prior phase 3 trial showing benefits with treatment, James F. Casella, MD, professor of pediatrics and chief of pediatric hematology at Johns Hopkins University, Baltimore, and colleagues reported.

The time from randomization to the last dose of parenteral opioids in the current study did not differ in 194 patients randomized to the active treatment and 194 randomized to a placebo group (81.8 hours with poloxamer 188 vs. 77.8 hours with placebo), the authors found.

The study results were reported online in JAMA.

Participants in the double-blind study were individuals aged 4-65 years (mean, 15.2 years) with acute moderate to severe painful vaso-occlusive episodes requiring hospitalization. They were recruited between May 2013 and February 2016 from 66 hospitals in 12 countries.

Adverse events that were more common in the poloxamer 188 group included hyperbilirubinemia, which occurred in 12.7% of patients versus 5.2% in the placebo group. Hypoxia occurred more often in the placebo group (12.0% vs. 5.3%).

“Poloxamer 188 has been evaluated in three clinical trials of SCD demonstrating safety and possible efficacy for painful vaso-occlusive episodes and acute chest syndrome, which involves intrapulmonary vascular occlusion and/or infection,” the authors noted. “These studies included a previous phase 3 trial that suggested efficacy for painful vaso-occlusive episodes, particularly in children and participants receiving hydroxyurea.”

The mean duration of vaso-occlusive crisis was reduced by 8.8 hours overall, by 21 hours in those aged under 16 years, and by 16 hours in those receiving hydroxyurea. A small, nonsignificant difference was also seen in the incidence of acute chest syndrome for children in that study.

The findings were encouraging given the lack of disease-modifying therapies for ongoing painful vaso-occlusive episodes, which are associated with higher mortality in patients with SCD; although three agents are available for the prevention vaso-occlusive episodes, including hydroxyurea, L-glutamine, and crizanlizumab-tmca, no available agent effectively manages vaso-occlusive episodes once they have begun, the authors noted.

Current treatment therefore remains supportive, with analgesia and hydration, they added.

This is concerning since “acute pain is estimated to account for 95% of hospital admissions for those with SCD, creating a burden for individuals with SCD, their families, and health care systems,” they explained, adding that the ability to reduce the severity and duration of vaso-occlusive episodes would be a significant advance.

“Because intravenous poloxamer 188 is neither approved by the Food and Drug Administration nor available for clinical use and because other drugs for managing ongoing vaso-occlusive episodes are absent, the present trial was designed to determine whether poloxamer 188 is efficacious for painful vaso-occlusive episodes in SCD,” they said.

However, no benefit was seen for episode duration with treatment in the current study, nor was any beneficial effect on acute chest syndrome observed.

“Rather, although not statistically significant, there were more participants younger than 16 years who developed acute chest syndrome in the poloxamer 188 group than in the placebo group, paralleling the direction of effects on the primary outcome for participants younger than 16 years [in the current study],” they wrote, adding that there were also “no apparent effects on readmission for painful vaso-occlusive episodes in participants receiving hydroxyurea, despite the known effect of hydroxyurea in reducing rates of painful vaso-occlusive episodes and acute chest syndrome.”

Though limited by subjective aspects of assessing the primary outcome in this study and by challenges with effectively blinding poloxamer 188 use, the current findings do not support the use of poloxamer 188 for vaso-occlusive episodes, they concluded.

In an accompanying editorial, JAMA deputy editor Jody Zylke, MD, suggested that the most likely explanation for the differing conclusions in the current and prior phase 3 trials relates to the choice of primary outcome.

In the prior study, the primary outcome was time from randomization to crisis resolution.

“The resolution of pain is subjective, and the criteria to determine crisis resolution established by the investigators were extremely stringent and difficult to implement, leading to a high proportion of participants with incomplete documentation,” Dr. Zylke noted. “Also, incomplete documentation occurred more often in the placebo group than the intervention group, resulting in more imputation of missing values for the placebo group, which favored the poloxamer 188 group.”

In the current trial, a “more easily verified primary outcome was selected, with data available for 99% of participants.”

The report by Dr. Casella and colleagues “adds to the evidence base and illustrates some of the challenges in finding effective treatments for patients with sickle cell disease,” he said.

This study was funded by Mast Therapeutics (previously Adventrx Therapeutics). Dr. Casella reported receiving grants from Mast Therapeutics and receiving an honorarium, travel expenses, and salary support through Johns Hopkins for providing consultative advice to Mast Pharmaceuticals during development of the clinical trial and for serving as the principal investigator for the clinical trial; being an inventor and a named party on a patent and licensing agreement to ImmunArray through Johns Hopkins for a panel of brain biomarkers for the detection of brain injury; and holding a patent for aptamers as a potential treatment for sickle cell disease. Dr. Zylke reported having no disclosures.

[email protected]

Findings from a phase 3 trial failed to support those from a prior study showing that poloxamer 188 shortened painful vaso-occlusive episodes in sickle cell disease.

Poloxamer 188, a nonionic block polymer surfactant reported to reduce blood viscosity and cell-cell interactions, failed to shorten painful vaso-occlusive episodes in adults and children with sickle cell disease (SCD) in a randomized, placebo-controlled, phase 3 trial.

The findings contrast with those from a prior phase 3 trial showing benefits with treatment, James F. Casella, MD, professor of pediatrics and chief of pediatric hematology at Johns Hopkins University, Baltimore, and colleagues reported.

The time from randomization to the last dose of parenteral opioids in the current study did not differ in 194 patients randomized to the active treatment and 194 randomized to a placebo group (81.8 hours with poloxamer 188 vs. 77.8 hours with placebo), the authors found.

The study results were reported online in JAMA.

Participants in the double-blind study were individuals aged 4-65 years (mean, 15.2 years) with acute moderate to severe painful vaso-occlusive episodes requiring hospitalization. They were recruited between May 2013 and February 2016 from 66 hospitals in 12 countries.

Adverse events that were more common in the poloxamer 188 group included hyperbilirubinemia, which occurred in 12.7% of patients versus 5.2% in the placebo group. Hypoxia occurred more often in the placebo group (12.0% vs. 5.3%).

“Poloxamer 188 has been evaluated in three clinical trials of SCD demonstrating safety and possible efficacy for painful vaso-occlusive episodes and acute chest syndrome, which involves intrapulmonary vascular occlusion and/or infection,” the authors noted. “These studies included a previous phase 3 trial that suggested efficacy for painful vaso-occlusive episodes, particularly in children and participants receiving hydroxyurea.”

The mean duration of vaso-occlusive crisis was reduced by 8.8 hours overall, by 21 hours in those aged under 16 years, and by 16 hours in those receiving hydroxyurea. A small, nonsignificant difference was also seen in the incidence of acute chest syndrome for children in that study.

The findings were encouraging given the lack of disease-modifying therapies for ongoing painful vaso-occlusive episodes, which are associated with higher mortality in patients with SCD; although three agents are available for the prevention vaso-occlusive episodes, including hydroxyurea, L-glutamine, and crizanlizumab-tmca, no available agent effectively manages vaso-occlusive episodes once they have begun, the authors noted.

Current treatment therefore remains supportive, with analgesia and hydration, they added.

This is concerning since “acute pain is estimated to account for 95% of hospital admissions for those with SCD, creating a burden for individuals with SCD, their families, and health care systems,” they explained, adding that the ability to reduce the severity and duration of vaso-occlusive episodes would be a significant advance.

“Because intravenous poloxamer 188 is neither approved by the Food and Drug Administration nor available for clinical use and because other drugs for managing ongoing vaso-occlusive episodes are absent, the present trial was designed to determine whether poloxamer 188 is efficacious for painful vaso-occlusive episodes in SCD,” they said.

However, no benefit was seen for episode duration with treatment in the current study, nor was any beneficial effect on acute chest syndrome observed.

“Rather, although not statistically significant, there were more participants younger than 16 years who developed acute chest syndrome in the poloxamer 188 group than in the placebo group, paralleling the direction of effects on the primary outcome for participants younger than 16 years [in the current study],” they wrote, adding that there were also “no apparent effects on readmission for painful vaso-occlusive episodes in participants receiving hydroxyurea, despite the known effect of hydroxyurea in reducing rates of painful vaso-occlusive episodes and acute chest syndrome.”

Though limited by subjective aspects of assessing the primary outcome in this study and by challenges with effectively blinding poloxamer 188 use, the current findings do not support the use of poloxamer 188 for vaso-occlusive episodes, they concluded.

In an accompanying editorial, JAMA deputy editor Jody Zylke, MD, suggested that the most likely explanation for the differing conclusions in the current and prior phase 3 trials relates to the choice of primary outcome.

In the prior study, the primary outcome was time from randomization to crisis resolution.

“The resolution of pain is subjective, and the criteria to determine crisis resolution established by the investigators were extremely stringent and difficult to implement, leading to a high proportion of participants with incomplete documentation,” Dr. Zylke noted. “Also, incomplete documentation occurred more often in the placebo group than the intervention group, resulting in more imputation of missing values for the placebo group, which favored the poloxamer 188 group.”

In the current trial, a “more easily verified primary outcome was selected, with data available for 99% of participants.”

The report by Dr. Casella and colleagues “adds to the evidence base and illustrates some of the challenges in finding effective treatments for patients with sickle cell disease,” he said.

This study was funded by Mast Therapeutics (previously Adventrx Therapeutics). Dr. Casella reported receiving grants from Mast Therapeutics and receiving an honorarium, travel expenses, and salary support through Johns Hopkins for providing consultative advice to Mast Pharmaceuticals during development of the clinical trial and for serving as the principal investigator for the clinical trial; being an inventor and a named party on a patent and licensing agreement to ImmunArray through Johns Hopkins for a panel of brain biomarkers for the detection of brain injury; and holding a patent for aptamers as a potential treatment for sickle cell disease. Dr. Zylke reported having no disclosures.

[email protected]

Findings from a phase 3 trial failed to support those from a prior study showing that poloxamer 188 shortened painful vaso-occlusive episodes in sickle cell disease.

Poloxamer 188, a nonionic block polymer surfactant reported to reduce blood viscosity and cell-cell interactions, failed to shorten painful vaso-occlusive episodes in adults and children with sickle cell disease (SCD) in a randomized, placebo-controlled, phase 3 trial.

The findings contrast with those from a prior phase 3 trial showing benefits with treatment, James F. Casella, MD, professor of pediatrics and chief of pediatric hematology at Johns Hopkins University, Baltimore, and colleagues reported.

