Leukemia, Myelodysplasia, Transplantation

Henrique Orlandi Mourao

CHICAGO—The bispecific antibody APVO436 has demonstrated robust T-cell activation with limited cytokine release in acute myeloid leukemia (AML), according to researchers.

APVO436 binds CD123 and CD3 to redirect T-cell cytotoxicity against CD123-expressing tumor cells.

Researchers found that APVO436 induced T-cell cytotoxicity in AML cells in vitro and in mouse models.

In addition, levels of several cytokines were lower in experiments with APVO436 than in experiments with a comparator antibody.

These findings were presented in a poster at the AACR Annual Meeting 2018 (abstract 1786).

The research was conducted by employees of Aptevo Therapeutics Inc., the company developing APVO436.

“We are especially excited about these latest data for APVO436, which continue to show robust T-cell engagement and cytotoxic activity with reduced levels of cytokine release,” said Jane Gross, PhD, senior vice president and chief scientific officer for Aptevo.

Dr Gross and her colleagues found that APVO436 binds human CD123 and CD3-expressing cells and has “potent” target-specific activity against CD123-expressing AML cell lines (Molm-13 and KG-1a).

In addition, APVO436 induced endogenous T-cell activation and proliferation, accompanied by depletion of CD123-expressing cells, in samples from AML patients and healthy donors.

T cells from these cultures (both AML and non-AML) were expanded and co-cultured with Molm-13 cells and APVO436 or a control antibody. Again, the researchers observed “potent” cytotoxic activity in the presence of APVO436.

Dr Gross and her colleagues also tested APVO436, co-administered with human T cells, in mice with established disseminated Molm-13 tumors. The treatment resulted in a “rapid and significant” reduction in skeletal tumor burden.

Finally, the team compared APVO436 with an Aptevo-generated version of MGD006, a CD123 x CD3 dual-affinity re-targeting molecule being developed by Macrogenics, Inc.

The researchers took purified T cells from healthy donors and cultured them with Molm-13 cells, as well as APVO436, Aptevo’s version of MGD006, and a control antibody.

Both APVO436 and Aptevo’s version of MGD006 were effective at stimulating a tumor-directed immune response, inducing comparable levels of T-cell activation, proliferation, and cytotoxicity.

However, APVO436 induced lower levels of several cytokines—including IFNγ, IL-2, IL-6, and TNFα.

“Importantly, IFNγ, IL-6, and TNFα are considered to be the most relevant cytokines responsible for dosing toxicities observed in clinical studies with T-cell engaging molecules, which suggests that APVO436 could offer the potential for reduced toxicities compared to other CD123 x CD3 T-cell engagers at comparable or higher doses,” Dr Gross said.

She added that Aptevo is planning to launch a phase 1 trial of APVO436 in patients with AML and myelodysplastic syndromes later this year.

Henrique Orlandi Mourao

CHICAGO—The bispecific antibody APVO436 has demonstrated robust T-cell activation with limited cytokine release in acute myeloid leukemia (AML), according to researchers.

APVO436 binds CD123 and CD3 to redirect T-cell cytotoxicity against CD123-expressing tumor cells.

Researchers found that APVO436 induced T-cell cytotoxicity in AML cells in vitro and in mouse models.

In addition, levels of several cytokines were lower in experiments with APVO436 than in experiments with a comparator antibody.

These findings were presented in a poster at the AACR Annual Meeting 2018 (abstract 1786).

The research was conducted by employees of Aptevo Therapeutics Inc., the company developing APVO436.

“We are especially excited about these latest data for APVO436, which continue to show robust T-cell engagement and cytotoxic activity with reduced levels of cytokine release,” said Jane Gross, PhD, senior vice president and chief scientific officer for Aptevo.

Dr Gross and her colleagues found that APVO436 binds human CD123 and CD3-expressing cells and has “potent” target-specific activity against CD123-expressing AML cell lines (Molm-13 and KG-1a).

In addition, APVO436 induced endogenous T-cell activation and proliferation, accompanied by depletion of CD123-expressing cells, in samples from AML patients and healthy donors.

T cells from these cultures (both AML and non-AML) were expanded and co-cultured with Molm-13 cells and APVO436 or a control antibody. Again, the researchers observed “potent” cytotoxic activity in the presence of APVO436.

Dr Gross and her colleagues also tested APVO436, co-administered with human T cells, in mice with established disseminated Molm-13 tumors. The treatment resulted in a “rapid and significant” reduction in skeletal tumor burden.

Finally, the team compared APVO436 with an Aptevo-generated version of MGD006, a CD123 x CD3 dual-affinity re-targeting molecule being developed by Macrogenics, Inc.

The researchers took purified T cells from healthy donors and cultured them with Molm-13 cells, as well as APVO436, Aptevo’s version of MGD006, and a control antibody.

Both APVO436 and Aptevo’s version of MGD006 were effective at stimulating a tumor-directed immune response, inducing comparable levels of T-cell activation, proliferation, and cytotoxicity.

However, APVO436 induced lower levels of several cytokines—including IFNγ, IL-2, IL-6, and TNFα.

“Importantly, IFNγ, IL-6, and TNFα are considered to be the most relevant cytokines responsible for dosing toxicities observed in clinical studies with T-cell engaging molecules, which suggests that APVO436 could offer the potential for reduced toxicities compared to other CD123 x CD3 T-cell engagers at comparable or higher doses,” Dr Gross said.

She added that Aptevo is planning to launch a phase 1 trial of APVO436 in patients with AML and myelodysplastic syndromes later this year.

Henrique Orlandi Mourao

CHICAGO—The bispecific antibody APVO436 has demonstrated robust T-cell activation with limited cytokine release in acute myeloid leukemia (AML), according to researchers.

APVO436 binds CD123 and CD3 to redirect T-cell cytotoxicity against CD123-expressing tumor cells.

Researchers found that APVO436 induced T-cell cytotoxicity in AML cells in vitro and in mouse models.

In addition, levels of several cytokines were lower in experiments with APVO436 than in experiments with a comparator antibody.

These findings were presented in a poster at the AACR Annual Meeting 2018 (abstract 1786).

The research was conducted by employees of Aptevo Therapeutics Inc., the company developing APVO436.

“We are especially excited about these latest data for APVO436, which continue to show robust T-cell engagement and cytotoxic activity with reduced levels of cytokine release,” said Jane Gross, PhD, senior vice president and chief scientific officer for Aptevo.

Dr Gross and her colleagues found that APVO436 binds human CD123 and CD3-expressing cells and has “potent” target-specific activity against CD123-expressing AML cell lines (Molm-13 and KG-1a).

