AML

Photo from University of Texas Southwestern Medical Center

Efforts to determine why immune checkpoint blockade is not successful in treating leukemia have resulted in a “compelling” new target to treat monocytic acute myeloid leukemia (AML), according to researchers.

They discovered that leukocyte immunoglobulin-like receptor B4 (LILRB4), a marker of monocytic leukemia, creates an immunosuppressive microenvironment by mediating T-cell suppression.

Using a mouse model and human cells, the research team showed that LILRB4 supports tumor infiltration into tissues and suppresses T-cell activity through a signaling pathway involving APOE, LILRB4, SHP-2, uPAR, and ARG1.

Senior author Chengcheng “Alec” Zhang, PhD, of the University of Texas Southwestern Medical Center in Dallas, and his colleagues reported their findings in Nature.

The team first compared surface expression of LILRB4 on normal monocytes and neoplastic monocytes from 105 AML patient samples. They observed that LILRB4 levels were higher on monocytic AML cells than on normal monocytes.

The researchers then tested whether LILRB4 expressed on AML cells suppressed T cells. They cultured LILRB4-positive leukemia cells, LILRB4-negative leukemia cells, and normal hematopoietic cells with either autologous T cells or T cells from healthy donors. The team determined that only LILRB4-positive monocytic AML cells substantially suppressed T-cell proliferation.

When the researchers knocked out LILRB4, the ability of AML cells to suppress T cells was reduced and could be restored with forced expression of wild-type LILRB4. Additionally, LILRB4-mediated T-cell inhibition could be reversed by LILRB4-blocking antibodies.

The team then used a humanized mouse xenograft model and an immunocompetent mouse model to investigate LILRB4 function in immune checkpoint blockade. Blocking LILRB4 lowered tumor burden and prolonged survival in the mice.

The researchers performed numerous in vitro and in vivo experiments and observed that antibody blockade of LILRB4 shrank tumors and decreased leukemic infiltration into internal organs, including the bone marrow, liver, and brain.

And so the team hypothesized that LILRB4 promotes leukemia infiltration in addition to inhibiting T cells.

To test the hypothesis, they performed transendothelial migration and homing assays and monitored leukemia infiltration relative to LILRB4 expression on leukemia cells. They observed that LILRB4-mediated migration enhanced extramedullary infiltration of monocytic AML cells, thus contributing to immune evasion.

The researchers also found that APOE protein activated the immune inhibitory receptor LILRB4.

To ascertain whether suppression of T cells by LILRB4 depends on APOE, the team co-cultured T cells with control or human AML cells with APOE knocked out.

Through a series of experiments, they determined that APOE is an extracellular binding protein of LILRB4 and that APOE activates LILRB4 to support T-cell proliferation and AML cell migration.

The researchers believe that targeting LILRB4 may have minimal toxicity. This is because LILRB4 expression on normal monocytic cells is limited, LILRB4 signaling may differ in leukemia cells, and LILRB4 blockade did not significantly interfere with normal hematopoietic function.

Dr. Zhang anticipates that if the preclinical studies go well, clinical trials could begin as early as next year.

The University of Texas System has exclusively licensed LILRB4-related patent applications to California-based Immune-Onc Therapeutics Inc., which contributed to the research and is conducting preclinical studies.

Dr. Zhang and another author are scientific advisory board members with Immune-Onc Therapeutics. Two other authors are employees of and hold equities in Immune-Onc Therapeutics.

The researchers received additional funding for this work from the National Cancer Institute, Leukemia & Lymphoma Society, the March of Dimes, the Cancer Prevention and Research Institute of Texas, the Robert A. Welch Foundation, the National Natural Science Foundation of China, the National Basic Research Program of China, and the China Scholarship Council. 

Photo from University of Texas Southwestern Medical Center

Efforts to determine why immune checkpoint blockade is not successful in treating leukemia have resulted in a “compelling” new target to treat monocytic acute myeloid leukemia (AML), according to researchers.

They discovered that leukocyte immunoglobulin-like receptor B4 (LILRB4), a marker of monocytic leukemia, creates an immunosuppressive microenvironment by mediating T-cell suppression.

Using a mouse model and human cells, the research team showed that LILRB4 supports tumor infiltration into tissues and suppresses T-cell activity through a signaling pathway involving APOE, LILRB4, SHP-2, uPAR, and ARG1.

Senior author Chengcheng “Alec” Zhang, PhD, of the University of Texas Southwestern Medical Center in Dallas, and his colleagues reported their findings in Nature.

The team first compared surface expression of LILRB4 on normal monocytes and neoplastic monocytes from 105 AML patient samples. They observed that LILRB4 levels were higher on monocytic AML cells than on normal monocytes.

The researchers then tested whether LILRB4 expressed on AML cells suppressed T cells. They cultured LILRB4-positive leukemia cells, LILRB4-negative leukemia cells, and normal hematopoietic cells with either autologous T cells or T cells from healthy donors. The team determined that only LILRB4-positive monocytic AML cells substantially suppressed T-cell proliferation.

When the researchers knocked out LILRB4, the ability of AML cells to suppress T cells was reduced and could be restored with forced expression of wild-type LILRB4. Additionally, LILRB4-mediated T-cell inhibition could be reversed by LILRB4-blocking antibodies.

The team then used a humanized mouse xenograft model and an immunocompetent mouse model to investigate LILRB4 function in immune checkpoint blockade. Blocking LILRB4 lowered tumor burden and prolonged survival in the mice.

The researchers performed numerous in vitro and in vivo experiments and observed that antibody blockade of LILRB4 shrank tumors and decreased leukemic infiltration into internal organs, including the bone marrow, liver, and brain.

And so the team hypothesized that LILRB4 promotes leukemia infiltration in addition to inhibiting T cells.

To test the hypothesis, they performed transendothelial migration and homing assays and monitored leukemia infiltration relative to LILRB4 expression on leukemia cells. They observed that LILRB4-mediated migration enhanced extramedullary infiltration of monocytic AML cells, thus contributing to immune evasion.

The researchers also found that APOE protein activated the immune inhibitory receptor LILRB4.

To ascertain whether suppression of T cells by LILRB4 depends on APOE, the team co-cultured T cells with control or human AML cells with APOE knocked out.

Through a series of experiments, they determined that APOE is an extracellular binding protein of LILRB4 and that APOE activates LILRB4 to support T-cell proliferation and AML cell migration.

The researchers believe that targeting LILRB4 may have minimal toxicity. This is because LILRB4 expression on normal monocytic cells is limited, LILRB4 signaling may differ in leukemia cells, and LILRB4 blockade did not significantly interfere with normal hematopoietic function.

Dr. Zhang anticipates that if the preclinical studies go well, clinical trials could begin as early as next year.

The University of Texas System has exclusively licensed LILRB4-related patent applications to California-based Immune-Onc Therapeutics Inc., which contributed to the research and is conducting preclinical studies.

Dr. Zhang and another author are scientific advisory board members with Immune-Onc Therapeutics. Two other authors are employees of and hold equities in Immune-Onc Therapeutics.

The researchers received additional funding for this work from the National Cancer Institute, Leukemia & Lymphoma Society, the March of Dimes, the Cancer Prevention and Research Institute of Texas, the Robert A. Welch Foundation, the National Natural Science Foundation of China, the National Basic Research Program of China, and the China Scholarship Council. 

Photo from University of Texas Southwestern Medical Center

Efforts to determine why immune checkpoint blockade is not successful in treating leukemia have resulted in a “compelling” new target to treat monocytic acute myeloid leukemia (AML), according to researchers.

They discovered that leukocyte immunoglobulin-like receptor B4 (LILRB4), a marker of monocytic leukemia, creates an immunosuppressive microenvironment by mediating T-cell suppression.

Using a mouse model and human cells, the research team showed that LILRB4 supports tumor infiltration into tissues and suppresses T-cell activity through a signaling pathway involving APOE, LILRB4, SHP-2, uPAR, and ARG1.

Senior author Chengcheng “Alec” Zhang, PhD, of the University of Texas Southwestern Medical Center in Dallas, and his colleagues reported their findings in Nature.

The team first compared surface expression of LILRB4 on normal monocytes and neoplastic monocytes from 105 AML patient samples. They observed that LILRB4 levels were higher on monocytic AML cells than on normal monocytes.

The researchers then tested whether LILRB4 expressed on AML cells suppressed T cells. They cultured LILRB4-positive leukemia cells, LILRB4-negative leukemia cells, and normal hematopoietic cells with either autologous T cells or T cells from healthy donors. The team determined that only LILRB4-positive monocytic AML cells substantially suppressed T-cell proliferation.

When the researchers knocked out LILRB4, the ability of AML cells to suppress T cells was reduced and could be restored with forced expression of wild-type LILRB4. Additionally, LILRB4-mediated T-cell inhibition could be reversed by LILRB4-blocking antibodies.

The team then used a humanized mouse xenograft model and an immunocompetent mouse model to investigate LILRB4 function in immune checkpoint blockade. Blocking LILRB4 lowered tumor burden and prolonged survival in the mice.

The researchers performed numerous in vitro and in vivo experiments and observed that antibody blockade of LILRB4 shrank tumors and decreased leukemic infiltration into internal organs, including the bone marrow, liver, and brain.

And so the team hypothesized that LILRB4 promotes leukemia infiltration in addition to inhibiting T cells.

To test the hypothesis, they performed transendothelial migration and homing assays and monitored leukemia infiltration relative to LILRB4 expression on leukemia cells. They observed that LILRB4-mediated migration enhanced extramedullary infiltration of monocytic AML cells, thus contributing to immune evasion.

The researchers also found that APOE protein activated the immune inhibitory receptor LILRB4.

To ascertain whether suppression of T cells by LILRB4 depends on APOE, the team co-cultured T cells with control or human AML cells with APOE knocked out.

Through a series of experiments, they determined that APOE is an extracellular binding protein of LILRB4 and that APOE activates LILRB4 to support T-cell proliferation and AML cell migration.

The researchers believe that targeting LILRB4 may have minimal toxicity. This is because LILRB4 expression on normal monocytic cells is limited, LILRB4 signaling may differ in leukemia cells, and LILRB4 blockade did not significantly interfere with normal hematopoietic function.

Dr. Zhang anticipates that if the preclinical studies go well, clinical trials could begin as early as next year.

The University of Texas System has exclusively licensed LILRB4-related patent applications to California-based Immune-Onc Therapeutics Inc., which contributed to the research and is conducting preclinical studies.

Dr. Zhang and another author are scientific advisory board members with Immune-Onc Therapeutics. Two other authors are employees of and hold equities in Immune-Onc Therapeutics.

The researchers received additional funding for this work from the National Cancer Institute, Leukemia & Lymphoma Society, the March of Dimes, the Cancer Prevention and Research Institute of Texas, the Robert A. Welch Foundation, the National Natural Science Foundation of China, the National Basic Research Program of China, and the China Scholarship Council. 

MD Anderson Cancer Center

The combination of azacitidine and nivolumab produced “encouraging” results in a phase 2 trial of patients with relapsed or refractory acute myeloid leukemia (AML), according to researchers.

The overall response rate was 33%, and the median overall survival (OS) was 6.3 months.

However, the researchers identified factors associated with improved response and survival that they believe could be used to select patients for this treatment.

A quarter of patients on this trial had immune-related adverse events (AEs) that were considered related to treatment, and two patients died of AEs that may have been treatment-related.

Naval Daver, MD, of The University of Texas MD Anderson Cancer Center in Houston, and his colleagues reported these results in Cancer Discovery.

The trial included 70 patients with a median age of 70 (range, 22-90). Fifty-six percent had de novo AML, and 44% had secondary AML.

The median number of prior therapies was 2 (range, 1 to 7). Sixty-four percent of patients had received hypomethylating agents, 47% had received targeted therapies, and 19% had received allogeneic stem cell transplant (SCT).