The time from randomization to the last dose of parenteral opioids in the current study did not differ in 194 patients randomized to the active treatment and 194 randomized to a placebo group (81.8 hours with poloxamer 188 vs. 77.8 hours with placebo), the authors found.

The study results were reported online in JAMA.

Participants in the double-blind study were individuals aged 4-65 years (mean, 15.2 years) with acute moderate to severe painful vaso-occlusive episodes requiring hospitalization. They were recruited between May 2013 and February 2016 from 66 hospitals in 12 countries.

Adverse events that were more common in the poloxamer 188 group included hyperbilirubinemia, which occurred in 12.7% of patients versus 5.2% in the placebo group. Hypoxia occurred more often in the placebo group (12.0% vs. 5.3%).

“Poloxamer 188 has been evaluated in three clinical trials of SCD demonstrating safety and possible efficacy for painful vaso-occlusive episodes and acute chest syndrome, which involves intrapulmonary vascular occlusion and/or infection,” the authors noted. “These studies included a previous phase 3 trial that suggested efficacy for painful vaso-occlusive episodes, particularly in children and participants receiving hydroxyurea.”

The mean duration of vaso-occlusive crisis was reduced by 8.8 hours overall, by 21 hours in those aged under 16 years, and by 16 hours in those receiving hydroxyurea. A small, nonsignificant difference was also seen in the incidence of acute chest syndrome for children in that study.

The findings were encouraging given the lack of disease-modifying therapies for ongoing painful vaso-occlusive episodes, which are associated with higher mortality in patients with SCD; although three agents are available for the prevention vaso-occlusive episodes, including hydroxyurea, L-glutamine, and crizanlizumab-tmca, no available agent effectively manages vaso-occlusive episodes once they have begun, the authors noted.

Current treatment therefore remains supportive, with analgesia and hydration, they added.

This is concerning since “acute pain is estimated to account for 95% of hospital admissions for those with SCD, creating a burden for individuals with SCD, their families, and health care systems,” they explained, adding that the ability to reduce the severity and duration of vaso-occlusive episodes would be a significant advance.

“Because intravenous poloxamer 188 is neither approved by the Food and Drug Administration nor available for clinical use and because other drugs for managing ongoing vaso-occlusive episodes are absent, the present trial was designed to determine whether poloxamer 188 is efficacious for painful vaso-occlusive episodes in SCD,” they said.

However, no benefit was seen for episode duration with treatment in the current study, nor was any beneficial effect on acute chest syndrome observed.

“Rather, although not statistically significant, there were more participants younger than 16 years who developed acute chest syndrome in the poloxamer 188 group than in the placebo group, paralleling the direction of effects on the primary outcome for participants younger than 16 years [in the current study],” they wrote, adding that there were also “no apparent effects on readmission for painful vaso-occlusive episodes in participants receiving hydroxyurea, despite the known effect of hydroxyurea in reducing rates of painful vaso-occlusive episodes and acute chest syndrome.”

Though limited by subjective aspects of assessing the primary outcome in this study and by challenges with effectively blinding poloxamer 188 use, the current findings do not support the use of poloxamer 188 for vaso-occlusive episodes, they concluded.

In an accompanying editorial, JAMA deputy editor Jody Zylke, MD, suggested that the most likely explanation for the differing conclusions in the current and prior phase 3 trials relates to the choice of primary outcome.

In the prior study, the primary outcome was time from randomization to crisis resolution.

“The resolution of pain is subjective, and the criteria to determine crisis resolution established by the investigators were extremely stringent and difficult to implement, leading to a high proportion of participants with incomplete documentation,” Dr. Zylke noted. “Also, incomplete documentation occurred more often in the placebo group than the intervention group, resulting in more imputation of missing values for the placebo group, which favored the poloxamer 188 group.”

In the current trial, a “more easily verified primary outcome was selected, with data available for 99% of participants.”

The report by Dr. Casella and colleagues “adds to the evidence base and illustrates some of the challenges in finding effective treatments for patients with sickle cell disease,” he said.

This study was funded by Mast Therapeutics (previously Adventrx Therapeutics). Dr. Casella reported receiving grants from Mast Therapeutics and receiving an honorarium, travel expenses, and salary support through Johns Hopkins for providing consultative advice to Mast Pharmaceuticals during development of the clinical trial and for serving as the principal investigator for the clinical trial; being an inventor and a named party on a patent and licensing agreement to ImmunArray through Johns Hopkins for a panel of brain biomarkers for the detection of brain injury; and holding a patent for aptamers as a potential treatment for sickle cell disease. Dr. Zylke reported having no disclosures.

[email protected]

A rare, life-threatening anemia now has a new treatment option. The Food and Drug Administration announced the approval of pegcetacoplan (Empaveli) injection to treat adults with paroxysmal nocturnal hemoglobinuria (PNH). Pegcetacoplan is the first PNH treatment that binds to complement protein C3, according to the FDA announcement. Complement protein C3 is a key component of host immunity and defense.

Special concern

Because of the risk of severe side effects, the drug is available only through a restricted program under a risk evaluation and mitigation strategy (REMS). Serious infections can occur in patients taking pegcetacoplan that can become life-threatening or fatal if not treated early. According to the FDA, REMS are designed to reinforce medication use behaviors and actions that support the safe use of that medication, and only a few drugs require a REMS.

The most common other side effects are injection site reactions, diarrhea, abdominal pain, and fatigue.

Pegcetacoplan was approved based upon a study of 80 patients with PNH and anemia who had been taking eculizumab, a previously approved treatment. During 16 weeks of treatment, patients in the pegcetacoplan group had an average increase in their hemoglobin of 2.4 g/dL, while patients in the eculizumab group had an average decrease in their hemoglobin of 1.5 g/dL.
 

About the disease

PNH is caused by gene mutations that affect red blood cells, causing them to be defective and susceptible to destruction by a patient’s own immune system. Red blood cells in people with these mutations are defective and can be destroyed by the immune system, causing anemia.

Other symptoms include blood clots and destruction of bone marrow. The disease affects 1-1.5 people per million, with diagnosis typically occurring around ages 35-40, and a median survival of only 10 years after diagnosis, according to the FDA.

[email protected]

A rare, life-threatening anemia now has a new treatment option. The Food and Drug Administration announced the approval of pegcetacoplan (Empaveli) injection to treat adults with paroxysmal nocturnal hemoglobinuria (PNH). Pegcetacoplan is the first PNH treatment that binds to complement protein C3, according to the FDA announcement. Complement protein C3 is a key component of host immunity and defense.

Special concern

Because of the risk of severe side effects, the drug is available only through a restricted program under a risk evaluation and mitigation strategy (REMS). Serious infections can occur in patients taking pegcetacoplan that can become life-threatening or fatal if not treated early. According to the FDA, REMS are designed to reinforce medication use behaviors and actions that support the safe use of that medication, and only a few drugs require a REMS.

The most common other side effects are injection site reactions, diarrhea, abdominal pain, and fatigue.

Pegcetacoplan was approved based upon a study of 80 patients with PNH and anemia who had been taking eculizumab, a previously approved treatment. During 16 weeks of treatment, patients in the pegcetacoplan group had an average increase in their hemoglobin of 2.4 g/dL, while patients in the eculizumab group had an average decrease in their hemoglobin of 1.5 g/dL.
 

About the disease

PNH is caused by gene mutations that affect red blood cells, causing them to be defective and susceptible to destruction by a patient’s own immune system. Red blood cells in people with these mutations are defective and can be destroyed by the immune system, causing anemia.

Other symptoms include blood clots and destruction of bone marrow. The disease affects 1-1.5 people per million, with diagnosis typically occurring around ages 35-40, and a median survival of only 10 years after diagnosis, according to the FDA.

[email protected]

A rare, life-threatening anemia now has a new treatment option. The Food and Drug Administration announced the approval of pegcetacoplan (Empaveli) injection to treat adults with paroxysmal nocturnal hemoglobinuria (PNH). Pegcetacoplan is the first PNH treatment that binds to complement protein C3, according to the FDA announcement. Complement protein C3 is a key component of host immunity and defense.

Special concern

Because of the risk of severe side effects, the drug is available only through a restricted program under a risk evaluation and mitigation strategy (REMS). Serious infections can occur in patients taking pegcetacoplan that can become life-threatening or fatal if not treated early. According to the FDA, REMS are designed to reinforce medication use behaviors and actions that support the safe use of that medication, and only a few drugs require a REMS.

The most common other side effects are injection site reactions, diarrhea, abdominal pain, and fatigue.

Pegcetacoplan was approved based upon a study of 80 patients with PNH and anemia who had been taking eculizumab, a previously approved treatment. During 16 weeks of treatment, patients in the pegcetacoplan group had an average increase in their hemoglobin of 2.4 g/dL, while patients in the eculizumab group had an average decrease in their hemoglobin of 1.5 g/dL.
 

About the disease

PNH is caused by gene mutations that affect red blood cells, causing them to be defective and susceptible to destruction by a patient’s own immune system. Red blood cells in people with these mutations are defective and can be destroyed by the immune system, causing anemia.

Other symptoms include blood clots and destruction of bone marrow. The disease affects 1-1.5 people per million, with diagnosis typically occurring around ages 35-40, and a median survival of only 10 years after diagnosis, according to the FDA.

[email protected]

As individuals with sickle cell disease (SCD) are living longer than ever before there is a greater need to focus on maintaining and improving function and independence in this growing population. In the general population, impairments in functional measures such as usual gait speed, grip strength, Timed Up and Go, and cognition are associated with adverse health outcomes such as falls, fractures, loss of independence, and death.

Adults with SCD experience multiple complications such as avascular necrosis of the joints, retinopathy, and strokes that lead to functional limitations similar to those experienced by geriatric populations. However, functional assessments are not routinely performed during clinic visits with older adults with SCD.

In order to address this gap in care, my colleagues and I developed the first functional assessment for older adults with SCD, called the Sickle Cell Disease Functional Assessment (SCD-FA). This assessment will allow providers to evaluate the capabilities and vulnerabilities of older adults with SCD.

We assessed the feasibility of administering the SCD-FA in a prospective cohort pilot study. We enrolled 40 adults with SCD (20 older adults aged at least 50 years and 20 younger adults aged 18-49 years as a comparison group). All participants were assessed at steady-state.

For the SCD-FA, we selected geriatric assessment measures across seven domains: functional status, comorbid medical conditions, psychological state, social support, nutritional status, cognition, and medications. Several of these measures were previously validated in an oncology geriatric assessment and enriched with additional physical and cognitive measures to evaluate conditions at the intersection of SCD and geriatrics.