In addition, APVO436 induced endogenous T-cell activation and proliferation, accompanied by depletion of CD123-expressing cells, in samples from AML patients and healthy donors.

T cells from these cultures (both AML and non-AML) were expanded and co-cultured with Molm-13 cells and APVO436 or a control antibody. Again, the researchers observed “potent” cytotoxic activity in the presence of APVO436.

Dr Gross and her colleagues also tested APVO436, co-administered with human T cells, in mice with established disseminated Molm-13 tumors. The treatment resulted in a “rapid and significant” reduction in skeletal tumor burden.

Finally, the team compared APVO436 with an Aptevo-generated version of MGD006, a CD123 x CD3 dual-affinity re-targeting molecule being developed by Macrogenics, Inc.

The researchers took purified T cells from healthy donors and cultured them with Molm-13 cells, as well as APVO436, Aptevo’s version of MGD006, and a control antibody.

Both APVO436 and Aptevo’s version of MGD006 were effective at stimulating a tumor-directed immune response, inducing comparable levels of T-cell activation, proliferation, and cytotoxicity.

However, APVO436 induced lower levels of several cytokines—including IFNγ, IL-2, IL-6, and TNFα.

“Importantly, IFNγ, IL-6, and TNFα are considered to be the most relevant cytokines responsible for dosing toxicities observed in clinical studies with T-cell engaging molecules, which suggests that APVO436 could offer the potential for reduced toxicities compared to other CD123 x CD3 T-cell engagers at comparable or higher doses,” Dr Gross said.

She added that Aptevo is planning to launch a phase 1 trial of APVO436 in patients with AML and myelodysplastic syndromes later this year.

NEWPORT BEACH, CALIF. – Adding pembrolizumab after high-dose cytarabine in patients with relapsed or refractory acute myeloid leukemia (AML) appears safe and feasible and shows promising efficacy, according to early results from a multicenter phase 2 study.

The overall response rate to this novel treatment approach in 19 evaluable patients (of 20 enrolled to date) was 42%, with 7 patients (37%) achieving a complete response or complete response with incomplete blood count recovery, and 1 (5%) achieving a partial response, reported Joshua Zeidner, MD, in a poster at the Acute Leukemia Forum of Hemedicus.

Sharon Worcester/MDedge News

Preliminary analyses in the first six patients, including three with complete response and three nonresponders, showed increased posttreatment diversity of the T-cell receptor repertoire versus baseline in peripheral blood CD8+ T cells in the complete response patients, compared with nonresponders. This suggests that T-cell diversity at baseline is a promising biomarker for programmed death-1 (PD-1) blockade response, Dr. Zeidner noted.

PD-1 suppresses immune activation, and the PD-1 pathway is exploited by AML cells to evade immune surveillance, Dr. Zeidner explained. PD-1 blockade has been shown to have antileukemic effects in vivo, there is expression of multiple coinhibitory receptors in AML patients at the time of diagnosis (that persists in refractory AML), and the ligand for PD-1 is up-regulated on AML blasts, particularly in relapsed/refractory disease, he added.

He and his colleagues hypothesized that targeting PD-1 with pembrolizumab after high-dose cytarabine (HiDAC) salvage chemotherapy would stimulate a T cell–mediated antileukemic immune response and lead to improved efficacy in patients with relapsed or refractory AML.

The ongoing study, with planned enrollment of 37 patients, includes patients aged 18-70 years with relapsed/refractory AML (median age of first 20 enrolled is 54 years). Those under age 60 years receive 2 g/m² of intravenous HiDAC every 12 hours on days 1-5, and those over age 60 years receive 1.5 g/m² every 12 hours on days 1-5. In both age groups, this is followed by intravenous pembrolizumab given at 200 mg on day 14.

Overall responders receive maintenance phase intravenous pembrolizumab at 200 mg every 3 weeks for up to 2 years until relapse or progression. Patients are allowed to proceed to stem cell transplant before or after the maintenance phase.

A number of correlative studies, including serial peripheral blood and bone marrow flow cytometry and T-cell receptor clonality studies, also are being conducted to look for predictive biomarkers of response, Dr. Zeidner said.

The study population to date is a relatively young, very-high-risk subgroup of AML patients; European LeukemiaNet-2017 genetic risk status was favorable in only 3 of the first 20 patients (15%), intermediate in 7 (35%), and adverse in 10 (50%). Treatment has been well tolerated; toxicities have been rare and manageable. “Overall, there have been no unexpected toxicities,” he said.

The most common overall toxicities included febrile neutropenia in 70% of patients; transaminitis (including one grade 3 case) in 50%, hyperbilirubinemia in 35%, and fatigue, increased alkaline phosphatase, and rash in 25% each.

Novel therapies for relapsed/refractory AML are urgently needed, and these early results demonstrated the safety and feasibility of adding pembrolizumab after HiDAC chemotherapy in relapsed/refractory AML patients. The preliminary finding that broadening of the immune repertoire, which may occur via increasing T-cell responses beyond endogenous viral responses, was associated with complete response was particularly encouraging, Dr. Zeidner said. The investigators hope to determine predictors of response to immune checkpoint blockade in AML through a comprehensive immune biomarker discovery approach, he added.

This study was funded by Merck. Dr. Zeidner reported having no financial disclosures. The Acute Leukemia Forum is held by Hemedicus, which is owned by the same company as this news organization.

[email protected]

SOURCE: Zeidner J et al. ALF 2018, Poster Session.

NEWPORT BEACH, CALIF. – Adding pembrolizumab after high-dose cytarabine in patients with relapsed or refractory acute myeloid leukemia (AML) appears safe and feasible and shows promising efficacy, according to early results from a multicenter phase 2 study.

The overall response rate to this novel treatment approach in 19 evaluable patients (of 20 enrolled to date) was 42%, with 7 patients (37%) achieving a complete response or complete response with incomplete blood count recovery, and 1 (5%) achieving a partial response, reported Joshua Zeidner, MD, in a poster at the Acute Leukemia Forum of Hemedicus.

Sharon Worcester/MDedge News

Preliminary analyses in the first six patients, including three with complete response and three nonresponders, showed increased posttreatment diversity of the T-cell receptor repertoire versus baseline in peripheral blood CD8+ T cells in the complete response patients, compared with nonresponders. This suggests that T-cell diversity at baseline is a promising biomarker for programmed death-1 (PD-1) blockade response, Dr. Zeidner noted.