For this trial, patients received azacitidine at 75 mg/m² on days 1 to 7 and nivolumab at 3 mg/kg on days 1 and 14 of each cycle. The median number of cycles was 3 (range, 1 to 25).

Patients had a median time on study of 3.5 months (range, 0.3 to 26.3 months). Reasons for discontinuation included primary refractory disease (n=27), relapse after initial response (n=19), death (n=16), proceeding to SCT (n=3), and patient preference (n=3).

Safety

The most common treatment-related, non-hematologic AEs were constipation (26%), diarrhea (20%), pneumonitis (13%), nausea (11%), and lung infection (11%).

The rate of immune-related AEs was 25% (n=18), with grade 2-4 immune-related AEs occurring in 16 patients (8 with grade 3-4). Fourteen of these patients responded to steroids and were safely re-challenged with nivolumab, according to the researchers.

Nine patients (13%) discontinued nivolumab (but continued with azacitidine) due to AEs—pneumonitis (n=7), cytokine release syndrome (n=1), and immune nephritis (n=1).

Two patients died of AEs that were considered possibly related to treatment. One death was due to progressive pneumonia/pneumonitis, and one was due to hemophagocytosis lymphohistiocytosis.

Response

The overall response rate was 33% (n=23). Four patients had a complete response (CR), and 11 had a CR with incomplete count recovery (CRi).

One patient had a partial response, and seven had hematologic improvement in one or more parameter maintained for more than 6 months. Six patients had stable disease lasting more than 6 months.

The researchers noted that the response rate was higher among patients who had not received prior treatment with hypomethylating agents. In addition, a higher frequency of pre-therapy CD3 and CD8 cells in the bone marrow or peripheral blood appeared to predict response.

“In particular, CD3 appeared to have a high sensitivity and specificity rate for predicting response, indicating it might serve as a reliable biomarker for selecting patients for this combination therapy,” Dr. Daver said.

Survival

At a median follow-up of 21.4 months, 81% of patients (n=57) had died. Sixteen patients died on study treatment, and 41 died after discontinuation.

The median OS was 6.3 months, and the median event-free survival was 4.5 months.

The median OS was 16.1 months in patients with CR/CRi,  partial response, hematologic improvement, or stable disease and 4.1 months in non-responders (P<0.0001). This difference was still significant after the researchers censored the three patients who had gone on to SCT in CR/CRi (P<0.001).

The researchers also found that being in first salvage was associated with improved OS in a univariate analysis and in a comparison with historical controls.

Dr. Daver and his colleagues concluded that azacitidine and nivolumab “produced an encouraging response rate and overall survival” in patients with relapsed/refractory AML.

“We believe that implementation of clinical and immune biomarkers to select patients are likely to yield further improved outcomes with these types of therapies in AML,” Dr. Daver noted.

This research was supported by Bristol-Myers Squibb, MD Anderson, and the Dick Clark Immunotherapy Research Fund. In addition, individual researchers reported financial relationships with Bristol-Myers Squibb.

MD Anderson Cancer Center

The combination of azacitidine and nivolumab produced “encouraging” results in a phase 2 trial of patients with relapsed or refractory acute myeloid leukemia (AML), according to researchers.

The overall response rate was 33%, and the median overall survival (OS) was 6.3 months.

However, the researchers identified factors associated with improved response and survival that they believe could be used to select patients for this treatment.

A quarter of patients on this trial had immune-related adverse events (AEs) that were considered related to treatment, and two patients died of AEs that may have been treatment-related.

Naval Daver, MD, of The University of Texas MD Anderson Cancer Center in Houston, and his colleagues reported these results in Cancer Discovery.

The trial included 70 patients with a median age of 70 (range, 22-90). Fifty-six percent had de novo AML, and 44% had secondary AML.

The median number of prior therapies was 2 (range, 1 to 7). Sixty-four percent of patients had received hypomethylating agents, 47% had received targeted therapies, and 19% had received allogeneic stem cell transplant (SCT).

For this trial, patients received azacitidine at 75 mg/m² on days 1 to 7 and nivolumab at 3 mg/kg on days 1 and 14 of each cycle. The median number of cycles was 3 (range, 1 to 25).

Patients had a median time on study of 3.5 months (range, 0.3 to 26.3 months). Reasons for discontinuation included primary refractory disease (n=27), relapse after initial response (n=19), death (n=16), proceeding to SCT (n=3), and patient preference (n=3).

Safety

The most common treatment-related, non-hematologic AEs were constipation (26%), diarrhea (20%), pneumonitis (13%), nausea (11%), and lung infection (11%).

The rate of immune-related AEs was 25% (n=18), with grade 2-4 immune-related AEs occurring in 16 patients (8 with grade 3-4). Fourteen of these patients responded to steroids and were safely re-challenged with nivolumab, according to the researchers.

Nine patients (13%) discontinued nivolumab (but continued with azacitidine) due to AEs—pneumonitis (n=7), cytokine release syndrome (n=1), and immune nephritis (n=1).

Two patients died of AEs that were considered possibly related to treatment. One death was due to progressive pneumonia/pneumonitis, and one was due to hemophagocytosis lymphohistiocytosis.

Response

The overall response rate was 33% (n=23). Four patients had a complete response (CR), and 11 had a CR with incomplete count recovery (CRi).

One patient had a partial response, and seven had hematologic improvement in one or more parameter maintained for more than 6 months. Six patients had stable disease lasting more than 6 months.

The researchers noted that the response rate was higher among patients who had not received prior treatment with hypomethylating agents. In addition, a higher frequency of pre-therapy CD3 and CD8 cells in the bone marrow or peripheral blood appeared to predict response.

“In particular, CD3 appeared to have a high sensitivity and specificity rate for predicting response, indicating it might serve as a reliable biomarker for selecting patients for this combination therapy,” Dr. Daver said.

Survival

At a median follow-up of 21.4 months, 81% of patients (n=57) had died. Sixteen patients died on study treatment, and 41 died after discontinuation.

The median OS was 6.3 months, and the median event-free survival was 4.5 months.

The median OS was 16.1 months in patients with CR/CRi,  partial response, hematologic improvement, or stable disease and 4.1 months in non-responders (P<0.0001). This difference was still significant after the researchers censored the three patients who had gone on to SCT in CR/CRi (P<0.001).

The researchers also found that being in first salvage was associated with improved OS in a univariate analysis and in a comparison with historical controls.

Dr. Daver and his colleagues concluded that azacitidine and nivolumab “produced an encouraging response rate and overall survival” in patients with relapsed/refractory AML.

“We believe that implementation of clinical and immune biomarkers to select patients are likely to yield further improved outcomes with these types of therapies in AML,” Dr. Daver noted.

This research was supported by Bristol-Myers Squibb, MD Anderson, and the Dick Clark Immunotherapy Research Fund. In addition, individual researchers reported financial relationships with Bristol-Myers Squibb.

MD Anderson Cancer Center

The combination of azacitidine and nivolumab produced “encouraging” results in a phase 2 trial of patients with relapsed or refractory acute myeloid leukemia (AML), according to researchers.

The overall response rate was 33%, and the median overall survival (OS) was 6.3 months.

However, the researchers identified factors associated with improved response and survival that they believe could be used to select patients for this treatment.

A quarter of patients on this trial had immune-related adverse events (AEs) that were considered related to treatment, and two patients died of AEs that may have been treatment-related.

Naval Daver, MD, of The University of Texas MD Anderson Cancer Center in Houston, and his colleagues reported these results in Cancer Discovery.

The trial included 70 patients with a median age of 70 (range, 22-90). Fifty-six percent had de novo AML, and 44% had secondary AML.

The median number of prior therapies was 2 (range, 1 to 7). Sixty-four percent of patients had received hypomethylating agents, 47% had received targeted therapies, and 19% had received allogeneic stem cell transplant (SCT).

For this trial, patients received azacitidine at 75 mg/m² on days 1 to 7 and nivolumab at 3 mg/kg on days 1 and 14 of each cycle. The median number of cycles was 3 (range, 1 to 25).

Patients had a median time on study of 3.5 months (range, 0.3 to 26.3 months). Reasons for discontinuation included primary refractory disease (n=27), relapse after initial response (n=19), death (n=16), proceeding to SCT (n=3), and patient preference (n=3).

Safety

The most common treatment-related, non-hematologic AEs were constipation (26%), diarrhea (20%), pneumonitis (13%), nausea (11%), and lung infection (11%).

The rate of immune-related AEs was 25% (n=18), with grade 2-4 immune-related AEs occurring in 16 patients (8 with grade 3-4). Fourteen of these patients responded to steroids and were safely re-challenged with nivolumab, according to the researchers.

Nine patients (13%) discontinued nivolumab (but continued with azacitidine) due to AEs—pneumonitis (n=7), cytokine release syndrome (n=1), and immune nephritis (n=1).

Two patients died of AEs that were considered possibly related to treatment. One death was due to progressive pneumonia/pneumonitis, and one was due to hemophagocytosis lymphohistiocytosis.

Response

The overall response rate was 33% (n=23). Four patients had a complete response (CR), and 11 had a CR with incomplete count recovery (CRi).

One patient had a partial response, and seven had hematologic improvement in one or more parameter maintained for more than 6 months. Six patients had stable disease lasting more than 6 months.

The researchers noted that the response rate was higher among patients who had not received prior treatment with hypomethylating agents. In addition, a higher frequency of pre-therapy CD3 and CD8 cells in the bone marrow or peripheral blood appeared to predict response.

“In particular, CD3 appeared to have a high sensitivity and specificity rate for predicting response, indicating it might serve as a reliable biomarker for selecting patients for this combination therapy,” Dr. Daver said.

Survival

At a median follow-up of 21.4 months, 81% of patients (n=57) had died. Sixteen patients died on study treatment, and 41 died after discontinuation.

The median OS was 6.3 months, and the median event-free survival was 4.5 months.

The median OS was 16.1 months in patients with CR/CRi,  partial response, hematologic improvement, or stable disease and 4.1 months in non-responders (P<0.0001). This difference was still significant after the researchers censored the three patients who had gone on to SCT in CR/CRi (P<0.001).

The researchers also found that being in first salvage was associated with improved OS in a univariate analysis and in a comparison with historical controls.

Dr. Daver and his colleagues concluded that azacitidine and nivolumab “produced an encouraging response rate and overall survival” in patients with relapsed/refractory AML.

“We believe that implementation of clinical and immune biomarkers to select patients are likely to yield further improved outcomes with these types of therapies in AML,” Dr. Daver noted.

This research was supported by Bristol-Myers Squibb, MD Anderson, and the Dick Clark Immunotherapy Research Fund. In addition, individual researchers reported financial relationships with Bristol-Myers Squibb.

Allowed costs for patients with blood cancer averaged almost $157,000 in the year after diagnosis, with costs for acute leukemia almost tripling that amount, according to a new report from the Leukemia & Lymphoma Society (LLS).

Total allowed cost – the average amount paid by the insurer and patient combined – for acute leukemia was more than $463,000 for the 12 months after initial diagnosis. Averages for the other four cancers included in the analysis came in at $214,000 for multiple myeloma, $134,000 for bone marrow disorders, $131,000 for lymphoma, and $89,000 for chronic leukemia, the LLS said.

The cost figures are drawn from claims data for 2,332 patients diagnosed in 2014.

Differences in out-of-pocket (OOP) costs were smaller, with the average for all patients at almost $3,900 in the year after diagnosis and acute leukemia coming in the highest at $5,100. Over time, however, OOP costs for multiple myeloma patients became the highest, totaling $9,100 for the 3 years after diagnosis, compared with $8,800 for acute leukemia and an average of less than $7,800 for the other blood cancers, the LLS said in the report, which was prepared by the actuarial firm Milliman.

OOP costs also varied by the type of plan. Patients in high-deductible plans averaged nearly $5,400 for the first year after diagnosis, compared with $3,300 for those with traditional insurance, the LLS noted. For acute leukemia, the OOP costs of high-deductible plans were more than twice as high as those of traditional plans.