In September 2020, we published a protocol describing the methods and rationale for selecting measures for the SCD-FA in Pilot and Feasibility Studies.¹ The preliminary data was presented at the annual meeting of the American Society of Hematology in December 2020 and was included in the annual Hematology and Aging Poster Walk.

The results of this pilot study showed that the SCD-FA is feasible (91% of participants who consented completed the SCD-FA), acceptable (95% reported the length as appropriate and had no difficulty understanding the measures), and safe with no adverse events.² On physical performance testing, both younger and older participants had results consistent with accelerated aging with a functional age at least 20-30 years older than their chronological age.²

The majority of the participants (63%) had a usual gait speed slower than the speed required to safely cross the street at an intersection, and 25% had a gait speed slower than 1 m/s, which has been associated with increased mortality in the general population.^3,4
 

Benefits to management

The SCD-FA can improve management of adults with SCD by:

• Characterizing their capabilities and physiological age, identifying individuals at high risk for functional decline and death early identifying targets for interventions that have been successful in geriatrics,⁵ assessing risk of toxicity from curative therapies, and evaluating functional response to SCD-specific therapies.

The SCD-FA provides a framework for developing exercise interventions to target functional impairments. This work supports our goal of improving the quality of life and longevity for people with SCD.

Dr. Oyedeji is a senior hematology Fellow at the department of medicine, division of hematology, Duke University, Durham, N.C. She reported that she has no conflicts of interest.

References

1. Pilot Feasibility Stud. 2020;6:131.

2. Blood. 2020;136(Supplement 1):26-7.

3. J Rehabil Res Dev. 2005;42(4):535-46.

4. JAMA. 2011;305(1):50-8.

5. South Med J. 1994;87(5):S83-7.

As individuals with sickle cell disease (SCD) are living longer than ever before there is a greater need to focus on maintaining and improving function and independence in this growing population. In the general population, impairments in functional measures such as usual gait speed, grip strength, Timed Up and Go, and cognition are associated with adverse health outcomes such as falls, fractures, loss of independence, and death.

Adults with SCD experience multiple complications such as avascular necrosis of the joints, retinopathy, and strokes that lead to functional limitations similar to those experienced by geriatric populations. However, functional assessments are not routinely performed during clinic visits with older adults with SCD.

In order to address this gap in care, my colleagues and I developed the first functional assessment for older adults with SCD, called the Sickle Cell Disease Functional Assessment (SCD-FA). This assessment will allow providers to evaluate the capabilities and vulnerabilities of older adults with SCD.

We assessed the feasibility of administering the SCD-FA in a prospective cohort pilot study. We enrolled 40 adults with SCD (20 older adults aged at least 50 years and 20 younger adults aged 18-49 years as a comparison group). All participants were assessed at steady-state.

For the SCD-FA, we selected geriatric assessment measures across seven domains: functional status, comorbid medical conditions, psychological state, social support, nutritional status, cognition, and medications. Several of these measures were previously validated in an oncology geriatric assessment and enriched with additional physical and cognitive measures to evaluate conditions at the intersection of SCD and geriatrics.

In September 2020, we published a protocol describing the methods and rationale for selecting measures for the SCD-FA in Pilot and Feasibility Studies.¹ The preliminary data was presented at the annual meeting of the American Society of Hematology in December 2020 and was included in the annual Hematology and Aging Poster Walk.

The results of this pilot study showed that the SCD-FA is feasible (91% of participants who consented completed the SCD-FA), acceptable (95% reported the length as appropriate and had no difficulty understanding the measures), and safe with no adverse events.² On physical performance testing, both younger and older participants had results consistent with accelerated aging with a functional age at least 20-30 years older than their chronological age.²

The majority of the participants (63%) had a usual gait speed slower than the speed required to safely cross the street at an intersection, and 25% had a gait speed slower than 1 m/s, which has been associated with increased mortality in the general population.^3,4
 

Benefits to management

The SCD-FA can improve management of adults with SCD by:

• Characterizing their capabilities and physiological age, identifying individuals at high risk for functional decline and death early identifying targets for interventions that have been successful in geriatrics,⁵ assessing risk of toxicity from curative therapies, and evaluating functional response to SCD-specific therapies.

The SCD-FA provides a framework for developing exercise interventions to target functional impairments. This work supports our goal of improving the quality of life and longevity for people with SCD.

Dr. Oyedeji is a senior hematology Fellow at the department of medicine, division of hematology, Duke University, Durham, N.C. She reported that she has no conflicts of interest.

References

1. Pilot Feasibility Stud. 2020;6:131.

2. Blood. 2020;136(Supplement 1):26-7.

3. J Rehabil Res Dev. 2005;42(4):535-46.

4. JAMA. 2011;305(1):50-8.

5. South Med J. 1994;87(5):S83-7.

As individuals with sickle cell disease (SCD) are living longer than ever before there is a greater need to focus on maintaining and improving function and independence in this growing population. In the general population, impairments in functional measures such as usual gait speed, grip strength, Timed Up and Go, and cognition are associated with adverse health outcomes such as falls, fractures, loss of independence, and death.

Adults with SCD experience multiple complications such as avascular necrosis of the joints, retinopathy, and strokes that lead to functional limitations similar to those experienced by geriatric populations. However, functional assessments are not routinely performed during clinic visits with older adults with SCD.

In order to address this gap in care, my colleagues and I developed the first functional assessment for older adults with SCD, called the Sickle Cell Disease Functional Assessment (SCD-FA). This assessment will allow providers to evaluate the capabilities and vulnerabilities of older adults with SCD.

We assessed the feasibility of administering the SCD-FA in a prospective cohort pilot study. We enrolled 40 adults with SCD (20 older adults aged at least 50 years and 20 younger adults aged 18-49 years as a comparison group). All participants were assessed at steady-state.

For the SCD-FA, we selected geriatric assessment measures across seven domains: functional status, comorbid medical conditions, psychological state, social support, nutritional status, cognition, and medications. Several of these measures were previously validated in an oncology geriatric assessment and enriched with additional physical and cognitive measures to evaluate conditions at the intersection of SCD and geriatrics.

In September 2020, we published a protocol describing the methods and rationale for selecting measures for the SCD-FA in Pilot and Feasibility Studies.¹ The preliminary data was presented at the annual meeting of the American Society of Hematology in December 2020 and was included in the annual Hematology and Aging Poster Walk.

The results of this pilot study showed that the SCD-FA is feasible (91% of participants who consented completed the SCD-FA), acceptable (95% reported the length as appropriate and had no difficulty understanding the measures), and safe with no adverse events.² On physical performance testing, both younger and older participants had results consistent with accelerated aging with a functional age at least 20-30 years older than their chronological age.²

The majority of the participants (63%) had a usual gait speed slower than the speed required to safely cross the street at an intersection, and 25% had a gait speed slower than 1 m/s, which has been associated with increased mortality in the general population.^3,4
 

Benefits to management

The SCD-FA can improve management of adults with SCD by:

• Characterizing their capabilities and physiological age, identifying individuals at high risk for functional decline and death early identifying targets for interventions that have been successful in geriatrics,⁵ assessing risk of toxicity from curative therapies, and evaluating functional response to SCD-specific therapies.

The SCD-FA provides a framework for developing exercise interventions to target functional impairments. This work supports our goal of improving the quality of life and longevity for people with SCD.

Dr. Oyedeji is a senior hematology Fellow at the department of medicine, division of hematology, Duke University, Durham, N.C. She reported that she has no conflicts of interest.

References

1. Pilot Feasibility Stud. 2020;6:131.

2. Blood. 2020;136(Supplement 1):26-7.

3. J Rehabil Res Dev. 2005;42(4):535-46.

4. JAMA. 2011;305(1):50-8.

5. South Med J. 1994;87(5):S83-7.

Progress is being made in the quest for an oral treatment for sickle cell disease. In preclinical trials, a new drug has shown the ability to induce blood cells to produce fetal hemoglobin at levels predicted to prevent sickling. The new small-molecule drug could be formulated into a convenient daily oral dosage, according to researchers who presented their results at the spring meeting of the American Chemical Society, which was held virtually.

The new drug candidate, designated FTX-6058 by Fulcrum Therapeutics, was developed using a proprietary small-molecule probe and CRISPR guide RNA libraries to screen “a disease-relevant cell model that allowed us to pinpoint a treatment target,” said Ivan V. Efremov, PhD, senior director, head of medicinal chemistry at the company, who presented the research.

Even though sickle cell patients carry genes leading to defective adult hemoglobin, they still carry stem cells in their bone marrow with the potential to produce fetal hemoglobin. FTX-6058 attaches to a protein inside these bone marrow stem cells destined to become mature red blood cells and reinstates their fetal hemoglobin expression, according to Dr. Efremov.

“What is really key is FTX-6058 upregulates fetal hemoglobin across all red blood cells, a pancellular distribution,” he explained, adding that if “some red blood cells did not express this, they could still sickle and cause disease symptoms.”

The premise behind the development of the drug evolved from the example of patients with sickle cell genes who also have a mutation that causes fetal hemoglobin production. The presence of fetal hemoglobin provides significant benefits to patients with sickle cell disease. At around 5%-10% levels of fetal hemoglobin expression, mortality is reduced. By 10%-25% levels of fetal hemoglobin, recurring events including vaso-occlusive crises, acute chest syndrome, and hospitalization are reduced. When fetal hemoglobin levels reaches around 25%-30%, enough red blood cell function is restored so that these patients become asymptomatic, Dr. Efremov said.

FTX-6058 was designed to mimic this effect.

FTX-6058 inhibits the action of the polycomb repressive complex 2 (PRC2) via binding to the EED subunit. PRC2 acts as a histone methyltransferase to control gene expression. Inhibition of PRC2 leads to significant fetal hemoglobin protein expression in both cell and mouse models. Other such inhibitors are under study for the suppression of cancer progression.

Preclinical experiments comparing FTX-6058 with the fetal hemoglobin booster, hydroxyurea, approved in the 1990s, showed the new drug candidate outperforms the current treatment, Christopher Moxham, PhD, chief scientific officer of Fulcrum Therapeutics, said in a company press release. The company began a phase 1 safety trial in healthy adult volunteers last year after preclinical experiments with FTX-6058 in human-derived cell assay systems and mouse models also showed an increase in fetal hemoglobin to meet the 25%-30% asymptomatic symptom threshold level.
 

Ongoing studies

The researchers plan to launch phase 2 clinical trial enrolling patients with sickle cell disease by end of 2021. In addition, further characterization of the therapeutic molecule is continuing, using genomics and additional cell assay systems to expand details FTX-6058’s mode of action.