PD-1 suppresses immune activation, and the PD-1 pathway is exploited by AML cells to evade immune surveillance, Dr. Zeidner explained. PD-1 blockade has been shown to have antileukemic effects in vivo, there is expression of multiple coinhibitory receptors in AML patients at the time of diagnosis (that persists in refractory AML), and the ligand for PD-1 is up-regulated on AML blasts, particularly in relapsed/refractory disease, he added.

He and his colleagues hypothesized that targeting PD-1 with pembrolizumab after high-dose cytarabine (HiDAC) salvage chemotherapy would stimulate a T cell–mediated antileukemic immune response and lead to improved efficacy in patients with relapsed or refractory AML.

The ongoing study, with planned enrollment of 37 patients, includes patients aged 18-70 years with relapsed/refractory AML (median age of first 20 enrolled is 54 years). Those under age 60 years receive 2 g/m² of intravenous HiDAC every 12 hours on days 1-5, and those over age 60 years receive 1.5 g/m² every 12 hours on days 1-5. In both age groups, this is followed by intravenous pembrolizumab given at 200 mg on day 14.

Overall responders receive maintenance phase intravenous pembrolizumab at 200 mg every 3 weeks for up to 2 years until relapse or progression. Patients are allowed to proceed to stem cell transplant before or after the maintenance phase.

A number of correlative studies, including serial peripheral blood and bone marrow flow cytometry and T-cell receptor clonality studies, also are being conducted to look for predictive biomarkers of response, Dr. Zeidner said.

The study population to date is a relatively young, very-high-risk subgroup of AML patients; European LeukemiaNet-2017 genetic risk status was favorable in only 3 of the first 20 patients (15%), intermediate in 7 (35%), and adverse in 10 (50%). Treatment has been well tolerated; toxicities have been rare and manageable. “Overall, there have been no unexpected toxicities,” he said.

The most common overall toxicities included febrile neutropenia in 70% of patients; transaminitis (including one grade 3 case) in 50%, hyperbilirubinemia in 35%, and fatigue, increased alkaline phosphatase, and rash in 25% each.

Novel therapies for relapsed/refractory AML are urgently needed, and these early results demonstrated the safety and feasibility of adding pembrolizumab after HiDAC chemotherapy in relapsed/refractory AML patients. The preliminary finding that broadening of the immune repertoire, which may occur via increasing T-cell responses beyond endogenous viral responses, was associated with complete response was particularly encouraging, Dr. Zeidner said. The investigators hope to determine predictors of response to immune checkpoint blockade in AML through a comprehensive immune biomarker discovery approach, he added.

This study was funded by Merck. Dr. Zeidner reported having no financial disclosures. The Acute Leukemia Forum is held by Hemedicus, which is owned by the same company as this news organization.

[email protected]

SOURCE: Zeidner J et al. ALF 2018, Poster Session.

NEWPORT BEACH, CALIF. – Adding pembrolizumab after high-dose cytarabine in patients with relapsed or refractory acute myeloid leukemia (AML) appears safe and feasible and shows promising efficacy, according to early results from a multicenter phase 2 study.

The overall response rate to this novel treatment approach in 19 evaluable patients (of 20 enrolled to date) was 42%, with 7 patients (37%) achieving a complete response or complete response with incomplete blood count recovery, and 1 (5%) achieving a partial response, reported Joshua Zeidner, MD, in a poster at the Acute Leukemia Forum of Hemedicus.

Sharon Worcester/MDedge News

Preliminary analyses in the first six patients, including three with complete response and three nonresponders, showed increased posttreatment diversity of the T-cell receptor repertoire versus baseline in peripheral blood CD8+ T cells in the complete response patients, compared with nonresponders. This suggests that T-cell diversity at baseline is a promising biomarker for programmed death-1 (PD-1) blockade response, Dr. Zeidner noted.

PD-1 suppresses immune activation, and the PD-1 pathway is exploited by AML cells to evade immune surveillance, Dr. Zeidner explained. PD-1 blockade has been shown to have antileukemic effects in vivo, there is expression of multiple coinhibitory receptors in AML patients at the time of diagnosis (that persists in refractory AML), and the ligand for PD-1 is up-regulated on AML blasts, particularly in relapsed/refractory disease, he added.

He and his colleagues hypothesized that targeting PD-1 with pembrolizumab after high-dose cytarabine (HiDAC) salvage chemotherapy would stimulate a T cell–mediated antileukemic immune response and lead to improved efficacy in patients with relapsed or refractory AML.

The ongoing study, with planned enrollment of 37 patients, includes patients aged 18-70 years with relapsed/refractory AML (median age of first 20 enrolled is 54 years). Those under age 60 years receive 2 g/m² of intravenous HiDAC every 12 hours on days 1-5, and those over age 60 years receive 1.5 g/m² every 12 hours on days 1-5. In both age groups, this is followed by intravenous pembrolizumab given at 200 mg on day 14.

Overall responders receive maintenance phase intravenous pembrolizumab at 200 mg every 3 weeks for up to 2 years until relapse or progression. Patients are allowed to proceed to stem cell transplant before or after the maintenance phase.

A number of correlative studies, including serial peripheral blood and bone marrow flow cytometry and T-cell receptor clonality studies, also are being conducted to look for predictive biomarkers of response, Dr. Zeidner said.

The study population to date is a relatively young, very-high-risk subgroup of AML patients; European LeukemiaNet-2017 genetic risk status was favorable in only 3 of the first 20 patients (15%), intermediate in 7 (35%), and adverse in 10 (50%). Treatment has been well tolerated; toxicities have been rare and manageable. “Overall, there have been no unexpected toxicities,” he said.

The most common overall toxicities included febrile neutropenia in 70% of patients; transaminitis (including one grade 3 case) in 50%, hyperbilirubinemia in 35%, and fatigue, increased alkaline phosphatase, and rash in 25% each.

Novel therapies for relapsed/refractory AML are urgently needed, and these early results demonstrated the safety and feasibility of adding pembrolizumab after HiDAC chemotherapy in relapsed/refractory AML patients. The preliminary finding that broadening of the immune repertoire, which may occur via increasing T-cell responses beyond endogenous viral responses, was associated with complete response was particularly encouraging, Dr. Zeidner said. The investigators hope to determine predictors of response to immune checkpoint blockade in AML through a comprehensive immune biomarker discovery approach, he added.

This study was funded by Merck. Dr. Zeidner reported having no financial disclosures. The Acute Leukemia Forum is held by Hemedicus, which is owned by the same company as this news organization.