The study was based on data for adults aged 18-64 years from the Truven Health MarketScan commercial claims databases for the years from 2013 to 2016. The LLS received support for the study from Pfizer, Genentech, and Amgen.
 

[email protected]

Allowed costs for patients with blood cancer averaged almost $157,000 in the year after diagnosis, with costs for acute leukemia almost tripling that amount, according to a new report from the Leukemia & Lymphoma Society (LLS).

Total allowed cost – the average amount paid by the insurer and patient combined – for acute leukemia was more than $463,000 for the 12 months after initial diagnosis. Averages for the other four cancers included in the analysis came in at $214,000 for multiple myeloma, $134,000 for bone marrow disorders, $131,000 for lymphoma, and $89,000 for chronic leukemia, the LLS said.

The cost figures are drawn from claims data for 2,332 patients diagnosed in 2014.

Differences in out-of-pocket (OOP) costs were smaller, with the average for all patients at almost $3,900 in the year after diagnosis and acute leukemia coming in the highest at $5,100. Over time, however, OOP costs for multiple myeloma patients became the highest, totaling $9,100 for the 3 years after diagnosis, compared with $8,800 for acute leukemia and an average of less than $7,800 for the other blood cancers, the LLS said in the report, which was prepared by the actuarial firm Milliman.

OOP costs also varied by the type of plan. Patients in high-deductible plans averaged nearly $5,400 for the first year after diagnosis, compared with $3,300 for those with traditional insurance, the LLS noted. For acute leukemia, the OOP costs of high-deductible plans were more than twice as high as those of traditional plans.

The study was based on data for adults aged 18-64 years from the Truven Health MarketScan commercial claims databases for the years from 2013 to 2016. The LLS received support for the study from Pfizer, Genentech, and Amgen.
 

[email protected]

Allowed costs for patients with blood cancer averaged almost $157,000 in the year after diagnosis, with costs for acute leukemia almost tripling that amount, according to a new report from the Leukemia & Lymphoma Society (LLS).

Total allowed cost – the average amount paid by the insurer and patient combined – for acute leukemia was more than $463,000 for the 12 months after initial diagnosis. Averages for the other four cancers included in the analysis came in at $214,000 for multiple myeloma, $134,000 for bone marrow disorders, $131,000 for lymphoma, and $89,000 for chronic leukemia, the LLS said.

The cost figures are drawn from claims data for 2,332 patients diagnosed in 2014.

Differences in out-of-pocket (OOP) costs were smaller, with the average for all patients at almost $3,900 in the year after diagnosis and acute leukemia coming in the highest at $5,100. Over time, however, OOP costs for multiple myeloma patients became the highest, totaling $9,100 for the 3 years after diagnosis, compared with $8,800 for acute leukemia and an average of less than $7,800 for the other blood cancers, the LLS said in the report, which was prepared by the actuarial firm Milliman.

OOP costs also varied by the type of plan. Patients in high-deductible plans averaged nearly $5,400 for the first year after diagnosis, compared with $3,300 for those with traditional insurance, the LLS noted. For acute leukemia, the OOP costs of high-deductible plans were more than twice as high as those of traditional plans.

The study was based on data for adults aged 18-64 years from the Truven Health MarketScan commercial claims databases for the years from 2013 to 2016. The LLS received support for the study from Pfizer, Genentech, and Amgen.
 

[email protected]

Henrique Orlandi Mourao

The European Medicines Agency has granted accelerated assessment to the marketing authorization application (MAA) for the FLT3 inhibitor quizartinib.

With this MAA, Daiichi Sankyo Company, Ltd., is seeking authorization for quizartinib to treat adults with FLT3-ITD-positive, relapsed or refractory acute myeloid leukemia (AML).

Accelerated assessment is given to products expected to be of major interest for public health and therapeutic innovation, and it can reduce the review timeline from 210 days to 150 days.

Quizartinib also has orphan drug designation from the European Commission.

The MAA for quizartinib is based on the phase 3 QuANTUM-R study. Results from this trial were presented at the 23rd Congress of the European Hematology Association in June.

QuANTUM-R enrolled adults with FLT3-ITD AML (at least 3% FLT3-ITD allelic ratio) who had refractory disease or had relapsed within 6 months of their first complete response (CR).

Patients were randomized to receive once-daily treatment with quizartinib (n=245) or a salvage chemotherapy regimen (n=122)—low-dose cytarabine (LoDAC, n=29); combination mitoxantrone, etoposide, and cytarabine (MEC, n=40); or combination fludarabine, cytarabine, and idarubicin (FLAG-IDA, n=53).

Patients who responded to treatment could proceed to hematopoietic stem cell transplant (HSCT), and those in the quizartinib arm could resume quizartinib after HSCT.

In all, 241 patients received quizartinib, and 94 received salvage chemotherapy—LoDAC (n=22), MEC (n=25), and FLAG-IDA (n=47). Of the 28 patients in the chemotherapy group who were not treated, most withdrew consent.

Thirty-two percent of quizartinib-treated patients and 12% of the chemotherapy group went on to HSCT.

Efficacy

The median follow-up was 23.5 months. The efficacy results include all randomized patients.

The overall response rate was 69% in the quizartinib arm and 30% in the chemotherapy arm.

The composite CR rate was 48% in the quizartinib arm and 27% in the chemotherapy arm. This includes:

• The CR rate (4% and 1%, respectively)
• The rate of CR with incomplete platelet recovery (4% and 0%, respectively)
• The rate of CR with incomplete hematologic recovery (40% and 26%, respectively).

The median event-free survival was 6.0 weeks in the quizartinib arm and 3.7 weeks in the chemotherapy arm (hazard ratio=0.90, P=0.1071).

The median overall survival was 6.2 months in the quizartinib arm and 4.7 months in the chemotherapy arm (hazard ratio=0.76, P=0.0177). The 1-year overall survival rate was 27% and 20%, respectively.

Safety

The safety results include only patients who received their assigned treatment.

Grade 3 or higher hematologic treatment-emergent adverse events occurring in at least 5% of patients (in the quizartinib and chemotherapy groups, respectively) included:

• Thrombocytopenia (35% and 34%)
• Anemia (30% and 29%)
• Neutropenia (32% and 25%)
• Febrile neutropenia (31% and 21%)
• Leukopenia (17% and 16%).

Grade 3 or higher non-hematologic treatment-emergent adverse events occurring in at least 5% of patients (in the quizartinib and chemotherapy groups, respectively) included:

• Sepsis/septic shock (16% and 18%)
• Hypokalemia (12% and 9%)
• Pneumonia (12% and 9%)
• Fatigue (8% and 1%)
• Dyspnea (5% for both)
• Hypophosphatemia (5% for both).

Henrique Orlandi Mourao

The European Medicines Agency has granted accelerated assessment to the marketing authorization application (MAA) for the FLT3 inhibitor quizartinib.

With this MAA, Daiichi Sankyo Company, Ltd., is seeking authorization for quizartinib to treat adults with FLT3-ITD-positive, relapsed or refractory acute myeloid leukemia (AML).

Accelerated assessment is given to products expected to be of major interest for public health and therapeutic innovation, and it can reduce the review timeline from 210 days to 150 days.

Quizartinib also has orphan drug designation from the European Commission.

The MAA for quizartinib is based on the phase 3 QuANTUM-R study. Results from this trial were presented at the 23rd Congress of the European Hematology Association in June.

QuANTUM-R enrolled adults with FLT3-ITD AML (at least 3% FLT3-ITD allelic ratio) who had refractory disease or had relapsed within 6 months of their first complete response (CR).

Patients were randomized to receive once-daily treatment with quizartinib (n=245) or a salvage chemotherapy regimen (n=122)—low-dose cytarabine (LoDAC, n=29); combination mitoxantrone, etoposide, and cytarabine (MEC, n=40); or combination fludarabine, cytarabine, and idarubicin (FLAG-IDA, n=53).

Patients who responded to treatment could proceed to hematopoietic stem cell transplant (HSCT), and those in the quizartinib arm could resume quizartinib after HSCT.

In all, 241 patients received quizartinib, and 94 received salvage chemotherapy—LoDAC (n=22), MEC (n=25), and FLAG-IDA (n=47). Of the 28 patients in the chemotherapy group who were not treated, most withdrew consent.

Thirty-two percent of quizartinib-treated patients and 12% of the chemotherapy group went on to HSCT.

Efficacy

The median follow-up was 23.5 months. The efficacy results include all randomized patients.

The overall response rate was 69% in the quizartinib arm and 30% in the chemotherapy arm.

The composite CR rate was 48% in the quizartinib arm and 27% in the chemotherapy arm. This includes:

• The CR rate (4% and 1%, respectively)
• The rate of CR with incomplete platelet recovery (4% and 0%, respectively)
• The rate of CR with incomplete hematologic recovery (40% and 26%, respectively).

The median event-free survival was 6.0 weeks in the quizartinib arm and 3.7 weeks in the chemotherapy arm (hazard ratio=0.90, P=0.1071).

The median overall survival was 6.2 months in the quizartinib arm and 4.7 months in the chemotherapy arm (hazard ratio=0.76, P=0.0177). The 1-year overall survival rate was 27% and 20%, respectively.

Safety

The safety results include only patients who received their assigned treatment.

Grade 3 or higher hematologic treatment-emergent adverse events occurring in at least 5% of patients (in the quizartinib and chemotherapy groups, respectively) included:

• Thrombocytopenia (35% and 34%)
• Anemia (30% and 29%)
• Neutropenia (32% and 25%)
• Febrile neutropenia (31% and 21%)
• Leukopenia (17% and 16%).

Grade 3 or higher non-hematologic treatment-emergent adverse events occurring in at least 5% of patients (in the quizartinib and chemotherapy groups, respectively) included:

• Sepsis/septic shock (16% and 18%)
• Hypokalemia (12% and 9%)
• Pneumonia (12% and 9%)
• Fatigue (8% and 1%)
• Dyspnea (5% for both)
• Hypophosphatemia (5% for both).

Henrique Orlandi Mourao

The European Medicines Agency has granted accelerated assessment to the marketing authorization application (MAA) for the FLT3 inhibitor quizartinib.

With this MAA, Daiichi Sankyo Company, Ltd., is seeking authorization for quizartinib to treat adults with FLT3-ITD-positive, relapsed or refractory acute myeloid leukemia (AML).

Accelerated assessment is given to products expected to be of major interest for public health and therapeutic innovation, and it can reduce the review timeline from 210 days to 150 days.

Quizartinib also has orphan drug designation from the European Commission.

The MAA for quizartinib is based on the phase 3 QuANTUM-R study. Results from this trial were presented at the 23rd Congress of the European Hematology Association in June.

QuANTUM-R enrolled adults with FLT3-ITD AML (at least 3% FLT3-ITD allelic ratio) who had refractory disease or had relapsed within 6 months of their first complete response (CR).

Patients were randomized to receive once-daily treatment with quizartinib (n=245) or a salvage chemotherapy regimen (n=122)—low-dose cytarabine (LoDAC, n=29); combination mitoxantrone, etoposide, and cytarabine (MEC, n=40); or combination fludarabine, cytarabine, and idarubicin (FLAG-IDA, n=53).

Patients who responded to treatment could proceed to hematopoietic stem cell transplant (HSCT), and those in the quizartinib arm could resume quizartinib after HSCT.

In all, 241 patients received quizartinib, and 94 received salvage chemotherapy—LoDAC (n=22), MEC (n=25), and FLAG-IDA (n=47). Of the 28 patients in the chemotherapy group who were not treated, most withdrew consent.

Thirty-two percent of quizartinib-treated patients and 12% of the chemotherapy group went on to HSCT.

Efficacy

The median follow-up was 23.5 months. The efficacy results include all randomized patients.