The company also is looking to explore the use of FTX-6058 in patients with beta-thalassemia to supplement their reduced hemoglobin production.

The pharmacologic profile of FTX-6058 indicates that the drug has the potential to be administered as a once-a-day oral formulation, Dr. Efremov stated. Both the preclinical PK [pharmacokinetic] data and “the emerging PK from the human clinical study supports once-a-day oral administration, which obviously offers significant convenience to patients,” he added.

Fulcrum Therapeutics is funding the studies.

[email protected]

Progress is being made in the quest for an oral treatment for sickle cell disease. In preclinical trials, a new drug has shown the ability to induce blood cells to produce fetal hemoglobin at levels predicted to prevent sickling. The new small-molecule drug could be formulated into a convenient daily oral dosage, according to researchers who presented their results at the spring meeting of the American Chemical Society, which was held virtually.

The new drug candidate, designated FTX-6058 by Fulcrum Therapeutics, was developed using a proprietary small-molecule probe and CRISPR guide RNA libraries to screen “a disease-relevant cell model that allowed us to pinpoint a treatment target,” said Ivan V. Efremov, PhD, senior director, head of medicinal chemistry at the company, who presented the research.

Even though sickle cell patients carry genes leading to defective adult hemoglobin, they still carry stem cells in their bone marrow with the potential to produce fetal hemoglobin. FTX-6058 attaches to a protein inside these bone marrow stem cells destined to become mature red blood cells and reinstates their fetal hemoglobin expression, according to Dr. Efremov.

“What is really key is FTX-6058 upregulates fetal hemoglobin across all red blood cells, a pancellular distribution,” he explained, adding that if “some red blood cells did not express this, they could still sickle and cause disease symptoms.”

The premise behind the development of the drug evolved from the example of patients with sickle cell genes who also have a mutation that causes fetal hemoglobin production. The presence of fetal hemoglobin provides significant benefits to patients with sickle cell disease. At around 5%-10% levels of fetal hemoglobin expression, mortality is reduced. By 10%-25% levels of fetal hemoglobin, recurring events including vaso-occlusive crises, acute chest syndrome, and hospitalization are reduced. When fetal hemoglobin levels reaches around 25%-30%, enough red blood cell function is restored so that these patients become asymptomatic, Dr. Efremov said.

FTX-6058 was designed to mimic this effect.

FTX-6058 inhibits the action of the polycomb repressive complex 2 (PRC2) via binding to the EED subunit. PRC2 acts as a histone methyltransferase to control gene expression. Inhibition of PRC2 leads to significant fetal hemoglobin protein expression in both cell and mouse models. Other such inhibitors are under study for the suppression of cancer progression.

Preclinical experiments comparing FTX-6058 with the fetal hemoglobin booster, hydroxyurea, approved in the 1990s, showed the new drug candidate outperforms the current treatment, Christopher Moxham, PhD, chief scientific officer of Fulcrum Therapeutics, said in a company press release. The company began a phase 1 safety trial in healthy adult volunteers last year after preclinical experiments with FTX-6058 in human-derived cell assay systems and mouse models also showed an increase in fetal hemoglobin to meet the 25%-30% asymptomatic symptom threshold level.
 

Ongoing studies

The researchers plan to launch phase 2 clinical trial enrolling patients with sickle cell disease by end of 2021. In addition, further characterization of the therapeutic molecule is continuing, using genomics and additional cell assay systems to expand details FTX-6058’s mode of action.

The company also is looking to explore the use of FTX-6058 in patients with beta-thalassemia to supplement their reduced hemoglobin production.

The pharmacologic profile of FTX-6058 indicates that the drug has the potential to be administered as a once-a-day oral formulation, Dr. Efremov stated. Both the preclinical PK [pharmacokinetic] data and “the emerging PK from the human clinical study supports once-a-day oral administration, which obviously offers significant convenience to patients,” he added.

Fulcrum Therapeutics is funding the studies.

[email protected]

Progress is being made in the quest for an oral treatment for sickle cell disease. In preclinical trials, a new drug has shown the ability to induce blood cells to produce fetal hemoglobin at levels predicted to prevent sickling. The new small-molecule drug could be formulated into a convenient daily oral dosage, according to researchers who presented their results at the spring meeting of the American Chemical Society, which was held virtually.

The new drug candidate, designated FTX-6058 by Fulcrum Therapeutics, was developed using a proprietary small-molecule probe and CRISPR guide RNA libraries to screen “a disease-relevant cell model that allowed us to pinpoint a treatment target,” said Ivan V. Efremov, PhD, senior director, head of medicinal chemistry at the company, who presented the research.

Even though sickle cell patients carry genes leading to defective adult hemoglobin, they still carry stem cells in their bone marrow with the potential to produce fetal hemoglobin. FTX-6058 attaches to a protein inside these bone marrow stem cells destined to become mature red blood cells and reinstates their fetal hemoglobin expression, according to Dr. Efremov.

“What is really key is FTX-6058 upregulates fetal hemoglobin across all red blood cells, a pancellular distribution,” he explained, adding that if “some red blood cells did not express this, they could still sickle and cause disease symptoms.”

The premise behind the development of the drug evolved from the example of patients with sickle cell genes who also have a mutation that causes fetal hemoglobin production. The presence of fetal hemoglobin provides significant benefits to patients with sickle cell disease. At around 5%-10% levels of fetal hemoglobin expression, mortality is reduced. By 10%-25% levels of fetal hemoglobin, recurring events including vaso-occlusive crises, acute chest syndrome, and hospitalization are reduced. When fetal hemoglobin levels reaches around 25%-30%, enough red blood cell function is restored so that these patients become asymptomatic, Dr. Efremov said.

FTX-6058 was designed to mimic this effect.

FTX-6058 inhibits the action of the polycomb repressive complex 2 (PRC2) via binding to the EED subunit. PRC2 acts as a histone methyltransferase to control gene expression. Inhibition of PRC2 leads to significant fetal hemoglobin protein expression in both cell and mouse models. Other such inhibitors are under study for the suppression of cancer progression.

Preclinical experiments comparing FTX-6058 with the fetal hemoglobin booster, hydroxyurea, approved in the 1990s, showed the new drug candidate outperforms the current treatment, Christopher Moxham, PhD, chief scientific officer of Fulcrum Therapeutics, said in a company press release. The company began a phase 1 safety trial in healthy adult volunteers last year after preclinical experiments with FTX-6058 in human-derived cell assay systems and mouse models also showed an increase in fetal hemoglobin to meet the 25%-30% asymptomatic symptom threshold level.
 

Ongoing studies

The researchers plan to launch phase 2 clinical trial enrolling patients with sickle cell disease by end of 2021. In addition, further characterization of the therapeutic molecule is continuing, using genomics and additional cell assay systems to expand details FTX-6058’s mode of action.

The company also is looking to explore the use of FTX-6058 in patients with beta-thalassemia to supplement their reduced hemoglobin production.

The pharmacologic profile of FTX-6058 indicates that the drug has the potential to be administered as a once-a-day oral formulation, Dr. Efremov stated. Both the preclinical PK [pharmacokinetic] data and “the emerging PK from the human clinical study supports once-a-day oral administration, which obviously offers significant convenience to patients,” he added.

Fulcrum Therapeutics is funding the studies.

[email protected]

Older men with a novel adult-onset, severe autoinflammatory syndrome known by the acronym VEXAS are likely hiding in plain sight in many adult rheumatology, hematology, and dermatology practices. New clinical features are being described to fill out the clinical profile of such patients who may be currently misdiagnosed with other conditions, according to researchers who first described the syndrome in the last quarter of 2020.

Courtesy Dr. Marcela Ferrada

VEXAS is often misdiagnosed as treatment-refractory relapsing polychondritis, polyarteritis nodosa, Sweet syndrome, or giant cell arteritis. These seemingly unrelated disorders are actually tied together by a single thread recently unraveled by David B. Beck, MD, PhD, a clinical fellow at the National Human Genome Research Institute, and colleagues, including rheumatologist Marcela Ferrada, MD, and others at institutes of the National Institutes of Health, Bethesda, Md. The connection between these disparate clinical presentations lies in somatic mutations in UBA1, a gene that initiates cytoplasmic ubiquitylation, a process by which misfolded proteins are tagged for degradation. VEXAS appears primarily limited to men because the UBA1 gene lies on the X chromosome, although it may be possible for women to have it because of an acquired loss of X chromosome.

VEXAS is an acronym for:

• Vacuoles in bone marrow cells
• E-1 activating enzyme, which is what UBA1 encodes for
• X-linked
• Autoinflammatory
• Somatic mutation featuring hematologic mosaicism

Dr. Beck said that VEXAS is “probably affecting thousands of Americans,” but it is tough to say this early in the understanding of the disease. He estimated that the prevalence of VEXAS could be 1 per 20,000-30,000 individuals.
 

A new way of looking for disease

VEXAS has caused a major stir among geneticists because of the novel manner in which Dr. Beck and his coinvestigators made their discovery. Instead of starting out in the traditional path to discovery of a new genetic disease – that is, by looking for clinical similarities among patients with undiagnosed diseases and then conducting a search for a gene or genes that might explain the shared patient symptoms – the investigators took a genotype-first approach. They scanned the mapped genomic sequences of patients in the National Institutes of Health Undiagnosed Diseases Network, which led them to zero in on mutations in UBA1 as their top candidate.

“We targeted the ubiquitin-proteasome pathway, because it has been implicated in many autoinflammatory diseases – for example, HA20 [A20 haploinsufficiency] and CANDLE syndrome [Chronic Atypical Neutrophilic Dermatosis with Lipodystrophy and Elevated temperature]. Many of these recurrent inflammatory diseases are caused by mutations within this pathway,” Dr. Beck said in an interview.

Next, they analyzed the genomes of patients in other NIH databases and patients from other study populations at the University College London and Leeds Teaching Hospitals NHS Trust in the United Kingdom in a search for UBA1 somatic mutations, eventually identifying 25 men with the shared features they called VEXAS. These 25 formed the basis for their initial report on the syndrome in the New England Journal of Medicine.

Most autoinflammatory diseases appear in childhood because they stem from germline mutations. VEXAS syndrome, because of somatic mutations with mosaicism, appears to manifest later in life: The median age of the initial 25-man cohort was 64 years, ranging from 45 to 80 years. It’s a severe disorder. By the time the investigators were preparing their paper for publication, 10 of the 25 patients, or 40%, had died.