[email protected]

SOURCE: Zeidner J et al. ALF 2018, Poster Session.

For patients with relapsed or refractory chronic lymphocytic leukemia despite therapy with idelalisib (Zydelig), venetoclax (Venclexta) was associated with relatively high overall response and progression-free survival rates, results of a phase 2 study show.

Among 36 patients with relapsed/refractory CLL who had received idelalisib as their most recent B-cell receptor pathway inhibitor (BCRi), the overall response rate (ORR) was 67%, and median progression-free and overall survival (PFS and OS) had not been reached after 14 months of follow-up, reported Steven Coutre, MD, of Stanford (Calif.) University, and his colleagues.

“[V]enetoclax monotherapy is active and well-tolerated in patients with CLL progression after therapy with idelalisib, including a significant number of patients who also received prior therapy with ibrutinib [Imbruvica]. These results from the first prospective trial in this high-risk population provide evidence that venetoclax should be considered as a treatment option for such patients,” the investigators wrote. The report was published in Blood.

In clinical trials with idelalisib, approximately one-third of patients with CLL experienced disease progression on therapy, and other patients had to discontinue the drug, an inhibitor of the delta isoform of phosphoinositide 3-kinase (PI3K), because of toxicities, the investigators noted.

“The optimal treatment of patients with CLL progressing after idelalisib has not been well characterized,” they wrote. “Outcomes in patients who discontinued idelalisib treatment early are poor, with one retrospective analysis reporting a median overall survival (OS) after idelalisib discontinuation of approximately 2 months (range, 0-10 months).”

Venetoclax, an inhibitor of the apoptotic BCL-2 protein, has been shown to have activity against CLL, including in patients with high-risk features such as the chromosome 17p deletion (del17p), prompting the investigators to evaluate it as a follow-on in patients with relapsed/refractory CLL treated with a B-cell receptor pathway inhibitor.

They reported on the idelalisib cohort in a phase 2 trial in which patients with CLL that progressed on either idelalisib or ibrutinib were subsequently treated with venetoclax. The patients in this analysis included those treated with idelalisib in the main study cohort or an expansion cohort.

Patients were started on venetoclax 20 mg daily, followed by weekly dose escalations to a target of 400 mg daily by week 5, or to a maximum of 600 mg for patients who did not have a response by the week 12 assessment.

The overall response rate – the primary efficacy endpoint – was 67%. There were two complete remissions (CR) and one CR with incomplete bone marrow recovery. The remaining 21 patients with responses had partial responses.

At a median of 14 months of follow-up, neither median PFS, duration of response, or OS had been reached.

The investigator-estimated 12-month PFS rate was 79%.

The most common grade 3 or 4 adverse events were neutropenia in 50% of patients, thrombocytopenia in 25%, and anemia in 17%. There were no cases of clinical tumor lysis syndrome, which has been known to occur when venetoclax is initiated at full dose without a ramp-up.

The most common adverse events of any grade included neutropenia, diarrhea, upper respiratory tract infection, thrombocytopenia, nausea, fatigue, cough, rash, and anemia.

“The low number of CRs reported at the time of analysis may be a result of the follow-up time, particularly for patients in the expansion cohort, as other clinical studies with venetoclax report CR occurring after 1 year on therapy. Patients with prior ibrutinib exposure who had progressed on idelalisib as their most recent therapy before study entry had similar efficacy results,” the investigators wrote.

Genentech and AbbVie funded the study. Dr. Coutre is an advisory board member for both companies and others, and receives institutional funding from AbbVie and others. Multiple coauthors disclosed financial relationships with AbbVie, Genentech, or both, as well as other companies.

SOURCE: Coutre S et al. Blood. 2018;131(15):1704-11.

For patients with relapsed or refractory chronic lymphocytic leukemia despite therapy with idelalisib (Zydelig), venetoclax (Venclexta) was associated with relatively high overall response and progression-free survival rates, results of a phase 2 study show.

Among 36 patients with relapsed/refractory CLL who had received idelalisib as their most recent B-cell receptor pathway inhibitor (BCRi), the overall response rate (ORR) was 67%, and median progression-free and overall survival (PFS and OS) had not been reached after 14 months of follow-up, reported Steven Coutre, MD, of Stanford (Calif.) University, and his colleagues.

“[V]enetoclax monotherapy is active and well-tolerated in patients with CLL progression after therapy with idelalisib, including a significant number of patients who also received prior therapy with ibrutinib [Imbruvica]. These results from the first prospective trial in this high-risk population provide evidence that venetoclax should be considered as a treatment option for such patients,” the investigators wrote. The report was published in Blood.

In clinical trials with idelalisib, approximately one-third of patients with CLL experienced disease progression on therapy, and other patients had to discontinue the drug, an inhibitor of the delta isoform of phosphoinositide 3-kinase (PI3K), because of toxicities, the investigators noted.

“The optimal treatment of patients with CLL progressing after idelalisib has not been well characterized,” they wrote. “Outcomes in patients who discontinued idelalisib treatment early are poor, with one retrospective analysis reporting a median overall survival (OS) after idelalisib discontinuation of approximately 2 months (range, 0-10 months).”

Venetoclax, an inhibitor of the apoptotic BCL-2 protein, has been shown to have activity against CLL, including in patients with high-risk features such as the chromosome 17p deletion (del17p), prompting the investigators to evaluate it as a follow-on in patients with relapsed/refractory CLL treated with a B-cell receptor pathway inhibitor.

They reported on the idelalisib cohort in a phase 2 trial in which patients with CLL that progressed on either idelalisib or ibrutinib were subsequently treated with venetoclax. The patients in this analysis included those treated with idelalisib in the main study cohort or an expansion cohort.

Patients were started on venetoclax 20 mg daily, followed by weekly dose escalations to a target of 400 mg daily by week 5, or to a maximum of 600 mg for patients who did not have a response by the week 12 assessment.

The overall response rate – the primary efficacy endpoint – was 67%. There were two complete remissions (CR) and one CR with incomplete bone marrow recovery. The remaining 21 patients with responses had partial responses.

At a median of 14 months of follow-up, neither median PFS, duration of response, or OS had been reached.

The investigator-estimated 12-month PFS rate was 79%.

The most common grade 3 or 4 adverse events were neutropenia in 50% of patients, thrombocytopenia in 25%, and anemia in 17%. There were no cases of clinical tumor lysis syndrome, which has been known to occur when venetoclax is initiated at full dose without a ramp-up.