The overall response rate was 69% in the quizartinib arm and 30% in the chemotherapy arm.

The composite CR rate was 48% in the quizartinib arm and 27% in the chemotherapy arm. This includes:

• The CR rate (4% and 1%, respectively)
• The rate of CR with incomplete platelet recovery (4% and 0%, respectively)
• The rate of CR with incomplete hematologic recovery (40% and 26%, respectively).

The median event-free survival was 6.0 weeks in the quizartinib arm and 3.7 weeks in the chemotherapy arm (hazard ratio=0.90, P=0.1071).

The median overall survival was 6.2 months in the quizartinib arm and 4.7 months in the chemotherapy arm (hazard ratio=0.76, P=0.0177). The 1-year overall survival rate was 27% and 20%, respectively.

Safety

The safety results include only patients who received their assigned treatment.

Grade 3 or higher hematologic treatment-emergent adverse events occurring in at least 5% of patients (in the quizartinib and chemotherapy groups, respectively) included:

• Thrombocytopenia (35% and 34%)
• Anemia (30% and 29%)
• Neutropenia (32% and 25%)
• Febrile neutropenia (31% and 21%)
• Leukopenia (17% and 16%).

Grade 3 or higher non-hematologic treatment-emergent adverse events occurring in at least 5% of patients (in the quizartinib and chemotherapy groups, respectively) included:

• Sepsis/septic shock (16% and 18%)
• Hypokalemia (12% and 9%)
• Pneumonia (12% and 9%)
• Fatigue (8% and 1%)
• Dyspnea (5% for both)
• Hypophosphatemia (5% for both).

AML cells

New research suggests relapse of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplant (HSCT) is related to changes in immune-related gene expression that may be reversible.

Researchers observed downregulation of major histocompatibility complex (MHC) class II genes in samples from patients who relapsed after HSCT.

However, interferon-gamma “rapidly reversed this phenotype” in vitro, according to the researchers.

Matthew J. Christopher, MD, PhD, of Washington University School of Medicine in St. Louis, Missouri, and his colleagues reported these findings in The New England Journal of Medicine.

The researchers set out to determine how genetic and epigenetic changes after HSCT may allow leukemic cells to avoid the graft-vs-leukemia effect and to see whether immune-related genes are affected by HSCT.

The team analyzed paired samples obtained at diagnosis and relapse from 15 AML patients who relapsed after HSCT and 20 AML patients who relapsed after chemotherapy. The team also analyzed additional samples from patients who relapsed after HSCT to validate initial findings.

Methods of analysis included enhanced exome sequencing, RNA sequencing, flow cytometry, and immunohistochemical analysis.

Findings

The researchers first looked for relapse-specific mutations but found no driver mutations associated with relapse after HSCT.

The mutations seen post-HSCT relapse were generally similar to those seen both before treatment and after relapse in patients who had undergone chemotherapy, and the researchers could not identify any patterns of mutations related to relapse.

They then looked for, but did not find, relapse-specific mutations in genes involved in modulation of immune checkpoints, antigen presentation, or cytokine signaling.

The researchers did, however, find evidence of epigenetic changes that were more common in the samples from patients with post-transplant relapses.

RNA sequencing showed that MHC class II genes (HLA-DPA1, HLA-DPB1, HLA-DQB1, and HLA-DRB1) were downregulated three- to 12-fold after transplant.

Flow cytometry and immunohistochemical analysis confirmed that MHC class II expression was decreased at relapse after HSCT in 17 of 34 samples evaluated.

The researchers said there was no association between the downregulation of MHC class II and donor type or use of immunosuppression.

To see whether the downregulation of MHC class II genes was reversible, the researchers treated three post-HSCT relapse samples with interferon-gamma, which is known to upregulate MHC class II on certain cells.

Culturing patient cells with interferon-gamma “rapidly induced MHC class II protein expression on leukemic blasts,” the researchers said. They observed “essentially full restoration of MHC class II protein expression in nearly all AML blasts after 72 hours.”

This study was supported by the National Institutes of Health, Leukemia and Lymphoma Society, and the Barnes-Jewish Hospital Foundation.

Several study authors reported personal fees and/or research support from industry outside the submitted work.

AML cells

New research suggests relapse of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplant (HSCT) is related to changes in immune-related gene expression that may be reversible.

Researchers observed downregulation of major histocompatibility complex (MHC) class II genes in samples from patients who relapsed after HSCT.

However, interferon-gamma “rapidly reversed this phenotype” in vitro, according to the researchers.

Matthew J. Christopher, MD, PhD, of Washington University School of Medicine in St. Louis, Missouri, and his colleagues reported these findings in The New England Journal of Medicine.

The researchers set out to determine how genetic and epigenetic changes after HSCT may allow leukemic cells to avoid the graft-vs-leukemia effect and to see whether immune-related genes are affected by HSCT.

The team analyzed paired samples obtained at diagnosis and relapse from 15 AML patients who relapsed after HSCT and 20 AML patients who relapsed after chemotherapy. The team also analyzed additional samples from patients who relapsed after HSCT to validate initial findings.

Methods of analysis included enhanced exome sequencing, RNA sequencing, flow cytometry, and immunohistochemical analysis.

Findings

The researchers first looked for relapse-specific mutations but found no driver mutations associated with relapse after HSCT.

The mutations seen post-HSCT relapse were generally similar to those seen both before treatment and after relapse in patients who had undergone chemotherapy, and the researchers could not identify any patterns of mutations related to relapse.

They then looked for, but did not find, relapse-specific mutations in genes involved in modulation of immune checkpoints, antigen presentation, or cytokine signaling.

The researchers did, however, find evidence of epigenetic changes that were more common in the samples from patients with post-transplant relapses.

RNA sequencing showed that MHC class II genes (HLA-DPA1, HLA-DPB1, HLA-DQB1, and HLA-DRB1) were downregulated three- to 12-fold after transplant.

Flow cytometry and immunohistochemical analysis confirmed that MHC class II expression was decreased at relapse after HSCT in 17 of 34 samples evaluated.

The researchers said there was no association between the downregulation of MHC class II and donor type or use of immunosuppression.

To see whether the downregulation of MHC class II genes was reversible, the researchers treated three post-HSCT relapse samples with interferon-gamma, which is known to upregulate MHC class II on certain cells.

Culturing patient cells with interferon-gamma “rapidly induced MHC class II protein expression on leukemic blasts,” the researchers said. They observed “essentially full restoration of MHC class II protein expression in nearly all AML blasts after 72 hours.”

This study was supported by the National Institutes of Health, Leukemia and Lymphoma Society, and the Barnes-Jewish Hospital Foundation.

Several study authors reported personal fees and/or research support from industry outside the submitted work.

AML cells

New research suggests relapse of acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplant (HSCT) is related to changes in immune-related gene expression that may be reversible.

Researchers observed downregulation of major histocompatibility complex (MHC) class II genes in samples from patients who relapsed after HSCT.

However, interferon-gamma “rapidly reversed this phenotype” in vitro, according to the researchers.

Matthew J. Christopher, MD, PhD, of Washington University School of Medicine in St. Louis, Missouri, and his colleagues reported these findings in The New England Journal of Medicine.

The researchers set out to determine how genetic and epigenetic changes after HSCT may allow leukemic cells to avoid the graft-vs-leukemia effect and to see whether immune-related genes are affected by HSCT.

The team analyzed paired samples obtained at diagnosis and relapse from 15 AML patients who relapsed after HSCT and 20 AML patients who relapsed after chemotherapy. The team also analyzed additional samples from patients who relapsed after HSCT to validate initial findings.

Methods of analysis included enhanced exome sequencing, RNA sequencing, flow cytometry, and immunohistochemical analysis.

Findings

The researchers first looked for relapse-specific mutations but found no driver mutations associated with relapse after HSCT.

The mutations seen post-HSCT relapse were generally similar to those seen both before treatment and after relapse in patients who had undergone chemotherapy, and the researchers could not identify any patterns of mutations related to relapse.

They then looked for, but did not find, relapse-specific mutations in genes involved in modulation of immune checkpoints, antigen presentation, or cytokine signaling.

The researchers did, however, find evidence of epigenetic changes that were more common in the samples from patients with post-transplant relapses.

RNA sequencing showed that MHC class II genes (HLA-DPA1, HLA-DPB1, HLA-DQB1, and HLA-DRB1) were downregulated three- to 12-fold after transplant.

Flow cytometry and immunohistochemical analysis confirmed that MHC class II expression was decreased at relapse after HSCT in 17 of 34 samples evaluated.

The researchers said there was no association between the downregulation of MHC class II and donor type or use of immunosuppression.

To see whether the downregulation of MHC class II genes was reversible, the researchers treated three post-HSCT relapse samples with interferon-gamma, which is known to upregulate MHC class II on certain cells.

Culturing patient cells with interferon-gamma “rapidly induced MHC class II protein expression on leukemic blasts,” the researchers said. They observed “essentially full restoration of MHC class II protein expression in nearly all AML blasts after 72 hours.”

This study was supported by the National Institutes of Health, Leukemia and Lymphoma Society, and the Barnes-Jewish Hospital Foundation.

Several study authors reported personal fees and/or research support from industry outside the submitted work.

In patients aged 65 years and older with acute myeloid leukemia (AML), the combination of venetoclax (Venclexta) and a hypomethylating agent had good efficacy and was well tolerated, according to updated results from a phase 1b dose-escalation and expansion trial.

At a median of 8.9 months of study, the overall response rate (ORR) among all treated patients was 68%, with a median duration of complete remission (CR) plus CR with incomplete count recovery (CRi) of 11.3 months, reported Courtney DiNardo, MD, from the University of Texas MD Anderson Center in Houston and her colleagues.

“Venetoclax in combination with azacitidine or decitabine was well tolerated, with similar safety profiles within all arms of the dose escalation and expansion phases in elderly patients with previously untreated AML ineligible for standard induction therapy,” they wrote in a paper published in Blood.

At the 2017 European Hematology Association Congress, the investigators reported that the combined rate of complete remission CR and CRi was 60% among patients with poor-risk cytogenetics and 78% among patients with intermediate-risk disease. In addition, the drug combination was effective among patients with both primary de novo AML (68%) and secondary AML (related to myelodysplasia or myeloproliferative neoplasms or previous therapy; 73%).

In this, the most recent analysis, Dr. DiNardo and her colleagues reported on follow-up of 145 patients aged 65 and older with treatment-naive AML who were not eligible for intensive chemotherapy regimens used for younger adults. The median age was 74 years. Approximately half of all patients (49%) had poor-risk cytogenetics.

The patients were treated with either decitabine or azacitidine plus venetoclax at a dose of either 400 mg or 800 mg. Decitabine was dosed at 20 mg/m² intravenously on days 1-5 of a 28-day cycle. Azacitidine was dosed at 75 mg/m² subcutaneously on days 1-7 of every cycle.

The median time on study was 8.9 months. Among all patients treated at all doses, 67% had either a CR or CRi. The combined CR/CRi rate in patients treated at the 400 mg dose of venetoclax was 73%.

The CR/CRi rate for patients with poor-risk cytogenetics was 60%, and the rate for patients aged 75 years and older was 65%.

Among all patients, the median duration of CR/CRi was 11.3 months, and median overall survival was 17.5 months. In the 400 mg venetoclax cohort, the median duration of CR/CRi was 12.5 months, with the median OS not reached at the time of data cutoff.

Adverse events occurring in 30% or more of patients included constipation, diarrhea, vomiting, nausea, fatigue, febrile neutropenia, hypokalemia, decreased appetite, and decreased white blood cell count. There were no reported cases of the tumor lysis syndrome, a known complication of venetoclax therapy.

Venetoclax plus decitabine or azacitidine was effective in high-risk subgroups, including patients aged 75 years and older, those with poor cytogenetic risk, and those with secondary AML, the investigators noted.