“I think that somatic mutations may account for a significant percentage of severe. adult-onset rheumatologic diseases, and it may change the way we think about treating them based on having a genetic diagnosis,” Dr. Beck said.

“This approach could be expanded to look at other pathways we know are important in inflammation, or alternatively, it could be completely unbiased and look for any shared variation that occurs across undiagnosed patients with inflammatory diseases. I think that one thing that’s important about our study is that previously we had been looking for mutations that really in most cases were the same sort of germline mutations present in [pediatric] patients who have disease at early onset, but now we’re thinking about things differently. There may be a different type of genetics that drives adult-onset rheumatologic disease, and this would be somatic mutations which are not present in every cell of the body, just in the blood, and that’s why there’s just this blood-based disease.”
 

When to suspect VEXAS syndrome

Consider the possibility of VEXAS in middle-aged or older men in a rheumatology clinic with characteristics suggestive of treatment-refractory relapsing polychondritis, giant cell arteritis, polyarteritis nodosa, or Sweet syndrome. In the original series of 25 men, 15 were diagnosed with relapsing polychondritis, 8 with Sweet syndrome, 3 with polyarteritis nodosa, and 1 with giant cell arteritis.

Men with VEXAS often have periodic fevers, pulmonary infiltrates, a history of unprovoked venous thromboembolic events, neutrophilic dermatoses, and/or hematologic abnormalities such as myelodysplastic syndrome, multiple myeloma, or monoclonal gammopathy of unknown origin.

Dr. Katherine R. Calvo, M.D., Ph.D., NIH Clinical Center

Bone marrow biopsy will show vacuoles in myeloid and erythroid precursor cells. Inflammatory marker levels are very high: In the NIH series, the median C-reactive protein was 73 mg/L and median erythrocyte sedimentation rate was 97 mm/hr. The diagnosis of VEXAS can be confirmed by genetic testing performed by Dr. Beck and his NIH coworkers ([email protected]).

In interviews, Dr. Beck and Dr. Ferrada emphasized that management of VEXAS requires a multidisciplinary team of clinicians including rheumatologists, hematologists, and dermatologists.

Dr. Ferrada said that rheumatologists could suspect VEXAS in patients who have very high inflammatory markers and do not have a clear diagnosis or do not meet all criteria for other rheumatologic diseases, particularly in older men, but it’s possible in younger men as well. Hematologists could also consider VEXAS in patients with macrocytic anemia or macrocytosis without an explanation and inflammatory features, she said.

Dr. Ferrada, Dr. Beck, and colleagues also published a study in Arthritis & Rheumatology that presents a useful clinical algorithm for deciding whether to order genetic screening for VEXAS in patients with relapsing polychondritis.

First off, Dr. Ferrada and colleagues performed whole-exome sequencing and testing for UBA1 variants in an observational cohort of 92 relapsing polychondritis patients to determine the prevalence of VEXAS, which turned out to be 8%. They added an additional 6 patients with relapsing polychondritis and VEXAS from other cohorts, for a total of 13. The investigators determined that patients with VEXAS were older at disease onset, and more likely to have fever, ear chondritis, DVT, pulmonary infiltrates, skin involvement, and periorbital edema. In contrast, the RP cohort had a significantly higher prevalence of airway chondritis, joint involvement, and vestibular symptoms.

Courtesy Dr. Marcela Ferrada

Myelodysplastic syndrome and hematologic abnormalities

While patients with both myelodysplastic syndrome and relapsing polychondritis have been known in the literature for many years, it’s not until now that researchers are seeing a connection between the two, Dr. Ferrada said.

A majority of the VEXAS patients in the NEJM study had a workup for myelodysplastic syndrome, but only 24% met criteria. However, many were within the spectrum of myelodysplastic disease and some did not meet criteria because their anemia was attributed to a rheumatologic diagnosis and they did not have a known genetic driver of myelodysplastic syndrome, Dr. Beck said. It also fits with this new evidence that UBA1 is probably a driver of myelodysplastic syndrome in and of itself, and that anemia and hematologic involvement are not secondary to the rheumatologic disease; they are linked to the same disease process.

Dr. Beck said that there may be a subset of patients who present with primarily hematologic manifestations, noting the NEJM study could have ascertainment bias because the researchers analyzed mainly patients presenting to their clinic with relapsing polychondritis and severe inflammation. NIH researchers also are still looking in their cohort for any association with hematologic malignancies that preceded clinical manifestations, he said.
 

More cases reported

As of early April, another 27 cases had been reported in the literature as more researchers have begun to look for patients with UBA1 mutations, some with additional presenting clinical features associated with VEXAS, including chronic progressive inflammatory arthritis, Kikuchi-Fujimoto disease, spondyloarthritis, and bacterial pneumonia.

“Many times with rare diseases, we can’t get enough patients to understand the full spectrum of the disease, but this disease seems to be far more common than we would have expected. We’re actually getting many referrals,” Dr. Beck said.

It appears so far that the range of somatic UBA1 mutations that have been discovered in VEXAS patients does make a difference in the severity of clinical presentation and could potentially be useful in prognosis, Dr. Beck said.

Right now, NIH researchers are asking patients about their natural clinical course, assessing disease activity, and determining which treatments get a response, with the ultimate goal of a treatment trial at the NIH.

Treatment

Developing better treatments for VEXAS syndrome is a priority. In the initial report on VEXAS, the researchers found that the only reliably effective therapy is high-dose corticosteroids. Dr. Ferrada said that NIH investigators have begun thinking about agents that target both the hematologic and inflammatory features of VEXAS. “Most patients get exposed to treatments that are targeted to decrease the inflammatory process, and some of these treatments help partially but not completely to decrease the amount of steroids that patients are taking. For example, one of the medications is tocilizumab. [It was used in] patients who had previous diagnosis of relapsing polychondritis, but they still had to take steroids and their hematologic manifestations keep progressing. We’re in the process of figuring out medications that may help in treating both.” Dr. Ferrada added that because the source of the mutation is in the bone marrow, transplantation may be an effective option.

Laboratory work to identify potential treatments for VEXAS in studies of model organisms could identify treatments outside of the classic anti-inflammatory agents, such as targeting certain cell types in the bone marrow or the ubiquitin-proteasome pathway, Dr. Beck said. “We think that however UBA1 works to initiate inflammation may be important not just in VEXAS but in other diseases. Rare diseases may be informing the mechanisms in common diseases.”

The VEXAS NEJM study was sponsored by the NIH Intramural Research Programs and by an EU Horizon 2020 Research and Innovation Program grant. Dr. Beck reported a patent pending on “Diagnosis and Treatment of VEXAS with Mosaic Missense Mutations in UBA1.”

[email protected]

Older men with a novel adult-onset, severe autoinflammatory syndrome known by the acronym VEXAS are likely hiding in plain sight in many adult rheumatology, hematology, and dermatology practices. New clinical features are being described to fill out the clinical profile of such patients who may be currently misdiagnosed with other conditions, according to researchers who first described the syndrome in the last quarter of 2020.

Courtesy Dr. Marcela Ferrada

VEXAS is often misdiagnosed as treatment-refractory relapsing polychondritis, polyarteritis nodosa, Sweet syndrome, or giant cell arteritis. These seemingly unrelated disorders are actually tied together by a single thread recently unraveled by David B. Beck, MD, PhD, a clinical fellow at the National Human Genome Research Institute, and colleagues, including rheumatologist Marcela Ferrada, MD, and others at institutes of the National Institutes of Health, Bethesda, Md. The connection between these disparate clinical presentations lies in somatic mutations in UBA1, a gene that initiates cytoplasmic ubiquitylation, a process by which misfolded proteins are tagged for degradation. VEXAS appears primarily limited to men because the UBA1 gene lies on the X chromosome, although it may be possible for women to have it because of an acquired loss of X chromosome.

VEXAS is an acronym for:

• Vacuoles in bone marrow cells
• E-1 activating enzyme, which is what UBA1 encodes for
• X-linked
• Autoinflammatory
• Somatic mutation featuring hematologic mosaicism

Dr. Beck said that VEXAS is “probably affecting thousands of Americans,” but it is tough to say this early in the understanding of the disease. He estimated that the prevalence of VEXAS could be 1 per 20,000-30,000 individuals.
 

A new way of looking for disease

VEXAS has caused a major stir among geneticists because of the novel manner in which Dr. Beck and his coinvestigators made their discovery. Instead of starting out in the traditional path to discovery of a new genetic disease – that is, by looking for clinical similarities among patients with undiagnosed diseases and then conducting a search for a gene or genes that might explain the shared patient symptoms – the investigators took a genotype-first approach. They scanned the mapped genomic sequences of patients in the National Institutes of Health Undiagnosed Diseases Network, which led them to zero in on mutations in UBA1 as their top candidate.

“We targeted the ubiquitin-proteasome pathway, because it has been implicated in many autoinflammatory diseases – for example, HA20 [A20 haploinsufficiency] and CANDLE syndrome [Chronic Atypical Neutrophilic Dermatosis with Lipodystrophy and Elevated temperature]. Many of these recurrent inflammatory diseases are caused by mutations within this pathway,” Dr. Beck said in an interview.

Next, they analyzed the genomes of patients in other NIH databases and patients from other study populations at the University College London and Leeds Teaching Hospitals NHS Trust in the United Kingdom in a search for UBA1 somatic mutations, eventually identifying 25 men with the shared features they called VEXAS. These 25 formed the basis for their initial report on the syndrome in the New England Journal of Medicine.

Most autoinflammatory diseases appear in childhood because they stem from germline mutations. VEXAS syndrome, because of somatic mutations with mosaicism, appears to manifest later in life: The median age of the initial 25-man cohort was 64 years, ranging from 45 to 80 years. It’s a severe disorder. By the time the investigators were preparing their paper for publication, 10 of the 25 patients, or 40%, had died.

“I think that somatic mutations may account for a significant percentage of severe. adult-onset rheumatologic diseases, and it may change the way we think about treating them based on having a genetic diagnosis,” Dr. Beck said.

“This approach could be expanded to look at other pathways we know are important in inflammation, or alternatively, it could be completely unbiased and look for any shared variation that occurs across undiagnosed patients with inflammatory diseases. I think that one thing that’s important about our study is that previously we had been looking for mutations that really in most cases were the same sort of germline mutations present in [pediatric] patients who have disease at early onset, but now we’re thinking about things differently. There may be a different type of genetics that drives adult-onset rheumatologic disease, and this would be somatic mutations which are not present in every cell of the body, just in the blood, and that’s why there’s just this blood-based disease.”
 