The most common adverse events of any grade included neutropenia, diarrhea, upper respiratory tract infection, thrombocytopenia, nausea, fatigue, cough, rash, and anemia.

“The low number of CRs reported at the time of analysis may be a result of the follow-up time, particularly for patients in the expansion cohort, as other clinical studies with venetoclax report CR occurring after 1 year on therapy. Patients with prior ibrutinib exposure who had progressed on idelalisib as their most recent therapy before study entry had similar efficacy results,” the investigators wrote.

Genentech and AbbVie funded the study. Dr. Coutre is an advisory board member for both companies and others, and receives institutional funding from AbbVie and others. Multiple coauthors disclosed financial relationships with AbbVie, Genentech, or both, as well as other companies.

SOURCE: Coutre S et al. Blood. 2018;131(15):1704-11.

For patients with relapsed or refractory chronic lymphocytic leukemia despite therapy with idelalisib (Zydelig), venetoclax (Venclexta) was associated with relatively high overall response and progression-free survival rates, results of a phase 2 study show.

Among 36 patients with relapsed/refractory CLL who had received idelalisib as their most recent B-cell receptor pathway inhibitor (BCRi), the overall response rate (ORR) was 67%, and median progression-free and overall survival (PFS and OS) had not been reached after 14 months of follow-up, reported Steven Coutre, MD, of Stanford (Calif.) University, and his colleagues.

“[V]enetoclax monotherapy is active and well-tolerated in patients with CLL progression after therapy with idelalisib, including a significant number of patients who also received prior therapy with ibrutinib [Imbruvica]. These results from the first prospective trial in this high-risk population provide evidence that venetoclax should be considered as a treatment option for such patients,” the investigators wrote. The report was published in Blood.

In clinical trials with idelalisib, approximately one-third of patients with CLL experienced disease progression on therapy, and other patients had to discontinue the drug, an inhibitor of the delta isoform of phosphoinositide 3-kinase (PI3K), because of toxicities, the investigators noted.

“The optimal treatment of patients with CLL progressing after idelalisib has not been well characterized,” they wrote. “Outcomes in patients who discontinued idelalisib treatment early are poor, with one retrospective analysis reporting a median overall survival (OS) after idelalisib discontinuation of approximately 2 months (range, 0-10 months).”

Venetoclax, an inhibitor of the apoptotic BCL-2 protein, has been shown to have activity against CLL, including in patients with high-risk features such as the chromosome 17p deletion (del17p), prompting the investigators to evaluate it as a follow-on in patients with relapsed/refractory CLL treated with a B-cell receptor pathway inhibitor.

They reported on the idelalisib cohort in a phase 2 trial in which patients with CLL that progressed on either idelalisib or ibrutinib were subsequently treated with venetoclax. The patients in this analysis included those treated with idelalisib in the main study cohort or an expansion cohort.

Patients were started on venetoclax 20 mg daily, followed by weekly dose escalations to a target of 400 mg daily by week 5, or to a maximum of 600 mg for patients who did not have a response by the week 12 assessment.

The overall response rate – the primary efficacy endpoint – was 67%. There were two complete remissions (CR) and one CR with incomplete bone marrow recovery. The remaining 21 patients with responses had partial responses.

At a median of 14 months of follow-up, neither median PFS, duration of response, or OS had been reached.

The investigator-estimated 12-month PFS rate was 79%.

The most common grade 3 or 4 adverse events were neutropenia in 50% of patients, thrombocytopenia in 25%, and anemia in 17%. There were no cases of clinical tumor lysis syndrome, which has been known to occur when venetoclax is initiated at full dose without a ramp-up.

The most common adverse events of any grade included neutropenia, diarrhea, upper respiratory tract infection, thrombocytopenia, nausea, fatigue, cough, rash, and anemia.

“The low number of CRs reported at the time of analysis may be a result of the follow-up time, particularly for patients in the expansion cohort, as other clinical studies with venetoclax report CR occurring after 1 year on therapy. Patients with prior ibrutinib exposure who had progressed on idelalisib as their most recent therapy before study entry had similar efficacy results,” the investigators wrote.

Genentech and AbbVie funded the study. Dr. Coutre is an advisory board member for both companies and others, and receives institutional funding from AbbVie and others. Multiple coauthors disclosed financial relationships with AbbVie, Genentech, or both, as well as other companies.

SOURCE: Coutre S et al. Blood. 2018;131(15):1704-11.

In patients with multiple myeloma who had already undergone multiple lines of therapy, the combination of ibrutinib and carfilzomib with or without dexamethasone produced a favorable rate of response and progression-free survival.

Ibrutinib and carfilzomib combination therapy was also associated with manageable safety in the phase 1 results of the ongoing study, investigators wrote in the journal Leukemia & Lymphoma.

Nephron/Wikimedia Commons

SOURCE: Chari A et al. Leuk Lymphoma. 2018 Apr 4. doi: 10.1080/10428194.2018.1443337.

In patients with multiple myeloma who had already undergone multiple lines of therapy, the combination of ibrutinib and carfilzomib with or without dexamethasone produced a favorable rate of response and progression-free survival.

Ibrutinib and carfilzomib combination therapy was also associated with manageable safety in the phase 1 results of the ongoing study, investigators wrote in the journal Leukemia & Lymphoma.

Nephron/Wikimedia Commons

SOURCE: Chari A et al. Leuk Lymphoma. 2018 Apr 4. doi: 10.1080/10428194.2018.1443337.

In patients with multiple myeloma who had already undergone multiple lines of therapy, the combination of ibrutinib and carfilzomib with or without dexamethasone produced a favorable rate of response and progression-free survival.

Ibrutinib and carfilzomib combination therapy was also associated with manageable safety in the phase 1 results of the ongoing study, investigators wrote in the journal Leukemia & Lymphoma.

Nephron/Wikimedia Commons

SOURCE: Chari A et al. Leuk Lymphoma. 2018 Apr 4. doi: 10.1080/10428194.2018.1443337.

NEWPORT BEACH, CALIF. – Response and survival rates are similar with 5- and 10-day dosing of decitabine in poor-risk older adults with previously untreated acute myeloid leukemia, according to findings from a randomized phase 2 trial.

The overall response rates in 25 patients randomized to receive 5 days of decitabine and 40 patients randomized to receive 10 days of decitabine were 44% and 38%, respectively. Complete response rates were 28% and 30%, respectively, and the median number of cycles to best response was two in both arms, Nicholas J. Short, MD, reported in a poster at the Acute Leukemia Forum of Hemedicus.