“Though these observations are drawn from a relatively small subset of patients, the remission rates achieved by our low-intensity regimen are encouraging in light of the traditionally lower remission rates in the elderly AML population (40%-50%) compared with young patients receiving chemotherapy (60%-70%) and the relatively short duration of these remissions,” Dr. DiNardo and her colleagues wrote.

A phase 3 trial is currently underway comparing venetoclax at the 400 mg dose plus azacitidine with azacitidine alone in treatment-naive patients with AML who are ineligible for standard induction therapy.

The trial was supported by AbbVie and Genentech. Dr. DiNardo and multiple coauthors disclosed relationships with AbbVie, Genentech, and other companies.

SOURCE: DiNardo C et al. Blood. 2018 Oct 25. doi: 10.1182/blood-2018-08-868752.

In patients aged 65 years and older with acute myeloid leukemia (AML), the combination of venetoclax (Venclexta) and a hypomethylating agent had good efficacy and was well tolerated, according to updated results from a phase 1b dose-escalation and expansion trial.

At a median of 8.9 months of study, the overall response rate (ORR) among all treated patients was 68%, with a median duration of complete remission (CR) plus CR with incomplete count recovery (CRi) of 11.3 months, reported Courtney DiNardo, MD, from the University of Texas MD Anderson Center in Houston and her colleagues.

“Venetoclax in combination with azacitidine or decitabine was well tolerated, with similar safety profiles within all arms of the dose escalation and expansion phases in elderly patients with previously untreated AML ineligible for standard induction therapy,” they wrote in a paper published in Blood.

At the 2017 European Hematology Association Congress, the investigators reported that the combined rate of complete remission CR and CRi was 60% among patients with poor-risk cytogenetics and 78% among patients with intermediate-risk disease. In addition, the drug combination was effective among patients with both primary de novo AML (68%) and secondary AML (related to myelodysplasia or myeloproliferative neoplasms or previous therapy; 73%).

In this, the most recent analysis, Dr. DiNardo and her colleagues reported on follow-up of 145 patients aged 65 and older with treatment-naive AML who were not eligible for intensive chemotherapy regimens used for younger adults. The median age was 74 years. Approximately half of all patients (49%) had poor-risk cytogenetics.

The patients were treated with either decitabine or azacitidine plus venetoclax at a dose of either 400 mg or 800 mg. Decitabine was dosed at 20 mg/m² intravenously on days 1-5 of a 28-day cycle. Azacitidine was dosed at 75 mg/m² subcutaneously on days 1-7 of every cycle.

The median time on study was 8.9 months. Among all patients treated at all doses, 67% had either a CR or CRi. The combined CR/CRi rate in patients treated at the 400 mg dose of venetoclax was 73%.

The CR/CRi rate for patients with poor-risk cytogenetics was 60%, and the rate for patients aged 75 years and older was 65%.

Among all patients, the median duration of CR/CRi was 11.3 months, and median overall survival was 17.5 months. In the 400 mg venetoclax cohort, the median duration of CR/CRi was 12.5 months, with the median OS not reached at the time of data cutoff.

Adverse events occurring in 30% or more of patients included constipation, diarrhea, vomiting, nausea, fatigue, febrile neutropenia, hypokalemia, decreased appetite, and decreased white blood cell count. There were no reported cases of the tumor lysis syndrome, a known complication of venetoclax therapy.

Venetoclax plus decitabine or azacitidine was effective in high-risk subgroups, including patients aged 75 years and older, those with poor cytogenetic risk, and those with secondary AML, the investigators noted.

“Though these observations are drawn from a relatively small subset of patients, the remission rates achieved by our low-intensity regimen are encouraging in light of the traditionally lower remission rates in the elderly AML population (40%-50%) compared with young patients receiving chemotherapy (60%-70%) and the relatively short duration of these remissions,” Dr. DiNardo and her colleagues wrote.

A phase 3 trial is currently underway comparing venetoclax at the 400 mg dose plus azacitidine with azacitidine alone in treatment-naive patients with AML who are ineligible for standard induction therapy.

The trial was supported by AbbVie and Genentech. Dr. DiNardo and multiple coauthors disclosed relationships with AbbVie, Genentech, and other companies.

SOURCE: DiNardo C et al. Blood. 2018 Oct 25. doi: 10.1182/blood-2018-08-868752.

In patients aged 65 years and older with acute myeloid leukemia (AML), the combination of venetoclax (Venclexta) and a hypomethylating agent had good efficacy and was well tolerated, according to updated results from a phase 1b dose-escalation and expansion trial.

At a median of 8.9 months of study, the overall response rate (ORR) among all treated patients was 68%, with a median duration of complete remission (CR) plus CR with incomplete count recovery (CRi) of 11.3 months, reported Courtney DiNardo, MD, from the University of Texas MD Anderson Center in Houston and her colleagues.

“Venetoclax in combination with azacitidine or decitabine was well tolerated, with similar safety profiles within all arms of the dose escalation and expansion phases in elderly patients with previously untreated AML ineligible for standard induction therapy,” they wrote in a paper published in Blood.

At the 2017 European Hematology Association Congress, the investigators reported that the combined rate of complete remission CR and CRi was 60% among patients with poor-risk cytogenetics and 78% among patients with intermediate-risk disease. In addition, the drug combination was effective among patients with both primary de novo AML (68%) and secondary AML (related to myelodysplasia or myeloproliferative neoplasms or previous therapy; 73%).

In this, the most recent analysis, Dr. DiNardo and her colleagues reported on follow-up of 145 patients aged 65 and older with treatment-naive AML who were not eligible for intensive chemotherapy regimens used for younger adults. The median age was 74 years. Approximately half of all patients (49%) had poor-risk cytogenetics.

The patients were treated with either decitabine or azacitidine plus venetoclax at a dose of either 400 mg or 800 mg. Decitabine was dosed at 20 mg/m² intravenously on days 1-5 of a 28-day cycle. Azacitidine was dosed at 75 mg/m² subcutaneously on days 1-7 of every cycle.

The median time on study was 8.9 months. Among all patients treated at all doses, 67% had either a CR or CRi. The combined CR/CRi rate in patients treated at the 400 mg dose of venetoclax was 73%.

The CR/CRi rate for patients with poor-risk cytogenetics was 60%, and the rate for patients aged 75 years and older was 65%.

Among all patients, the median duration of CR/CRi was 11.3 months, and median overall survival was 17.5 months. In the 400 mg venetoclax cohort, the median duration of CR/CRi was 12.5 months, with the median OS not reached at the time of data cutoff.

Adverse events occurring in 30% or more of patients included constipation, diarrhea, vomiting, nausea, fatigue, febrile neutropenia, hypokalemia, decreased appetite, and decreased white blood cell count. There were no reported cases of the tumor lysis syndrome, a known complication of venetoclax therapy.

Venetoclax plus decitabine or azacitidine was effective in high-risk subgroups, including patients aged 75 years and older, those with poor cytogenetic risk, and those with secondary AML, the investigators noted.

“Though these observations are drawn from a relatively small subset of patients, the remission rates achieved by our low-intensity regimen are encouraging in light of the traditionally lower remission rates in the elderly AML population (40%-50%) compared with young patients receiving chemotherapy (60%-70%) and the relatively short duration of these remissions,” Dr. DiNardo and her colleagues wrote.

A phase 3 trial is currently underway comparing venetoclax at the 400 mg dose plus azacitidine with azacitidine alone in treatment-naive patients with AML who are ineligible for standard induction therapy.

The trial was supported by AbbVie and Genentech. Dr. DiNardo and multiple coauthors disclosed relationships with AbbVie, Genentech, and other companies.

SOURCE: DiNardo C et al. Blood. 2018 Oct 25. doi: 10.1182/blood-2018-08-868752.

Relapse of acute myeloid leukemia after hematopoietic stem cell transplantation appears to be related to posttransplant changes in immune function that may be reversible with interferon-gamma therapy, investigators said.

Researchers performed a comparison of acute myeloid leukemia (AML) samples taken from patients before hematopoietic stem cell transplantation (HSCT) and at the time of relapse. They found that, while the general genomic changes seen at relapse resembled changes seen when patients experience relapse after chemotherapy, HSCT was associated with changes in genes believed to control both adaptive and innate immunity.

The findings suggest that transplantation results in a dampening of immune surveillance that could potentially be reversed with interferon gamma, an immunostimulatory cytokine, reported Matthew J. Christopher, MD, PhD, from Washington University, St. Louis, and his colleagues.

“These changes appeared to be epigenetic in nature in at least some cases, which suggests that therapeutic strategies to resensitize AML cells to the graft-versus-leukemia effect may be feasible,” they wrote in the New England Journal of Medicine.

The researchers noted that, while the presence of certain AML mutations may predict risk for relapse following HSCT, “the mechanisms by which these mutations promote relapse remain unclear.”

To get a better sense of how genetic and epigenetic changes after transplantation may allow leukemic cells to avoid the graft-versus-leukemia effect – and to see whether immune-related genes are affected by HSCT – they performed enhanced exome sequencing, flow cytometry, and immunohistochemical analyses on samples from 15 patients with AML who had a relapse after receiving transplants from HLA-matched siblings, matched unrelated donors, or HLA-mismatched unrelated donors, and on paired samples from 20 patients who experienced relapses after chemotherapy.

To validate their findings, they also evaluated samples from 28 other patients with AML who had a relapse after transplantation.

They first looked for relapse-specific mutations, but found no driver mutations associated with relapse after transplantation. The mutations seen during relapse after transplantation were generally similar to those seen both before treatment and after relapse in patients who had undergone chemotherapy. The researchers could not identify any patterns of mutations related to relapse.

They then looked for, but did not find, relapse-specific mutations in genes involved in either modulation of immune checkpoints, antigen presentation, or cytokine signaling.

The researchers did, however, find evidence of epigenetic changes that were more common in the samples of patients with posttransplant relapses, compared with postchemotherapy relapses. Specifically, they found that major histocompatibility (MHC) class II genes were down-regulated 200%-1100% after transplant, compared with the pretransplant samples.

In samples from 17 of 34 patients who experienced a relapse after transplantation, both flow cytometry and immunohistochemical analyses confirmed that expression of MHC class II molecules were decreased at relapse.

To see whether this down-regulation was reversible, the researchers treated samples from three patients with posttransplant relapse with interferon gamma, which is known to up-regulate MHC class II protein on myeloid cells and other cell types.

“Culture of these cells with interferon-gamma rapidly induced MHC class II protein expression on leukemic blasts, with essentially full restoration of MHC class II protein expression in nearly all AML blasts after 72 hours,” they wrote, adding that the reversibility of down-regulation of MHC class II in these blasts “strongly suggests that this phenomenon is mediated by an epigenetic mechanism.”

The study was supported by grants to investigators from the National Institutes of Health, Leukemia & Lymphoma Society, and the Barnes-Jewish Hospital Foundation. Dr. Christopher and several coauthors reported receiving grants from the study funders but no other relevant conflicts of interest. Several coauthors reported receiving personal fees and/or research support from industry outside the submitted work.

SOURCE: Christopher MJ et al. N Engl J Med. 2018 Oct 31. doi: 10.1056/NEJMoa1808777.

Relapse of acute myeloid leukemia after hematopoietic stem cell transplantation appears to be related to posttransplant changes in immune function that may be reversible with interferon-gamma therapy, investigators said.

Researchers performed a comparison of acute myeloid leukemia (AML) samples taken from patients before hematopoietic stem cell transplantation (HSCT) and at the time of relapse. They found that, while the general genomic changes seen at relapse resembled changes seen when patients experience relapse after chemotherapy, HSCT was associated with changes in genes believed to control both adaptive and innate immunity.

The findings suggest that transplantation results in a dampening of immune surveillance that could potentially be reversed with interferon gamma, an immunostimulatory cytokine, reported Matthew J. Christopher, MD, PhD, from Washington University, St. Louis, and his colleagues.