When to suspect VEXAS syndrome

Consider the possibility of VEXAS in middle-aged or older men in a rheumatology clinic with characteristics suggestive of treatment-refractory relapsing polychondritis, giant cell arteritis, polyarteritis nodosa, or Sweet syndrome. In the original series of 25 men, 15 were diagnosed with relapsing polychondritis, 8 with Sweet syndrome, 3 with polyarteritis nodosa, and 1 with giant cell arteritis.

Men with VEXAS often have periodic fevers, pulmonary infiltrates, a history of unprovoked venous thromboembolic events, neutrophilic dermatoses, and/or hematologic abnormalities such as myelodysplastic syndrome, multiple myeloma, or monoclonal gammopathy of unknown origin.

Dr. Katherine R. Calvo, M.D., Ph.D., NIH Clinical Center

Bone marrow biopsy will show vacuoles in myeloid and erythroid precursor cells. Inflammatory marker levels are very high: In the NIH series, the median C-reactive protein was 73 mg/L and median erythrocyte sedimentation rate was 97 mm/hr. The diagnosis of VEXAS can be confirmed by genetic testing performed by Dr. Beck and his NIH coworkers ([email protected]).

In interviews, Dr. Beck and Dr. Ferrada emphasized that management of VEXAS requires a multidisciplinary team of clinicians including rheumatologists, hematologists, and dermatologists.

Dr. Ferrada said that rheumatologists could suspect VEXAS in patients who have very high inflammatory markers and do not have a clear diagnosis or do not meet all criteria for other rheumatologic diseases, particularly in older men, but it’s possible in younger men as well. Hematologists could also consider VEXAS in patients with macrocytic anemia or macrocytosis without an explanation and inflammatory features, she said.

Dr. Ferrada, Dr. Beck, and colleagues also published a study in Arthritis & Rheumatology that presents a useful clinical algorithm for deciding whether to order genetic screening for VEXAS in patients with relapsing polychondritis.

First off, Dr. Ferrada and colleagues performed whole-exome sequencing and testing for UBA1 variants in an observational cohort of 92 relapsing polychondritis patients to determine the prevalence of VEXAS, which turned out to be 8%. They added an additional 6 patients with relapsing polychondritis and VEXAS from other cohorts, for a total of 13. The investigators determined that patients with VEXAS were older at disease onset, and more likely to have fever, ear chondritis, DVT, pulmonary infiltrates, skin involvement, and periorbital edema. In contrast, the RP cohort had a significantly higher prevalence of airway chondritis, joint involvement, and vestibular symptoms.

Courtesy Dr. Marcela Ferrada

Myelodysplastic syndrome and hematologic abnormalities

While patients with both myelodysplastic syndrome and relapsing polychondritis have been known in the literature for many years, it’s not until now that researchers are seeing a connection between the two, Dr. Ferrada said.

A majority of the VEXAS patients in the NEJM study had a workup for myelodysplastic syndrome, but only 24% met criteria. However, many were within the spectrum of myelodysplastic disease and some did not meet criteria because their anemia was attributed to a rheumatologic diagnosis and they did not have a known genetic driver of myelodysplastic syndrome, Dr. Beck said. It also fits with this new evidence that UBA1 is probably a driver of myelodysplastic syndrome in and of itself, and that anemia and hematologic involvement are not secondary to the rheumatologic disease; they are linked to the same disease process.

Dr. Beck said that there may be a subset of patients who present with primarily hematologic manifestations, noting the NEJM study could have ascertainment bias because the researchers analyzed mainly patients presenting to their clinic with relapsing polychondritis and severe inflammation. NIH researchers also are still looking in their cohort for any association with hematologic malignancies that preceded clinical manifestations, he said.
 

More cases reported

As of early April, another 27 cases had been reported in the literature as more researchers have begun to look for patients with UBA1 mutations, some with additional presenting clinical features associated with VEXAS, including chronic progressive inflammatory arthritis, Kikuchi-Fujimoto disease, spondyloarthritis, and bacterial pneumonia.

“Many times with rare diseases, we can’t get enough patients to understand the full spectrum of the disease, but this disease seems to be far more common than we would have expected. We’re actually getting many referrals,” Dr. Beck said.

It appears so far that the range of somatic UBA1 mutations that have been discovered in VEXAS patients does make a difference in the severity of clinical presentation and could potentially be useful in prognosis, Dr. Beck said.

Right now, NIH researchers are asking patients about their natural clinical course, assessing disease activity, and determining which treatments get a response, with the ultimate goal of a treatment trial at the NIH.

Treatment

Developing better treatments for VEXAS syndrome is a priority. In the initial report on VEXAS, the researchers found that the only reliably effective therapy is high-dose corticosteroids. Dr. Ferrada said that NIH investigators have begun thinking about agents that target both the hematologic and inflammatory features of VEXAS. “Most patients get exposed to treatments that are targeted to decrease the inflammatory process, and some of these treatments help partially but not completely to decrease the amount of steroids that patients are taking. For example, one of the medications is tocilizumab. [It was used in] patients who had previous diagnosis of relapsing polychondritis, but they still had to take steroids and their hematologic manifestations keep progressing. We’re in the process of figuring out medications that may help in treating both.” Dr. Ferrada added that because the source of the mutation is in the bone marrow, transplantation may be an effective option.

Laboratory work to identify potential treatments for VEXAS in studies of model organisms could identify treatments outside of the classic anti-inflammatory agents, such as targeting certain cell types in the bone marrow or the ubiquitin-proteasome pathway, Dr. Beck said. “We think that however UBA1 works to initiate inflammation may be important not just in VEXAS but in other diseases. Rare diseases may be informing the mechanisms in common diseases.”

The VEXAS NEJM study was sponsored by the NIH Intramural Research Programs and by an EU Horizon 2020 Research and Innovation Program grant. Dr. Beck reported a patent pending on “Diagnosis and Treatment of VEXAS with Mosaic Missense Mutations in UBA1.”

[email protected]

Older men with a novel adult-onset, severe autoinflammatory syndrome known by the acronym VEXAS are likely hiding in plain sight in many adult rheumatology, hematology, and dermatology practices. New clinical features are being described to fill out the clinical profile of such patients who may be currently misdiagnosed with other conditions, according to researchers who first described the syndrome in the last quarter of 2020.

Courtesy Dr. Marcela Ferrada

VEXAS is often misdiagnosed as treatment-refractory relapsing polychondritis, polyarteritis nodosa, Sweet syndrome, or giant cell arteritis. These seemingly unrelated disorders are actually tied together by a single thread recently unraveled by David B. Beck, MD, PhD, a clinical fellow at the National Human Genome Research Institute, and colleagues, including rheumatologist Marcela Ferrada, MD, and others at institutes of the National Institutes of Health, Bethesda, Md. The connection between these disparate clinical presentations lies in somatic mutations in UBA1, a gene that initiates cytoplasmic ubiquitylation, a process by which misfolded proteins are tagged for degradation. VEXAS appears primarily limited to men because the UBA1 gene lies on the X chromosome, although it may be possible for women to have it because of an acquired loss of X chromosome.

VEXAS is an acronym for:

• Vacuoles in bone marrow cells
• E-1 activating enzyme, which is what UBA1 encodes for
• X-linked
• Autoinflammatory
• Somatic mutation featuring hematologic mosaicism

Dr. Beck said that VEXAS is “probably affecting thousands of Americans,” but it is tough to say this early in the understanding of the disease. He estimated that the prevalence of VEXAS could be 1 per 20,000-30,000 individuals.
 

A new way of looking for disease

VEXAS has caused a major stir among geneticists because of the novel manner in which Dr. Beck and his coinvestigators made their discovery. Instead of starting out in the traditional path to discovery of a new genetic disease – that is, by looking for clinical similarities among patients with undiagnosed diseases and then conducting a search for a gene or genes that might explain the shared patient symptoms – the investigators took a genotype-first approach. They scanned the mapped genomic sequences of patients in the National Institutes of Health Undiagnosed Diseases Network, which led them to zero in on mutations in UBA1 as their top candidate.

“We targeted the ubiquitin-proteasome pathway, because it has been implicated in many autoinflammatory diseases – for example, HA20 [A20 haploinsufficiency] and CANDLE syndrome [Chronic Atypical Neutrophilic Dermatosis with Lipodystrophy and Elevated temperature]. Many of these recurrent inflammatory diseases are caused by mutations within this pathway,” Dr. Beck said in an interview.

Next, they analyzed the genomes of patients in other NIH databases and patients from other study populations at the University College London and Leeds Teaching Hospitals NHS Trust in the United Kingdom in a search for UBA1 somatic mutations, eventually identifying 25 men with the shared features they called VEXAS. These 25 formed the basis for their initial report on the syndrome in the New England Journal of Medicine.

Most autoinflammatory diseases appear in childhood because they stem from germline mutations. VEXAS syndrome, because of somatic mutations with mosaicism, appears to manifest later in life: The median age of the initial 25-man cohort was 64 years, ranging from 45 to 80 years. It’s a severe disorder. By the time the investigators were preparing their paper for publication, 10 of the 25 patients, or 40%, had died.

“I think that somatic mutations may account for a significant percentage of severe. adult-onset rheumatologic diseases, and it may change the way we think about treating them based on having a genetic diagnosis,” Dr. Beck said.

“This approach could be expanded to look at other pathways we know are important in inflammation, or alternatively, it could be completely unbiased and look for any shared variation that occurs across undiagnosed patients with inflammatory diseases. I think that one thing that’s important about our study is that previously we had been looking for mutations that really in most cases were the same sort of germline mutations present in [pediatric] patients who have disease at early onset, but now we’re thinking about things differently. There may be a different type of genetics that drives adult-onset rheumatologic disease, and this would be somatic mutations which are not present in every cell of the body, just in the blood, and that’s why there’s just this blood-based disease.”
 

When to suspect VEXAS syndrome

Consider the possibility of VEXAS in middle-aged or older men in a rheumatology clinic with characteristics suggestive of treatment-refractory relapsing polychondritis, giant cell arteritis, polyarteritis nodosa, or Sweet syndrome. In the original series of 25 men, 15 were diagnosed with relapsing polychondritis, 8 with Sweet syndrome, 3 with polyarteritis nodosa, and 1 with giant cell arteritis.

Men with VEXAS often have periodic fevers, pulmonary infiltrates, a history of unprovoked venous thromboembolic events, neutrophilic dermatoses, and/or hematologic abnormalities such as myelodysplastic syndrome, multiple myeloma, or monoclonal gammopathy of unknown origin.