Sharon Worcester/MDedge News

Patients received intravenous decitabine at a dose of 20 mg/m² for the assigned duration of either 5 or 10 consecutive days for the first three cycles of induction, and those who responded to treatment received additional consolidation cycles every 4-8 weeks for up to 24 total cycles. Patients in the 10-day arm were switched to 5-day dosing after achieving complete response or complete response with incomplete blood count recovery.

The groups were well balanced with respect to baseline characteristics and the imbalance in patient numbers in the arms was mainly because of adaptive randomization; the 10-day patients had better responses during the early part of the study, Dr. Short explained.

None of the patients underwent allogeneic stem cell transplantation, he added.

Older patients with acute AML often have poor tolerance for intensive chemotherapy, but decitabine has been shown to improve survival when compared with supportive care or low-dose cytarabine in these patients. However, while some single-arm studies have suggested that 5- and 10-day dosing may result in similar outcomes, and another suggested that 10-day dosing may be superior in TP53-mutated AML, no studies have directly compared 5- and 10-day dosing, he said.

“In this relatively poor-risk cohort of older adults with newly diagnosed AML, decitabine for 5 and 10 days resulted in similar response rates, survival, and early mortality,” he concluded.

This study was funded by a University of Texas MD Anderson Cancer Center support grant. Dr. Short reported having no financial disclosures.

The Acute Leukemia Forum is held by Hemedicus, which is owned by the same company as this news organization.

[email protected]

SOURCE: Short NJ et al. ALF 2018, Poster Session.

NEWPORT BEACH, CALIF. – Response and survival rates are similar with 5- and 10-day dosing of decitabine in poor-risk older adults with previously untreated acute myeloid leukemia, according to findings from a randomized phase 2 trial.

The overall response rates in 25 patients randomized to receive 5 days of decitabine and 40 patients randomized to receive 10 days of decitabine were 44% and 38%, respectively. Complete response rates were 28% and 30%, respectively, and the median number of cycles to best response was two in both arms, Nicholas J. Short, MD, reported in a poster at the Acute Leukemia Forum of Hemedicus.

Sharon Worcester/MDedge News

Patients received intravenous decitabine at a dose of 20 mg/m² for the assigned duration of either 5 or 10 consecutive days for the first three cycles of induction, and those who responded to treatment received additional consolidation cycles every 4-8 weeks for up to 24 total cycles. Patients in the 10-day arm were switched to 5-day dosing after achieving complete response or complete response with incomplete blood count recovery.

The groups were well balanced with respect to baseline characteristics and the imbalance in patient numbers in the arms was mainly because of adaptive randomization; the 10-day patients had better responses during the early part of the study, Dr. Short explained.

None of the patients underwent allogeneic stem cell transplantation, he added.

Older patients with acute AML often have poor tolerance for intensive chemotherapy, but decitabine has been shown to improve survival when compared with supportive care or low-dose cytarabine in these patients. However, while some single-arm studies have suggested that 5- and 10-day dosing may result in similar outcomes, and another suggested that 10-day dosing may be superior in TP53-mutated AML, no studies have directly compared 5- and 10-day dosing, he said.

“In this relatively poor-risk cohort of older adults with newly diagnosed AML, decitabine for 5 and 10 days resulted in similar response rates, survival, and early mortality,” he concluded.

This study was funded by a University of Texas MD Anderson Cancer Center support grant. Dr. Short reported having no financial disclosures.

The Acute Leukemia Forum is held by Hemedicus, which is owned by the same company as this news organization.

[email protected]

SOURCE: Short NJ et al. ALF 2018, Poster Session.

NEWPORT BEACH, CALIF. – Response and survival rates are similar with 5- and 10-day dosing of decitabine in poor-risk older adults with previously untreated acute myeloid leukemia, according to findings from a randomized phase 2 trial.

The overall response rates in 25 patients randomized to receive 5 days of decitabine and 40 patients randomized to receive 10 days of decitabine were 44% and 38%, respectively. Complete response rates were 28% and 30%, respectively, and the median number of cycles to best response was two in both arms, Nicholas J. Short, MD, reported in a poster at the Acute Leukemia Forum of Hemedicus.

Sharon Worcester/MDedge News

Patients received intravenous decitabine at a dose of 20 mg/m² for the assigned duration of either 5 or 10 consecutive days for the first three cycles of induction, and those who responded to treatment received additional consolidation cycles every 4-8 weeks for up to 24 total cycles. Patients in the 10-day arm were switched to 5-day dosing after achieving complete response or complete response with incomplete blood count recovery.

The groups were well balanced with respect to baseline characteristics and the imbalance in patient numbers in the arms was mainly because of adaptive randomization; the 10-day patients had better responses during the early part of the study, Dr. Short explained.

None of the patients underwent allogeneic stem cell transplantation, he added.

Older patients with acute AML often have poor tolerance for intensive chemotherapy, but decitabine has been shown to improve survival when compared with supportive care or low-dose cytarabine in these patients. However, while some single-arm studies have suggested that 5- and 10-day dosing may result in similar outcomes, and another suggested that 10-day dosing may be superior in TP53-mutated AML, no studies have directly compared 5- and 10-day dosing, he said.

“In this relatively poor-risk cohort of older adults with newly diagnosed AML, decitabine for 5 and 10 days resulted in similar response rates, survival, and early mortality,” he concluded.

This study was funded by a University of Texas MD Anderson Cancer Center support grant. Dr. Short reported having no financial disclosures.

The Acute Leukemia Forum is held by Hemedicus, which is owned by the same company as this news organization.

[email protected]

SOURCE: Short NJ et al. ALF 2018, Poster Session.

Patients with poor-risk acute myelogenous leukemia (AML) had promising rates of response and survival following treatment with a statin added to standard chemotherapy, researchers reported.

Pravastatin in combination with idarubicin and cytarabine had a 30% response rate in poor-risk AML patients, according to Anjali S. Advani, MD, of the Taussig Cancer Institute at the Cleveland Clinic, and her coauthors.

Although that response rate did not meet a prespecified threshold for statistical significance, results of the phase 2 study were nevertheless “encouraging” for a group of patients with unfavorable cytogenetics and poor-risk molecular mutations, the researchers wrote. The study was published in Leukemia Research.

The estimated median overall survival was 4.1 months in the phase 2 trial, known as SWOG S0919. About one-quarter of the patients were able to proceed to allogeneic hematopoietic stem cell transplant, and for that group, median overall survival was 27.1 months.

These findings appear to provide further support for the hypothesis that targeting the cholesterol pathway may be a promising approach in patients with AML.