“These changes appeared to be epigenetic in nature in at least some cases, which suggests that therapeutic strategies to resensitize AML cells to the graft-versus-leukemia effect may be feasible,” they wrote in the New England Journal of Medicine.

The researchers noted that, while the presence of certain AML mutations may predict risk for relapse following HSCT, “the mechanisms by which these mutations promote relapse remain unclear.”

To get a better sense of how genetic and epigenetic changes after transplantation may allow leukemic cells to avoid the graft-versus-leukemia effect – and to see whether immune-related genes are affected by HSCT – they performed enhanced exome sequencing, flow cytometry, and immunohistochemical analyses on samples from 15 patients with AML who had a relapse after receiving transplants from HLA-matched siblings, matched unrelated donors, or HLA-mismatched unrelated donors, and on paired samples from 20 patients who experienced relapses after chemotherapy.

To validate their findings, they also evaluated samples from 28 other patients with AML who had a relapse after transplantation.

They first looked for relapse-specific mutations, but found no driver mutations associated with relapse after transplantation. The mutations seen during relapse after transplantation were generally similar to those seen both before treatment and after relapse in patients who had undergone chemotherapy. The researchers could not identify any patterns of mutations related to relapse.

They then looked for, but did not find, relapse-specific mutations in genes involved in either modulation of immune checkpoints, antigen presentation, or cytokine signaling.

The researchers did, however, find evidence of epigenetic changes that were more common in the samples of patients with posttransplant relapses, compared with postchemotherapy relapses. Specifically, they found that major histocompatibility (MHC) class II genes were down-regulated 200%-1100% after transplant, compared with the pretransplant samples.

In samples from 17 of 34 patients who experienced a relapse after transplantation, both flow cytometry and immunohistochemical analyses confirmed that expression of MHC class II molecules were decreased at relapse.

To see whether this down-regulation was reversible, the researchers treated samples from three patients with posttransplant relapse with interferon gamma, which is known to up-regulate MHC class II protein on myeloid cells and other cell types.

“Culture of these cells with interferon-gamma rapidly induced MHC class II protein expression on leukemic blasts, with essentially full restoration of MHC class II protein expression in nearly all AML blasts after 72 hours,” they wrote, adding that the reversibility of down-regulation of MHC class II in these blasts “strongly suggests that this phenomenon is mediated by an epigenetic mechanism.”

The study was supported by grants to investigators from the National Institutes of Health, Leukemia & Lymphoma Society, and the Barnes-Jewish Hospital Foundation. Dr. Christopher and several coauthors reported receiving grants from the study funders but no other relevant conflicts of interest. Several coauthors reported receiving personal fees and/or research support from industry outside the submitted work.

SOURCE: Christopher MJ et al. N Engl J Med. 2018 Oct 31. doi: 10.1056/NEJMoa1808777.

Relapse of acute myeloid leukemia after hematopoietic stem cell transplantation appears to be related to posttransplant changes in immune function that may be reversible with interferon-gamma therapy, investigators said.

Researchers performed a comparison of acute myeloid leukemia (AML) samples taken from patients before hematopoietic stem cell transplantation (HSCT) and at the time of relapse. They found that, while the general genomic changes seen at relapse resembled changes seen when patients experience relapse after chemotherapy, HSCT was associated with changes in genes believed to control both adaptive and innate immunity.

The findings suggest that transplantation results in a dampening of immune surveillance that could potentially be reversed with interferon gamma, an immunostimulatory cytokine, reported Matthew J. Christopher, MD, PhD, from Washington University, St. Louis, and his colleagues.

“These changes appeared to be epigenetic in nature in at least some cases, which suggests that therapeutic strategies to resensitize AML cells to the graft-versus-leukemia effect may be feasible,” they wrote in the New England Journal of Medicine.

The researchers noted that, while the presence of certain AML mutations may predict risk for relapse following HSCT, “the mechanisms by which these mutations promote relapse remain unclear.”

To get a better sense of how genetic and epigenetic changes after transplantation may allow leukemic cells to avoid the graft-versus-leukemia effect – and to see whether immune-related genes are affected by HSCT – they performed enhanced exome sequencing, flow cytometry, and immunohistochemical analyses on samples from 15 patients with AML who had a relapse after receiving transplants from HLA-matched siblings, matched unrelated donors, or HLA-mismatched unrelated donors, and on paired samples from 20 patients who experienced relapses after chemotherapy.

To validate their findings, they also evaluated samples from 28 other patients with AML who had a relapse after transplantation.

They first looked for relapse-specific mutations, but found no driver mutations associated with relapse after transplantation. The mutations seen during relapse after transplantation were generally similar to those seen both before treatment and after relapse in patients who had undergone chemotherapy. The researchers could not identify any patterns of mutations related to relapse.

They then looked for, but did not find, relapse-specific mutations in genes involved in either modulation of immune checkpoints, antigen presentation, or cytokine signaling.

The researchers did, however, find evidence of epigenetic changes that were more common in the samples of patients with posttransplant relapses, compared with postchemotherapy relapses. Specifically, they found that major histocompatibility (MHC) class II genes were down-regulated 200%-1100% after transplant, compared with the pretransplant samples.

In samples from 17 of 34 patients who experienced a relapse after transplantation, both flow cytometry and immunohistochemical analyses confirmed that expression of MHC class II molecules were decreased at relapse.

To see whether this down-regulation was reversible, the researchers treated samples from three patients with posttransplant relapse with interferon gamma, which is known to up-regulate MHC class II protein on myeloid cells and other cell types.

“Culture of these cells with interferon-gamma rapidly induced MHC class II protein expression on leukemic blasts, with essentially full restoration of MHC class II protein expression in nearly all AML blasts after 72 hours,” they wrote, adding that the reversibility of down-regulation of MHC class II in these blasts “strongly suggests that this phenomenon is mediated by an epigenetic mechanism.”

The study was supported by grants to investigators from the National Institutes of Health, Leukemia & Lymphoma Society, and the Barnes-Jewish Hospital Foundation. Dr. Christopher and several coauthors reported receiving grants from the study funders but no other relevant conflicts of interest. Several coauthors reported receiving personal fees and/or research support from industry outside the submitted work.

SOURCE: Christopher MJ et al. N Engl J Med. 2018 Oct 31. doi: 10.1056/NEJMoa1808777.

Image by Lance Liotta

Preclinical research suggests the oncoprotein EVI1 can promote leukemogenesis by suppressing erythropoiesis and lymphopoiesis while shifting differentiation toward the expansion of myeloid cells.

Researchers developed a new mouse model that mimics chromosomal rearrangements at 3q26, which are associated with poor-prognosis acute myeloid leukemia (AML), myelodysplastic syndromes, and myeloproliferative neoplasms.

Using the mouse model, the team demonstrated that EVI1 overexpression distorts hematopoiesis and markedly expands premalignant myelopoiesis that eventually results in leukemic transformation.

Archibald Perkins, MD, PhD, of the University of Rochester Medical Center in New York, and his colleagues published these findings in Nature Communications.

The team demonstrated that the “myeloid-skewed phenotype” is dependent upon EVI1-binding DNA. This upregulates Spi1 and encodes the master myeloid regulator PU.1.

When the researchers knocked down Spi1, the myeloid skewing diminished.

“It’s not so pie-in-the-sky anymore,” Dr. Perkins said, “to think we can interrupt the process within the genome that leads to leukemia.”

The researchers first created a mouse model of 3q26 AML with a tetracycline-inducible allele of EVI1 by inserting tetracycline operons within the first exon. This allowed the induction of all three isoforms of EVI1.

These mice were viable and fertile but had no phenotype, which indicated that the allele functioned normally unless induced.

To assess the effect of EVI1 overexpression, the researchers transplanted oncogene-expressing bone marrow mixed 1:1 with wild-type bone marrow into recipient mice.

After confirming successful engraftment, the researchers fed the mice doxycycline-treated food to induce EVI1. The team analyzed cells in the peripheral blood and bone marrow at 10 weeks post-induction.

The researchers observed a more than two-fold expansion of the EVI1-overexpressing compartment in the mouse model.

Suppression of erythropoiesis

The researchers analyzed erythroid lineage in the transplanted mice at 2, 6, and 10 weeks post-induction and found the EVI1-overexpressing cells did not contribute effectively to erythropoiesis.

Using flow cytometry, the researchers quantitated apoptosis and proliferation in erythroid progenitors. They observed a six-fold increase in apoptosis within the erythroblasts compared to wild-type cells.

They also observed a drop in the proliferation of proerythroblasts and erythroblasts compared to wild-type.

Suppression of lymphopoiesis

The researchers observed significantly lower numbers of EVI1-overexpressing B-lineage cells within the bone marrow at 6 and 10 weeks.

And at 10 weeks post-induction, the team observed a decrease in peripheral T cells from approximately 1,800 cells/µL to approximately 750 cells/µL.

EVI1 nearly eliminated the peripheral B cells completely, they noted.

Expansion of myelopoiesis

The team reported that, at 2 weeks post-induction, the EVI1-overexpressing bone marrow and control bone marrow showed the same number of myeloid cells.

But at 6 and 10 weeks post-induction, the EVI1-overexpressing myeloid compartment expanded markedly.

The researchers aged a cohort of five mice transplanted with the 1:1 mix of wild-type and EVI1 bone marrow cells to determine if chronic overexpression of EVI1 results in leukemia.

All five mice died at 90 to 119 days of doxycycline treatment. Analysis revealed AML in all mice. Bone marrows were replete with blasts, and the peripheral blood revealed severe anemia.

The researchers then proceeded to establish the relationship between EVI1 and Spi1/PU.1 transcriptional regulation.

They documented binding of EVI1 to the regulatory element -14kbURE, which, together with EVI1., induced upregulation of PU.1.

When the team knocked down PU.1, myeloid skewing diminished. This, they say, indicates PU.1 is necessary for EVI1-induced myeloid expansion.

Funding for this research was provided by the National Institutes of Health, New York State Stem Cell Science, the Wilmot Cancer Institute, and the Clinical and Translational Science Institute at the University of Rochester.

The authors had no competing interests to disclose. 

Image by Lance Liotta

Preclinical research suggests the oncoprotein EVI1 can promote leukemogenesis by suppressing erythropoiesis and lymphopoiesis while shifting differentiation toward the expansion of myeloid cells.

Researchers developed a new mouse model that mimics chromosomal rearrangements at 3q26, which are associated with poor-prognosis acute myeloid leukemia (AML), myelodysplastic syndromes, and myeloproliferative neoplasms.

Using the mouse model, the team demonstrated that EVI1 overexpression distorts hematopoiesis and markedly expands premalignant myelopoiesis that eventually results in leukemic transformation.

Archibald Perkins, MD, PhD, of the University of Rochester Medical Center in New York, and his colleagues published these findings in Nature Communications.

The team demonstrated that the “myeloid-skewed phenotype” is dependent upon EVI1-binding DNA. This upregulates Spi1 and encodes the master myeloid regulator PU.1.

When the researchers knocked down Spi1, the myeloid skewing diminished.

“It’s not so pie-in-the-sky anymore,” Dr. Perkins said, “to think we can interrupt the process within the genome that leads to leukemia.”

The researchers first created a mouse model of 3q26 AML with a tetracycline-inducible allele of EVI1 by inserting tetracycline operons within the first exon. This allowed the induction of all three isoforms of EVI1.

These mice were viable and fertile but had no phenotype, which indicated that the allele functioned normally unless induced.

To assess the effect of EVI1 overexpression, the researchers transplanted oncogene-expressing bone marrow mixed 1:1 with wild-type bone marrow into recipient mice.

After confirming successful engraftment, the researchers fed the mice doxycycline-treated food to induce EVI1. The team analyzed cells in the peripheral blood and bone marrow at 10 weeks post-induction.

The researchers observed a more than two-fold expansion of the EVI1-overexpressing compartment in the mouse model.