Dr. Katherine R. Calvo, M.D., Ph.D., NIH Clinical Center

Bone marrow biopsy will show vacuoles in myeloid and erythroid precursor cells. Inflammatory marker levels are very high: In the NIH series, the median C-reactive protein was 73 mg/L and median erythrocyte sedimentation rate was 97 mm/hr. The diagnosis of VEXAS can be confirmed by genetic testing performed by Dr. Beck and his NIH coworkers ([email protected]).

In interviews, Dr. Beck and Dr. Ferrada emphasized that management of VEXAS requires a multidisciplinary team of clinicians including rheumatologists, hematologists, and dermatologists.

Dr. Ferrada said that rheumatologists could suspect VEXAS in patients who have very high inflammatory markers and do not have a clear diagnosis or do not meet all criteria for other rheumatologic diseases, particularly in older men, but it’s possible in younger men as well. Hematologists could also consider VEXAS in patients with macrocytic anemia or macrocytosis without an explanation and inflammatory features, she said.

Dr. Ferrada, Dr. Beck, and colleagues also published a study in Arthritis & Rheumatology that presents a useful clinical algorithm for deciding whether to order genetic screening for VEXAS in patients with relapsing polychondritis.

First off, Dr. Ferrada and colleagues performed whole-exome sequencing and testing for UBA1 variants in an observational cohort of 92 relapsing polychondritis patients to determine the prevalence of VEXAS, which turned out to be 8%. They added an additional 6 patients with relapsing polychondritis and VEXAS from other cohorts, for a total of 13. The investigators determined that patients with VEXAS were older at disease onset, and more likely to have fever, ear chondritis, DVT, pulmonary infiltrates, skin involvement, and periorbital edema. In contrast, the RP cohort had a significantly higher prevalence of airway chondritis, joint involvement, and vestibular symptoms.

Courtesy Dr. Marcela Ferrada

Myelodysplastic syndrome and hematologic abnormalities

While patients with both myelodysplastic syndrome and relapsing polychondritis have been known in the literature for many years, it’s not until now that researchers are seeing a connection between the two, Dr. Ferrada said.

A majority of the VEXAS patients in the NEJM study had a workup for myelodysplastic syndrome, but only 24% met criteria. However, many were within the spectrum of myelodysplastic disease and some did not meet criteria because their anemia was attributed to a rheumatologic diagnosis and they did not have a known genetic driver of myelodysplastic syndrome, Dr. Beck said. It also fits with this new evidence that UBA1 is probably a driver of myelodysplastic syndrome in and of itself, and that anemia and hematologic involvement are not secondary to the rheumatologic disease; they are linked to the same disease process.

Dr. Beck said that there may be a subset of patients who present with primarily hematologic manifestations, noting the NEJM study could have ascertainment bias because the researchers analyzed mainly patients presenting to their clinic with relapsing polychondritis and severe inflammation. NIH researchers also are still looking in their cohort for any association with hematologic malignancies that preceded clinical manifestations, he said.
 

More cases reported

As of early April, another 27 cases had been reported in the literature as more researchers have begun to look for patients with UBA1 mutations, some with additional presenting clinical features associated with VEXAS, including chronic progressive inflammatory arthritis, Kikuchi-Fujimoto disease, spondyloarthritis, and bacterial pneumonia.

“Many times with rare diseases, we can’t get enough patients to understand the full spectrum of the disease, but this disease seems to be far more common than we would have expected. We’re actually getting many referrals,” Dr. Beck said.

It appears so far that the range of somatic UBA1 mutations that have been discovered in VEXAS patients does make a difference in the severity of clinical presentation and could potentially be useful in prognosis, Dr. Beck said.

Right now, NIH researchers are asking patients about their natural clinical course, assessing disease activity, and determining which treatments get a response, with the ultimate goal of a treatment trial at the NIH.

Treatment

Developing better treatments for VEXAS syndrome is a priority. In the initial report on VEXAS, the researchers found that the only reliably effective therapy is high-dose corticosteroids. Dr. Ferrada said that NIH investigators have begun thinking about agents that target both the hematologic and inflammatory features of VEXAS. “Most patients get exposed to treatments that are targeted to decrease the inflammatory process, and some of these treatments help partially but not completely to decrease the amount of steroids that patients are taking. For example, one of the medications is tocilizumab. [It was used in] patients who had previous diagnosis of relapsing polychondritis, but they still had to take steroids and their hematologic manifestations keep progressing. We’re in the process of figuring out medications that may help in treating both.” Dr. Ferrada added that because the source of the mutation is in the bone marrow, transplantation may be an effective option.

Laboratory work to identify potential treatments for VEXAS in studies of model organisms could identify treatments outside of the classic anti-inflammatory agents, such as targeting certain cell types in the bone marrow or the ubiquitin-proteasome pathway, Dr. Beck said. “We think that however UBA1 works to initiate inflammation may be important not just in VEXAS but in other diseases. Rare diseases may be informing the mechanisms in common diseases.”

The VEXAS NEJM study was sponsored by the NIH Intramural Research Programs and by an EU Horizon 2020 Research and Innovation Program grant. Dr. Beck reported a patent pending on “Diagnosis and Treatment of VEXAS with Mosaic Missense Mutations in UBA1.”

[email protected]

The Food and Drug Administration placed a clinical hold yesterday on two gene therapy trials for sickle cell disease (SCD) after two recent complications: one participant developed acute myeloid leukemia (AML) and another developed myelodysplastic syndrome (MDS). The sponsoring company, bluebird bio, suspended the trials last week upon learning of the cases.

The company has also put the brakes on a treatment for beta thalassemia already approved in the European Union and the United Kingdom, betibeglogene autotemcel (Zynteglo). The treatment hasn’t been associated with problems but uses the same gene delivery vector, a lentivirus, as that used in the SCD trials.

Overall, the company has enrolled 47 SCD patients and 63 with beta thalassemia in trials.

The gene therapy “space” is one with spectacular successes – for a form of retinal blindness and spinal muscular atrophy – rising against a backdrop of recent setbacks and failures – for Duchenne muscular dystrophy, lipoprotein lipase deficiency, and myotubular myopathy.
 

A lentiviral vector

The retooled lentivirus used in the SCD trials, LentiGlobin, delivers a beta-globin gene with one amino acid replacement to hematopoietic stem cells outside the patient’s body. The modified cells are then infused back into the patient. The gene therapy reshapes red blood cells, enabling them to circulate through narrow blood vessels without sickling and adhering into painful logjams.

What is worrisome is that in the patient who developed AML, and who received the gene therapy more than 5 years ago, the cancer cells contained the vector. Those test results aren’t yet available for the participant who has MDS.

The finding raises suspicion that the gene therapy had a role in the cancer, but is only correlative.

Lentiviral vectors have a good track record, but the two cases evoke memories of 2 decades ago. In 2001, five children being treated for an inherited immunodeficiency (SCID-X1) with a gamma retroviral vector developed leukemia and one died. Those viruses inserted into an oncogene. Happening 2 years after the death of 18-year-old Jesse Gelsinger in another gene therapy trial, the SCID trial had a chilling effect on the field.

Since then, lentiviral vectors have been reinvented to be “self-inactivating,” minimizing the risk for inserting willy-nilly into a genome. “Lentiviral vectors have been expressly designed to avoid insertional oncogenesis, based on prior experience with the gamma retroviruses. We don’t have evidence that the vector is causative, but our studies will shed some light on whether that’s true in these cases,” said bluebird bio chief scientific officer Philip Gregory, DPhil, on a conference call Feb. 16.

Lentiviral vectors have been successful as the backbone of chimeric antigen receptor T-cell (CAR-T) therapy, which directs modified T cells to certain blood cancers. “Among the hundreds to thousands of patients treated with CAR-T cell therapy, lentivirus vector hasn’t been associated with any malignancies,” said bluebird’s chief medical officer, Dave Davidson, MD.

Jeanne Loring, PhD, director of the Center for Regenerative Medicine at Scripps Research, agreed. “Gene therapy is having some extreme highs and lows these days. Most studies use [adeno-associated viral] vectors, which don’t integrate into the genome. But some people have antibodies to AAV vectors, and AAV is diluted out when cells divide. That’s why lentivirus, which integrates into the genome, is used for blood stem cells and T cells in CAR-T therapy.”
 

Pinpointing causality

At bluebird bio, investigation into the possible “genetic gymnastics” of the lentivirus vector is focusing on where it integrates into the genome – whether it harpoons an oncogene like the gamma retroviral vectors, or affects genome stability, Dr. Gregory explained. To be causative, the affected gene must be a “driver” of the cancer, and not just a “passenger.”

Another suspect is busulfan, a drug used to “condition” the recipient’s bone marrow, making room for modified stem cells. “It’s possible that busulfan is the main problem, as it is a carcinogen unto itself,” said Paul Knoepfler, PhD, a stem cell researcher at the University of California, Davis.

In addition to the two more recent reports of complications, a third trial participant, who had participated in a phase 1/2 trial, developed MDS in 2018 and died of AML in July 2020. The cancer cells from that patient did not contain viral vectors and the MDS was attributed to busulfan conditioning.

Nick Leschly, chief of bluebird, pointed out the importance of clinical context in implicating the vector. Because SCD itself stresses the bone marrow, patients already face an increased risk of developing blood cancer, he said. “Now layer on other risks of the gene therapy. It’s challenging because we’re dealing with patients who have life expectancy in the mid 40s.” Previous treatments, such the antisickling drug hydroxyurea, may also contribute to patient vulnerability.
 

A patient’s view

SCD affects more than 100,000 people in the United States, and about 20 million globally. Charles Hough is one of them. He can attest to the severity of the disease as well as the promise of gene therapy

Mr. Hough was diagnosed at age 2, and endured the profound fatigue, pain crises, and even coma characteristic of severe cases. He cited his “rebirth” as Sept. 25, 2018, when he received his first modified stem cells at the National Institutes of Health. Mr. Hough told his story a year ago in a webinar for the National Organization for Rare Disorders. This news organization caught up with him in light of the clinical trial hold.

Although the preparative regimens for the gene therapy were tough, his sickle cell symptoms vanished after gene therapy. Even hearing about the current hold on the clinical trial, Mr. Hough doesn’t regret his participation.

“I had a lot of friends who passed because of the complications from sickle cell. I was always worried that I wouldn’t live to see the next day. Now I don’t have that stress hanging over my head and I feel like I can live a normal life. Becoming sickle cell free was my dream.”

A version of this article first appeared on Medscape.com.