Some previous investigations suggested that AML blasts overexpress genes for lipoprotein receptors and regulatory enzymes, while others showed that these cells import and synthesize cholesterol at levels higher than what is seen in normal progenitor cells. In addition, some AML patients have hypocholesterolemia that usually resolves when they achieve a complete remission.

“These observations suggest that AML cells may require high levels of cholesterol for their survival and that abnormalities in cholesterol homeostasis are necessary for AML cell survival,” the researchers wrote.

This led to a phase 1 trial of pravastatin plus idarubicin/cytarabine, followed by the phase 2 SWOG S0919 trial, which demonstrated a 75% rate of complete response (CR) or complete response with incomplete count recovery (CRi) for the regimen.

The SWOG S0919 study was amended to include the poor-risk AML patients described in the present study. That cohort of 46 patients had a CR/CRi of less than 6 months after their last induction regimen or refractory disease. Many had poor-risk cytogenetics (43%) or one of a number of poor-risk mutations, according to the study report.

Pravastatin, in addition to working on the cholesterol pathway in AML, may also have a therapeutic advantage in patients with FLT3 mutations. Three out of six patients with FLT3 mutations achieved CR/CRi, corroborating earlier preclinical studies and suggesting further study of this specific patient population would be worthwhile, the researchers noted.

The study was supported in part by the National Institutes of Health and Bristol-Myers Squibb. Dr. Advani reported having no financial disclosures but other study authors reported relationships with various pharmaceutical companies.

SOURCE: Advani AS et al. Leuk Res. 2018 Apr;67:17-20.

Patients with poor-risk acute myelogenous leukemia (AML) had promising rates of response and survival following treatment with a statin added to standard chemotherapy, researchers reported.

Pravastatin in combination with idarubicin and cytarabine had a 30% response rate in poor-risk AML patients, according to Anjali S. Advani, MD, of the Taussig Cancer Institute at the Cleveland Clinic, and her coauthors.

Although that response rate did not meet a prespecified threshold for statistical significance, results of the phase 2 study were nevertheless “encouraging” for a group of patients with unfavorable cytogenetics and poor-risk molecular mutations, the researchers wrote. The study was published in Leukemia Research.

The estimated median overall survival was 4.1 months in the phase 2 trial, known as SWOG S0919. About one-quarter of the patients were able to proceed to allogeneic hematopoietic stem cell transplant, and for that group, median overall survival was 27.1 months.

These findings appear to provide further support for the hypothesis that targeting the cholesterol pathway may be a promising approach in patients with AML.

Some previous investigations suggested that AML blasts overexpress genes for lipoprotein receptors and regulatory enzymes, while others showed that these cells import and synthesize cholesterol at levels higher than what is seen in normal progenitor cells. In addition, some AML patients have hypocholesterolemia that usually resolves when they achieve a complete remission.

“These observations suggest that AML cells may require high levels of cholesterol for their survival and that abnormalities in cholesterol homeostasis are necessary for AML cell survival,” the researchers wrote.

This led to a phase 1 trial of pravastatin plus idarubicin/cytarabine, followed by the phase 2 SWOG S0919 trial, which demonstrated a 75% rate of complete response (CR) or complete response with incomplete count recovery (CRi) for the regimen.

The SWOG S0919 study was amended to include the poor-risk AML patients described in the present study. That cohort of 46 patients had a CR/CRi of less than 6 months after their last induction regimen or refractory disease. Many had poor-risk cytogenetics (43%) or one of a number of poor-risk mutations, according to the study report.

Pravastatin, in addition to working on the cholesterol pathway in AML, may also have a therapeutic advantage in patients with FLT3 mutations. Three out of six patients with FLT3 mutations achieved CR/CRi, corroborating earlier preclinical studies and suggesting further study of this specific patient population would be worthwhile, the researchers noted.

The study was supported in part by the National Institutes of Health and Bristol-Myers Squibb. Dr. Advani reported having no financial disclosures but other study authors reported relationships with various pharmaceutical companies.

SOURCE: Advani AS et al. Leuk Res. 2018 Apr;67:17-20.

Patients with poor-risk acute myelogenous leukemia (AML) had promising rates of response and survival following treatment with a statin added to standard chemotherapy, researchers reported.

Pravastatin in combination with idarubicin and cytarabine had a 30% response rate in poor-risk AML patients, according to Anjali S. Advani, MD, of the Taussig Cancer Institute at the Cleveland Clinic, and her coauthors.

Although that response rate did not meet a prespecified threshold for statistical significance, results of the phase 2 study were nevertheless “encouraging” for a group of patients with unfavorable cytogenetics and poor-risk molecular mutations, the researchers wrote. The study was published in Leukemia Research.

The estimated median overall survival was 4.1 months in the phase 2 trial, known as SWOG S0919. About one-quarter of the patients were able to proceed to allogeneic hematopoietic stem cell transplant, and for that group, median overall survival was 27.1 months.

These findings appear to provide further support for the hypothesis that targeting the cholesterol pathway may be a promising approach in patients with AML.

Some previous investigations suggested that AML blasts overexpress genes for lipoprotein receptors and regulatory enzymes, while others showed that these cells import and synthesize cholesterol at levels higher than what is seen in normal progenitor cells. In addition, some AML patients have hypocholesterolemia that usually resolves when they achieve a complete remission.

“These observations suggest that AML cells may require high levels of cholesterol for their survival and that abnormalities in cholesterol homeostasis are necessary for AML cell survival,” the researchers wrote.

This led to a phase 1 trial of pravastatin plus idarubicin/cytarabine, followed by the phase 2 SWOG S0919 trial, which demonstrated a 75% rate of complete response (CR) or complete response with incomplete count recovery (CRi) for the regimen.

The SWOG S0919 study was amended to include the poor-risk AML patients described in the present study. That cohort of 46 patients had a CR/CRi of less than 6 months after their last induction regimen or refractory disease. Many had poor-risk cytogenetics (43%) or one of a number of poor-risk mutations, according to the study report.

Pravastatin, in addition to working on the cholesterol pathway in AML, may also have a therapeutic advantage in patients with FLT3 mutations. Three out of six patients with FLT3 mutations achieved CR/CRi, corroborating earlier preclinical studies and suggesting further study of this specific patient population would be worthwhile, the researchers noted.

The study was supported in part by the National Institutes of Health and Bristol-Myers Squibb. Dr. Advani reported having no financial disclosures but other study authors reported relationships with various pharmaceutical companies.

SOURCE: Advani AS et al. Leuk Res. 2018 Apr;67:17-20.