Suppression of erythropoiesis

The researchers analyzed erythroid lineage in the transplanted mice at 2, 6, and 10 weeks post-induction and found the EVI1-overexpressing cells did not contribute effectively to erythropoiesis.

Using flow cytometry, the researchers quantitated apoptosis and proliferation in erythroid progenitors. They observed a six-fold increase in apoptosis within the erythroblasts compared to wild-type cells.

They also observed a drop in the proliferation of proerythroblasts and erythroblasts compared to wild-type.

Suppression of lymphopoiesis

The researchers observed significantly lower numbers of EVI1-overexpressing B-lineage cells within the bone marrow at 6 and 10 weeks.

And at 10 weeks post-induction, the team observed a decrease in peripheral T cells from approximately 1,800 cells/µL to approximately 750 cells/µL.

EVI1 nearly eliminated the peripheral B cells completely, they noted.

Expansion of myelopoiesis

The team reported that, at 2 weeks post-induction, the EVI1-overexpressing bone marrow and control bone marrow showed the same number of myeloid cells.

But at 6 and 10 weeks post-induction, the EVI1-overexpressing myeloid compartment expanded markedly.

The researchers aged a cohort of five mice transplanted with the 1:1 mix of wild-type and EVI1 bone marrow cells to determine if chronic overexpression of EVI1 results in leukemia.

All five mice died at 90 to 119 days of doxycycline treatment. Analysis revealed AML in all mice. Bone marrows were replete with blasts, and the peripheral blood revealed severe anemia.

The researchers then proceeded to establish the relationship between EVI1 and Spi1/PU.1 transcriptional regulation.

They documented binding of EVI1 to the regulatory element -14kbURE, which, together with EVI1., induced upregulation of PU.1.

When the team knocked down PU.1, myeloid skewing diminished. This, they say, indicates PU.1 is necessary for EVI1-induced myeloid expansion.

Funding for this research was provided by the National Institutes of Health, New York State Stem Cell Science, the Wilmot Cancer Institute, and the Clinical and Translational Science Institute at the University of Rochester.

The authors had no competing interests to disclose. 

Image by Lance Liotta

Preclinical research suggests the oncoprotein EVI1 can promote leukemogenesis by suppressing erythropoiesis and lymphopoiesis while shifting differentiation toward the expansion of myeloid cells.

Researchers developed a new mouse model that mimics chromosomal rearrangements at 3q26, which are associated with poor-prognosis acute myeloid leukemia (AML), myelodysplastic syndromes, and myeloproliferative neoplasms.

Using the mouse model, the team demonstrated that EVI1 overexpression distorts hematopoiesis and markedly expands premalignant myelopoiesis that eventually results in leukemic transformation.

Archibald Perkins, MD, PhD, of the University of Rochester Medical Center in New York, and his colleagues published these findings in Nature Communications.

The team demonstrated that the “myeloid-skewed phenotype” is dependent upon EVI1-binding DNA. This upregulates Spi1 and encodes the master myeloid regulator PU.1.

When the researchers knocked down Spi1, the myeloid skewing diminished.

“It’s not so pie-in-the-sky anymore,” Dr. Perkins said, “to think we can interrupt the process within the genome that leads to leukemia.”

The researchers first created a mouse model of 3q26 AML with a tetracycline-inducible allele of EVI1 by inserting tetracycline operons within the first exon. This allowed the induction of all three isoforms of EVI1.

These mice were viable and fertile but had no phenotype, which indicated that the allele functioned normally unless induced.

To assess the effect of EVI1 overexpression, the researchers transplanted oncogene-expressing bone marrow mixed 1:1 with wild-type bone marrow into recipient mice.

After confirming successful engraftment, the researchers fed the mice doxycycline-treated food to induce EVI1. The team analyzed cells in the peripheral blood and bone marrow at 10 weeks post-induction.

The researchers observed a more than two-fold expansion of the EVI1-overexpressing compartment in the mouse model.

Suppression of erythropoiesis

The researchers analyzed erythroid lineage in the transplanted mice at 2, 6, and 10 weeks post-induction and found the EVI1-overexpressing cells did not contribute effectively to erythropoiesis.

Using flow cytometry, the researchers quantitated apoptosis and proliferation in erythroid progenitors. They observed a six-fold increase in apoptosis within the erythroblasts compared to wild-type cells.

They also observed a drop in the proliferation of proerythroblasts and erythroblasts compared to wild-type.

Suppression of lymphopoiesis

The researchers observed significantly lower numbers of EVI1-overexpressing B-lineage cells within the bone marrow at 6 and 10 weeks.

And at 10 weeks post-induction, the team observed a decrease in peripheral T cells from approximately 1,800 cells/µL to approximately 750 cells/µL.

EVI1 nearly eliminated the peripheral B cells completely, they noted.

Expansion of myelopoiesis

The team reported that, at 2 weeks post-induction, the EVI1-overexpressing bone marrow and control bone marrow showed the same number of myeloid cells.

But at 6 and 10 weeks post-induction, the EVI1-overexpressing myeloid compartment expanded markedly.

The researchers aged a cohort of five mice transplanted with the 1:1 mix of wild-type and EVI1 bone marrow cells to determine if chronic overexpression of EVI1 results in leukemia.

All five mice died at 90 to 119 days of doxycycline treatment. Analysis revealed AML in all mice. Bone marrows were replete with blasts, and the peripheral blood revealed severe anemia.

The researchers then proceeded to establish the relationship between EVI1 and Spi1/PU.1 transcriptional regulation.

They documented binding of EVI1 to the regulatory element -14kbURE, which, together with EVI1., induced upregulation of PU.1.

When the team knocked down PU.1, myeloid skewing diminished. This, they say, indicates PU.1 is necessary for EVI1-induced myeloid expansion.

Funding for this research was provided by the National Institutes of Health, New York State Stem Cell Science, the Wilmot Cancer Institute, and the Clinical and Translational Science Institute at the University of Rochester.

The authors had no competing interests to disclose. 

Image courtesy of P. Eyers

Researchers have found the cancer-associated pseudokinase Tribbles 2 (TRIB2) to be a potential therapeutic target in solid tumors and blood cancers, including acute myeloid leukemia (AML).

Previous research had described TRIB2 as a target of small-molecule protein kinase inhibitors originally designed to interfere with kinase domains of the epidermal growth factor receptor (EGFR) tyrosine kinase family.

Using a thermal shift assay, the team discovered TRIB2-binding compounds within the Published Kinase Inhibitor Set (PKIS). They then employed a biochemical drug repurposing approach to classify compounds that either stabilized or destabilized TRIB2 in vitro.

The researchers found that afatinib, which is already approved by the U.S. Food and Drug Administration to treat non-small cell lung cancer, led to rapid TRIB2 degradation in human AML cells.

Patrick A. Eyers, PhD, of the University of Liverpool in the U.K., and his colleagues published their findings in Science Signaling.

The team found afatinib to be relatively specific for EGFR and human epidermal growth factor receptor 2 (HER2) at nanomolar concentrations in cells.

The researchers confirmed that at least two TRIB2 Cys residues interact with afatinib in vitro.

The team also discovered TRIB2 could be destabilized by neratinib and osimertinib in vitro.

“Our data prove that the cellular mechanism by which TRIB2 stability is regulated by compounds is proteasome-based,” the researchers wrote, “and we speculate that an afatinib-induced conformational change might induce TRIB2 ubiquitination.”

The researchers plan to study further TRIB2 small-molecule interactions with dynamic changes in ubiquitination status.

Furthermore, they report their work demonstrates that covalent inhibitors such as afatinib have TRIB2-degrading activity in human cells at micromolar concentrations.

The researchers determined that afatinib has similar efficacy to the TRIB2-destabilizing quinazoline neratinib at similar ranges.

The team believes their data “raise the intriguing possibility that clinical inhibitors might be used as TRIB2-degrading agents in research, and possibly clinical, contexts.”

“A long-standing goal in cancer research is drug-induced degradation of oncogenic proteins,” Dr. Eyers commented. “Our study highlights how information obtained with ‘off-target’ effects of known drugs is potentially useful because it might be exploited in the future to help eliminate a protein that is involved in a completely different type of cancer.”

The TRIB proteins play many diverse roles in cell signaling, development, and cancer. According to a paper in Developmental Dynamics, they were named after the small, round, fictional organisms from the original Star Trek television series. Their major role was to eat and reproduce.

This work was funded by two U.K. Biotechnology and Biological Sciences Research Council Doctoral Training Partnership studentships, a Tools and Resources Development Fund award, Royal Society Research Grants, North West Cancer Research grants, and funding from the National Institutes of Health.

The authors disclosed no perceived conflicts of interest, although several authors are affiliated with the Structural Genomics Consortium at the University of North Carolina at Chapel Hill, which receives direct funds from various pharmaceutical companies but remains entirely independent. 

Image courtesy of P. Eyers

Researchers have found the cancer-associated pseudokinase Tribbles 2 (TRIB2) to be a potential therapeutic target in solid tumors and blood cancers, including acute myeloid leukemia (AML).

Previous research had described TRIB2 as a target of small-molecule protein kinase inhibitors originally designed to interfere with kinase domains of the epidermal growth factor receptor (EGFR) tyrosine kinase family.

Using a thermal shift assay, the team discovered TRIB2-binding compounds within the Published Kinase Inhibitor Set (PKIS). They then employed a biochemical drug repurposing approach to classify compounds that either stabilized or destabilized TRIB2 in vitro.

The researchers found that afatinib, which is already approved by the U.S. Food and Drug Administration to treat non-small cell lung cancer, led to rapid TRIB2 degradation in human AML cells.

Patrick A. Eyers, PhD, of the University of Liverpool in the U.K., and his colleagues published their findings in Science Signaling.

The team found afatinib to be relatively specific for EGFR and human epidermal growth factor receptor 2 (HER2) at nanomolar concentrations in cells.

The researchers confirmed that at least two TRIB2 Cys residues interact with afatinib in vitro.

The team also discovered TRIB2 could be destabilized by neratinib and osimertinib in vitro.

“Our data prove that the cellular mechanism by which TRIB2 stability is regulated by compounds is proteasome-based,” the researchers wrote, “and we speculate that an afatinib-induced conformational change might induce TRIB2 ubiquitination.”

The researchers plan to study further TRIB2 small-molecule interactions with dynamic changes in ubiquitination status.

Furthermore, they report their work demonstrates that covalent inhibitors such as afatinib have TRIB2-degrading activity in human cells at micromolar concentrations.

The researchers determined that afatinib has similar efficacy to the TRIB2-destabilizing quinazoline neratinib at similar ranges.

The team believes their data “raise the intriguing possibility that clinical inhibitors might be used as TRIB2-degrading agents in research, and possibly clinical, contexts.”

“A long-standing goal in cancer research is drug-induced degradation of oncogenic proteins,” Dr. Eyers commented. “Our study highlights how information obtained with ‘off-target’ effects of known drugs is potentially useful because it might be exploited in the future to help eliminate a protein that is involved in a completely different type of cancer.”

The TRIB proteins play many diverse roles in cell signaling, development, and cancer. According to a paper in Developmental Dynamics, they were named after the small, round, fictional organisms from the original Star Trek television series. Their major role was to eat and reproduce.

This work was funded by two U.K. Biotechnology and Biological Sciences Research Council Doctoral Training Partnership studentships, a Tools and Resources Development Fund award, Royal Society Research Grants, North West Cancer Research grants, and funding from the National Institutes of Health.

The authors disclosed no perceived conflicts of interest, although several authors are affiliated with the Structural Genomics Consortium at the University of North Carolina at Chapel Hill, which receives direct funds from various pharmaceutical companies but remains entirely independent. 

Image courtesy of P. Eyers

Researchers have found the cancer-associated pseudokinase Tribbles 2 (TRIB2) to be a potential therapeutic target in solid tumors and blood cancers, including acute myeloid leukemia (AML).