The Food and Drug Administration placed a clinical hold yesterday on two gene therapy trials for sickle cell disease (SCD) after two recent complications: one participant developed acute myeloid leukemia (AML) and another developed myelodysplastic syndrome (MDS). The sponsoring company, bluebird bio, suspended the trials last week upon learning of the cases.

The company has also put the brakes on a treatment for beta thalassemia already approved in the European Union and the United Kingdom, betibeglogene autotemcel (Zynteglo). The treatment hasn’t been associated with problems but uses the same gene delivery vector, a lentivirus, as that used in the SCD trials.

Overall, the company has enrolled 47 SCD patients and 63 with beta thalassemia in trials.

The gene therapy “space” is one with spectacular successes – for a form of retinal blindness and spinal muscular atrophy – rising against a backdrop of recent setbacks and failures – for Duchenne muscular dystrophy, lipoprotein lipase deficiency, and myotubular myopathy.
 

A lentiviral vector

The retooled lentivirus used in the SCD trials, LentiGlobin, delivers a beta-globin gene with one amino acid replacement to hematopoietic stem cells outside the patient’s body. The modified cells are then infused back into the patient. The gene therapy reshapes red blood cells, enabling them to circulate through narrow blood vessels without sickling and adhering into painful logjams.

What is worrisome is that in the patient who developed AML, and who received the gene therapy more than 5 years ago, the cancer cells contained the vector. Those test results aren’t yet available for the participant who has MDS.

The finding raises suspicion that the gene therapy had a role in the cancer, but is only correlative.

Lentiviral vectors have a good track record, but the two cases evoke memories of 2 decades ago. In 2001, five children being treated for an inherited immunodeficiency (SCID-X1) with a gamma retroviral vector developed leukemia and one died. Those viruses inserted into an oncogene. Happening 2 years after the death of 18-year-old Jesse Gelsinger in another gene therapy trial, the SCID trial had a chilling effect on the field.

Since then, lentiviral vectors have been reinvented to be “self-inactivating,” minimizing the risk for inserting willy-nilly into a genome. “Lentiviral vectors have been expressly designed to avoid insertional oncogenesis, based on prior experience with the gamma retroviruses. We don’t have evidence that the vector is causative, but our studies will shed some light on whether that’s true in these cases,” said bluebird bio chief scientific officer Philip Gregory, DPhil, on a conference call Feb. 16.

Lentiviral vectors have been successful as the backbone of chimeric antigen receptor T-cell (CAR-T) therapy, which directs modified T cells to certain blood cancers. “Among the hundreds to thousands of patients treated with CAR-T cell therapy, lentivirus vector hasn’t been associated with any malignancies,” said bluebird’s chief medical officer, Dave Davidson, MD.

Jeanne Loring, PhD, director of the Center for Regenerative Medicine at Scripps Research, agreed. “Gene therapy is having some extreme highs and lows these days. Most studies use [adeno-associated viral] vectors, which don’t integrate into the genome. But some people have antibodies to AAV vectors, and AAV is diluted out when cells divide. That’s why lentivirus, which integrates into the genome, is used for blood stem cells and T cells in CAR-T therapy.”
 

Pinpointing causality

At bluebird bio, investigation into the possible “genetic gymnastics” of the lentivirus vector is focusing on where it integrates into the genome – whether it harpoons an oncogene like the gamma retroviral vectors, or affects genome stability, Dr. Gregory explained. To be causative, the affected gene must be a “driver” of the cancer, and not just a “passenger.”

Another suspect is busulfan, a drug used to “condition” the recipient’s bone marrow, making room for modified stem cells. “It’s possible that busulfan is the main problem, as it is a carcinogen unto itself,” said Paul Knoepfler, PhD, a stem cell researcher at the University of California, Davis.

In addition to the two more recent reports of complications, a third trial participant, who had participated in a phase 1/2 trial, developed MDS in 2018 and died of AML in July 2020. The cancer cells from that patient did not contain viral vectors and the MDS was attributed to busulfan conditioning.

Nick Leschly, chief of bluebird, pointed out the importance of clinical context in implicating the vector. Because SCD itself stresses the bone marrow, patients already face an increased risk of developing blood cancer, he said. “Now layer on other risks of the gene therapy. It’s challenging because we’re dealing with patients who have life expectancy in the mid 40s.” Previous treatments, such the antisickling drug hydroxyurea, may also contribute to patient vulnerability.
 

A patient’s view

SCD affects more than 100,000 people in the United States, and about 20 million globally. Charles Hough is one of them. He can attest to the severity of the disease as well as the promise of gene therapy

Mr. Hough was diagnosed at age 2, and endured the profound fatigue, pain crises, and even coma characteristic of severe cases. He cited his “rebirth” as Sept. 25, 2018, when he received his first modified stem cells at the National Institutes of Health. Mr. Hough told his story a year ago in a webinar for the National Organization for Rare Disorders. This news organization caught up with him in light of the clinical trial hold.

Although the preparative regimens for the gene therapy were tough, his sickle cell symptoms vanished after gene therapy. Even hearing about the current hold on the clinical trial, Mr. Hough doesn’t regret his participation.

“I had a lot of friends who passed because of the complications from sickle cell. I was always worried that I wouldn’t live to see the next day. Now I don’t have that stress hanging over my head and I feel like I can live a normal life. Becoming sickle cell free was my dream.”

A version of this article first appeared on Medscape.com.

The Food and Drug Administration placed a clinical hold yesterday on two gene therapy trials for sickle cell disease (SCD) after two recent complications: one participant developed acute myeloid leukemia (AML) and another developed myelodysplastic syndrome (MDS). The sponsoring company, bluebird bio, suspended the trials last week upon learning of the cases.

The company has also put the brakes on a treatment for beta thalassemia already approved in the European Union and the United Kingdom, betibeglogene autotemcel (Zynteglo). The treatment hasn’t been associated with problems but uses the same gene delivery vector, a lentivirus, as that used in the SCD trials.

Overall, the company has enrolled 47 SCD patients and 63 with beta thalassemia in trials.

The gene therapy “space” is one with spectacular successes – for a form of retinal blindness and spinal muscular atrophy – rising against a backdrop of recent setbacks and failures – for Duchenne muscular dystrophy, lipoprotein lipase deficiency, and myotubular myopathy.
 

A lentiviral vector

The retooled lentivirus used in the SCD trials, LentiGlobin, delivers a beta-globin gene with one amino acid replacement to hematopoietic stem cells outside the patient’s body. The modified cells are then infused back into the patient. The gene therapy reshapes red blood cells, enabling them to circulate through narrow blood vessels without sickling and adhering into painful logjams.

What is worrisome is that in the patient who developed AML, and who received the gene therapy more than 5 years ago, the cancer cells contained the vector. Those test results aren’t yet available for the participant who has MDS.

The finding raises suspicion that the gene therapy had a role in the cancer, but is only correlative.

Lentiviral vectors have a good track record, but the two cases evoke memories of 2 decades ago. In 2001, five children being treated for an inherited immunodeficiency (SCID-X1) with a gamma retroviral vector developed leukemia and one died. Those viruses inserted into an oncogene. Happening 2 years after the death of 18-year-old Jesse Gelsinger in another gene therapy trial, the SCID trial had a chilling effect on the field.

Since then, lentiviral vectors have been reinvented to be “self-inactivating,” minimizing the risk for inserting willy-nilly into a genome. “Lentiviral vectors have been expressly designed to avoid insertional oncogenesis, based on prior experience with the gamma retroviruses. We don’t have evidence that the vector is causative, but our studies will shed some light on whether that’s true in these cases,” said bluebird bio chief scientific officer Philip Gregory, DPhil, on a conference call Feb. 16.

Lentiviral vectors have been successful as the backbone of chimeric antigen receptor T-cell (CAR-T) therapy, which directs modified T cells to certain blood cancers. “Among the hundreds to thousands of patients treated with CAR-T cell therapy, lentivirus vector hasn’t been associated with any malignancies,” said bluebird’s chief medical officer, Dave Davidson, MD.

Jeanne Loring, PhD, director of the Center for Regenerative Medicine at Scripps Research, agreed. “Gene therapy is having some extreme highs and lows these days. Most studies use [adeno-associated viral] vectors, which don’t integrate into the genome. But some people have antibodies to AAV vectors, and AAV is diluted out when cells divide. That’s why lentivirus, which integrates into the genome, is used for blood stem cells and T cells in CAR-T therapy.”
 

Pinpointing causality

At bluebird bio, investigation into the possible “genetic gymnastics” of the lentivirus vector is focusing on where it integrates into the genome – whether it harpoons an oncogene like the gamma retroviral vectors, or affects genome stability, Dr. Gregory explained. To be causative, the affected gene must be a “driver” of the cancer, and not just a “passenger.”

Another suspect is busulfan, a drug used to “condition” the recipient’s bone marrow, making room for modified stem cells. “It’s possible that busulfan is the main problem, as it is a carcinogen unto itself,” said Paul Knoepfler, PhD, a stem cell researcher at the University of California, Davis.

In addition to the two more recent reports of complications, a third trial participant, who had participated in a phase 1/2 trial, developed MDS in 2018 and died of AML in July 2020. The cancer cells from that patient did not contain viral vectors and the MDS was attributed to busulfan conditioning.

Nick Leschly, chief of bluebird, pointed out the importance of clinical context in implicating the vector. Because SCD itself stresses the bone marrow, patients already face an increased risk of developing blood cancer, he said. “Now layer on other risks of the gene therapy. It’s challenging because we’re dealing with patients who have life expectancy in the mid 40s.” Previous treatments, such the antisickling drug hydroxyurea, may also contribute to patient vulnerability.
 

A patient’s view

SCD affects more than 100,000 people in the United States, and about 20 million globally. Charles Hough is one of them. He can attest to the severity of the disease as well as the promise of gene therapy

Mr. Hough was diagnosed at age 2, and endured the profound fatigue, pain crises, and even coma characteristic of severe cases. He cited his “rebirth” as Sept. 25, 2018, when he received his first modified stem cells at the National Institutes of Health. Mr. Hough told his story a year ago in a webinar for the National Organization for Rare Disorders. This news organization caught up with him in light of the clinical trial hold.

Although the preparative regimens for the gene therapy were tough, his sickle cell symptoms vanished after gene therapy. Even hearing about the current hold on the clinical trial, Mr. Hough doesn’t regret his participation.

“I had a lot of friends who passed because of the complications from sickle cell. I was always worried that I wouldn’t live to see the next day. Now I don’t have that stress hanging over my head and I feel like I can live a normal life. Becoming sickle cell free was my dream.”

A version of this article first appeared on Medscape.com.