Previous research had described TRIB2 as a target of small-molecule protein kinase inhibitors originally designed to interfere with kinase domains of the epidermal growth factor receptor (EGFR) tyrosine kinase family.

Using a thermal shift assay, the team discovered TRIB2-binding compounds within the Published Kinase Inhibitor Set (PKIS). They then employed a biochemical drug repurposing approach to classify compounds that either stabilized or destabilized TRIB2 in vitro.

The researchers found that afatinib, which is already approved by the U.S. Food and Drug Administration to treat non-small cell lung cancer, led to rapid TRIB2 degradation in human AML cells.

Patrick A. Eyers, PhD, of the University of Liverpool in the U.K., and his colleagues published their findings in Science Signaling.

The team found afatinib to be relatively specific for EGFR and human epidermal growth factor receptor 2 (HER2) at nanomolar concentrations in cells.

The researchers confirmed that at least two TRIB2 Cys residues interact with afatinib in vitro.

The team also discovered TRIB2 could be destabilized by neratinib and osimertinib in vitro.

“Our data prove that the cellular mechanism by which TRIB2 stability is regulated by compounds is proteasome-based,” the researchers wrote, “and we speculate that an afatinib-induced conformational change might induce TRIB2 ubiquitination.”

The researchers plan to study further TRIB2 small-molecule interactions with dynamic changes in ubiquitination status.

Furthermore, they report their work demonstrates that covalent inhibitors such as afatinib have TRIB2-degrading activity in human cells at micromolar concentrations.

The researchers determined that afatinib has similar efficacy to the TRIB2-destabilizing quinazoline neratinib at similar ranges.

The team believes their data “raise the intriguing possibility that clinical inhibitors might be used as TRIB2-degrading agents in research, and possibly clinical, contexts.”

“A long-standing goal in cancer research is drug-induced degradation of oncogenic proteins,” Dr. Eyers commented. “Our study highlights how information obtained with ‘off-target’ effects of known drugs is potentially useful because it might be exploited in the future to help eliminate a protein that is involved in a completely different type of cancer.”

The TRIB proteins play many diverse roles in cell signaling, development, and cancer. According to a paper in Developmental Dynamics, they were named after the small, round, fictional organisms from the original Star Trek television series. Their major role was to eat and reproduce.

This work was funded by two U.K. Biotechnology and Biological Sciences Research Council Doctoral Training Partnership studentships, a Tools and Resources Development Fund award, Royal Society Research Grants, North West Cancer Research grants, and funding from the National Institutes of Health.

The authors disclosed no perceived conflicts of interest, although several authors are affiliated with the Structural Genomics Consortium at the University of North Carolina at Chapel Hill, which receives direct funds from various pharmaceutical companies but remains entirely independent. 

Photo by Aaron Logan

Researchers have identified a promising therapeutic target for t(8;21) acute myeloid leukemia (AML), according to preclinical data published in Cancer Cell.

The fusion protein RUNX1/ETO drives t(8;21) AML by promoting cell-cycle progression.

Using an RNAi screen, the team recognized the cell-cycle regulator cyclin D2 (CCND2) as having critical involvement in RUNX1/ETO-driven leukemia propagation.

And when they knocked down CCND2 with palbociclib, a drug already approved for breast cancer, leukemic expansion of human AML cells and engraftment in murine models were significantly impaired.

"Our discovery that this treatment can be effective in AML is an important step towards a more effective and less toxic treatment for patients with this form of leukemia,” said study author Olaf Heidenreich, PhD, from the Wolfson Childhood Cancer Research Centre at Newcastle University in the U.K.

After identifying the fusion protein with the RNAi screen, the investigators determined that RUNX1/ETO regulates CCND2 transcription. They knocked down the fusion protein and found the expression of CCND2 was diminished in primary AML blasts. They therefore concluded that RUNX1/ETO maintains CCND2 expression.

The team then examined the significance of CCND2 in engraftment, proliferation, and clonal expansion of AML cells and its impact on the accumulation of cells in the G1 phase of the cell cycle. They found that depletion of CCND2 inhibited cell proliferation and clonogenic capacity and arrested the cell cycle in G0/G1 without increasing apoptosis.

They also confirmed that knockdown of RUNX1/ETO or CCND2 did not affect the expression of other D cyclins and G1 cyclin-dependent kinase (CDK)-CCND complexes, such as CDK4/6.

Next, they explored whether RUNX1/ETO-expressing cells were sensitive to the CDK4/6 inhibitor palbociclib. AML cells were highly sensitive to palbociclib and did not proliferate during drug exposure.

The researchers cultured cells from t(8;21)-positive and -negative AML patients and found palbociclib to cause a dose-dependent inhibition of proliferation of AML blasts.

They also tested palbociclib on a sample from a relapsed t(8;21) AML patient. The sample was highly sensitive to palbociclib, with a five-fold reduction in cell numbers using 300 nM of drug.

The investigators conducted in vivo experiments with palbociclib in mice transplanted with AML cells. Mice treated with palbociclib at doses of 100–150 mg/kg had a significantly longer survival than control mice.

Finally, the team examined whether interference with G1 CDK activity would create other vulnerabilities, such as activating KIT mutations, which are frequent secondary mutations found in t(8;21) AML.

They found that G1 CDK inhibition sensitized AML cells toward KIT inhibition, suggesting that “concurrent targeting of the two mutations may offer substantial therapeutic benefit.”

The team plans to conduct experiments that will refine the precise palbociclib dose in AML either as a single agent or in combination.

This study was supported by grants from Bloodwise, Children with Cancer, North of England Children’s Cancer Research Fund, Children's Cancer and Leukaemia Group, and a CRUK program grant in addition to an Aga Khan PhD studentship, a University Sains Malaysia PhD studentship, and an NC3R fellowship.

The authors had no competing interests to disclose. 

Photo by Aaron Logan

Researchers have identified a promising therapeutic target for t(8;21) acute myeloid leukemia (AML), according to preclinical data published in Cancer Cell.

The fusion protein RUNX1/ETO drives t(8;21) AML by promoting cell-cycle progression.

Using an RNAi screen, the team recognized the cell-cycle regulator cyclin D2 (CCND2) as having critical involvement in RUNX1/ETO-driven leukemia propagation.

And when they knocked down CCND2 with palbociclib, a drug already approved for breast cancer, leukemic expansion of human AML cells and engraftment in murine models were significantly impaired.

"Our discovery that this treatment can be effective in AML is an important step towards a more effective and less toxic treatment for patients with this form of leukemia,” said study author Olaf Heidenreich, PhD, from the Wolfson Childhood Cancer Research Centre at Newcastle University in the U.K.

After identifying the fusion protein with the RNAi screen, the investigators determined that RUNX1/ETO regulates CCND2 transcription. They knocked down the fusion protein and found the expression of CCND2 was diminished in primary AML blasts. They therefore concluded that RUNX1/ETO maintains CCND2 expression.

The team then examined the significance of CCND2 in engraftment, proliferation, and clonal expansion of AML cells and its impact on the accumulation of cells in the G1 phase of the cell cycle. They found that depletion of CCND2 inhibited cell proliferation and clonogenic capacity and arrested the cell cycle in G0/G1 without increasing apoptosis.

They also confirmed that knockdown of RUNX1/ETO or CCND2 did not affect the expression of other D cyclins and G1 cyclin-dependent kinase (CDK)-CCND complexes, such as CDK4/6.

Next, they explored whether RUNX1/ETO-expressing cells were sensitive to the CDK4/6 inhibitor palbociclib. AML cells were highly sensitive to palbociclib and did not proliferate during drug exposure.

The researchers cultured cells from t(8;21)-positive and -negative AML patients and found palbociclib to cause a dose-dependent inhibition of proliferation of AML blasts.

They also tested palbociclib on a sample from a relapsed t(8;21) AML patient. The sample was highly sensitive to palbociclib, with a five-fold reduction in cell numbers using 300 nM of drug.

The investigators conducted in vivo experiments with palbociclib in mice transplanted with AML cells. Mice treated with palbociclib at doses of 100–150 mg/kg had a significantly longer survival than control mice.

Finally, the team examined whether interference with G1 CDK activity would create other vulnerabilities, such as activating KIT mutations, which are frequent secondary mutations found in t(8;21) AML.

They found that G1 CDK inhibition sensitized AML cells toward KIT inhibition, suggesting that “concurrent targeting of the two mutations may offer substantial therapeutic benefit.”

The team plans to conduct experiments that will refine the precise palbociclib dose in AML either as a single agent or in combination.

This study was supported by grants from Bloodwise, Children with Cancer, North of England Children’s Cancer Research Fund, Children's Cancer and Leukaemia Group, and a CRUK program grant in addition to an Aga Khan PhD studentship, a University Sains Malaysia PhD studentship, and an NC3R fellowship.

The authors had no competing interests to disclose. 

Photo by Aaron Logan

Researchers have identified a promising therapeutic target for t(8;21) acute myeloid leukemia (AML), according to preclinical data published in Cancer Cell.

The fusion protein RUNX1/ETO drives t(8;21) AML by promoting cell-cycle progression.

Using an RNAi screen, the team recognized the cell-cycle regulator cyclin D2 (CCND2) as having critical involvement in RUNX1/ETO-driven leukemia propagation.

And when they knocked down CCND2 with palbociclib, a drug already approved for breast cancer, leukemic expansion of human AML cells and engraftment in murine models were significantly impaired.

"Our discovery that this treatment can be effective in AML is an important step towards a more effective and less toxic treatment for patients with this form of leukemia,” said study author Olaf Heidenreich, PhD, from the Wolfson Childhood Cancer Research Centre at Newcastle University in the U.K.

After identifying the fusion protein with the RNAi screen, the investigators determined that RUNX1/ETO regulates CCND2 transcription. They knocked down the fusion protein and found the expression of CCND2 was diminished in primary AML blasts. They therefore concluded that RUNX1/ETO maintains CCND2 expression.

The team then examined the significance of CCND2 in engraftment, proliferation, and clonal expansion of AML cells and its impact on the accumulation of cells in the G1 phase of the cell cycle. They found that depletion of CCND2 inhibited cell proliferation and clonogenic capacity and arrested the cell cycle in G0/G1 without increasing apoptosis.

They also confirmed that knockdown of RUNX1/ETO or CCND2 did not affect the expression of other D cyclins and G1 cyclin-dependent kinase (CDK)-CCND complexes, such as CDK4/6.

Next, they explored whether RUNX1/ETO-expressing cells were sensitive to the CDK4/6 inhibitor palbociclib. AML cells were highly sensitive to palbociclib and did not proliferate during drug exposure.

The researchers cultured cells from t(8;21)-positive and -negative AML patients and found palbociclib to cause a dose-dependent inhibition of proliferation of AML blasts.

They also tested palbociclib on a sample from a relapsed t(8;21) AML patient. The sample was highly sensitive to palbociclib, with a five-fold reduction in cell numbers using 300 nM of drug.

The investigators conducted in vivo experiments with palbociclib in mice transplanted with AML cells. Mice treated with palbociclib at doses of 100–150 mg/kg had a significantly longer survival than control mice.

Finally, the team examined whether interference with G1 CDK activity would create other vulnerabilities, such as activating KIT mutations, which are frequent secondary mutations found in t(8;21) AML.

They found that G1 CDK inhibition sensitized AML cells toward KIT inhibition, suggesting that “concurrent targeting of the two mutations may offer substantial therapeutic benefit.”

The team plans to conduct experiments that will refine the precise palbociclib dose in AML either as a single agent or in combination.

This study was supported by grants from Bloodwise, Children with Cancer, North of England Children’s Cancer Research Fund, Children's Cancer and Leukaemia Group, and a CRUK program grant in addition to an Aga Khan PhD studentship, a University Sains Malaysia PhD studentship, and an NC3R fellowship.

The authors had no competing interests to disclose.