Photo by Rhoda Baer

Adding an experimental compound to chemotherapy is a “promising” treatment approach for certain patients with acute myeloid leukemia (AML), according to researchers.

They tested the compound, CPI-613, in combination with high-dose cytarabine and mitoxantrone in a phase 1 trial of patients with relapsed or refractory AML.

The combination produced similar response rates in the overall patient population (50%), patients age 60 and older (47%), and those with poor-risk cytogenetics (46%).

The most common grade 3/4 adverse events (AEs) were hematologic toxicities, and there was 1 fatal AE—hypotension.

Mortality rates in this trial were similar to those observed in historical controls treated with high-dose cytarabine, mitoxantrone, and asparaginase.

“These data are very encouraging, especially for patients 60 years of age or older who have historically done very poorly with this disease,” said Timothy Pardee, MD, PhD, a professor at Wake Forest Baptist Health in Winston-Salem, North Carolina, and chief medical officer of Rafael Pharmaceuticals, Inc., the company developing CPI-613.

Dr Pardee and his colleagues reported these results in Clinical Cancer Research.

The researchers noted that CPI-613 is designed to target mitochondrial metabolism in cancer cells, and preclinical research showed that CPI-613 sensitized AML cells to chemotherapy.

To investigate this further, the team tested CPI-613 in combination with high-dose cytarabine and mitoxantrone in the phase 1 trial. The study included 66 patients with relapsed or refractory AML, as well as a patient with advanced-phase chronic myeloid leukemia (CML) who was mistakenly enrolled.

The patients’ median age was 60 (range, 21-79), and 54% were age 60 and older. Their median percentage of marrow blasts was 43%. Forty percent of patients had poor-risk cytogenetics, and 49% had intermediate-risk cytogenetics.

Most patients (72%) had no prior salvage therapy, 13% had 1 prior line of salvage, 10% had 2 prior lines, and 4% had more than 2. Thirty-one percent of patients had refractory disease.

Seven percent of patients had previously received high-dose cytarabine and mitoxantrone, and 25% had previous salvage including high-dose or intermediate-dose cytarabine.

Treatment

Patients received CPI-613, given over 2 hours, on days 1 to 5 of cycle 1. Doses ranged from 500 mg/m² to 2750 mg/m².

Starting on day 3, patients received 5 doses of cytarabine at 3 gm/m² (for patients younger than 60) or 1.5 gm/m² (for older patients) in 500 mL normal saline, over 3 hours, every 12 hours.

Patients also received 3 daily doses of mitoxantrone at 6 mg/m² in 50 mL normal saline, given over 15 minutes, after the first, third, and fifth doses of cytarabine.

Patients were initially assigned to receive 1 cycle of treatment. Those with at least 5% blasts after the first cycle could receive a second course—either a full course or a 3-day course. And patients who responded to the first course could receive up to 2 cycles of the 3-day course.

Safety

There were 2 dose-limiting toxicities when CPI-613 was given at the 2750 mg/m² dose. One of these toxicities was grade 3 diarrhea that didn’t respond to anti-diarrheals, and the other was grade 3 nausea that didn’t respond to antiemetics.

Because of these events, 2500 mg/m² was deemed the maximum-tolerated dose. However, the recommended phase 2 dose is 2000 mg/m².

The most common AEs—occurring in at least 50% of all patients who received CPI-613 (n=67)—included hemoglobin decrease (67%), hyperglycemia (67%), neutropenia (67%), thrombocytopenia (67%), hypomagnesemia (66%), leukopenia (66%), lymphopenia (66%), hypoalbuminemia (65%), hypokalemia (60%), hypocalcemia (57%), and diarrhea (55%).

All cases of neutropenia, thrombocytopenia, leukopenia, and lymphopenia were grade 3/4. Other common grade 3/4 AEs (occurring in at least 20% of patients) included hemoglobin decrease (62%), febrile neutropenia (28%), hypophosphatemia (24%), and hypokalemia (23%).

The only grade 5 AE was hypotension.

The mortality rate was 12% (n=8) at 30 days and 19% (n=13) at 60 days. The researchers said this was similar to the historical experience with high-dose cytarabine, mitoxantrone, and asparaginase. Mortality rates with this regimen were 13% at 30 days and 22% at 60 days.

Efficacy

Sixty-two patients were evaluable for response. Of the 5 patients who were not evaluable, 1 didn’t complete the first cycle of treatment, 1 was the CML patient, and 3 died before assessment.

The overall response rate was 50% (31/62). This included 26 patients with a complete response (CR) and 5 patients who had a CR with incomplete count recovery (CRi).

The rate of CR/CRi was 47% (15/32) in patients older than 60 years of age, 46% (11/24) in patients who had poor-risk cytogenetics, and 53% (8/15) when CPI-613 was given at the recommended phase 2 dose—2000 mg/m².

The median overall survival (OS) was 6.7 months for all evaluable patients and 13.2 months for patients who achieved a CR/CRi.

The median OS was 6.9 months for patients age 60 and older, which was not significantly different from the median OS in younger patients (P=0.9642).

This study was sponsored by Wake Forest University Health Sciences and the National Cancer Institute.

Photo by Rhoda Baer

Adding an experimental compound to chemotherapy is a “promising” treatment approach for certain patients with acute myeloid leukemia (AML), according to researchers.

They tested the compound, CPI-613, in combination with high-dose cytarabine and mitoxantrone in a phase 1 trial of patients with relapsed or refractory AML.

The combination produced similar response rates in the overall patient population (50%), patients age 60 and older (47%), and those with poor-risk cytogenetics (46%).

The most common grade 3/4 adverse events (AEs) were hematologic toxicities, and there was 1 fatal AE—hypotension.

Mortality rates in this trial were similar to those observed in historical controls treated with high-dose cytarabine, mitoxantrone, and asparaginase.

“These data are very encouraging, especially for patients 60 years of age or older who have historically done very poorly with this disease,” said Timothy Pardee, MD, PhD, a professor at Wake Forest Baptist Health in Winston-Salem, North Carolina, and chief medical officer of Rafael Pharmaceuticals, Inc., the company developing CPI-613.

Dr Pardee and his colleagues reported these results in Clinical Cancer Research.

The researchers noted that CPI-613 is designed to target mitochondrial metabolism in cancer cells, and preclinical research showed that CPI-613 sensitized AML cells to chemotherapy.

To investigate this further, the team tested CPI-613 in combination with high-dose cytarabine and mitoxantrone in the phase 1 trial. The study included 66 patients with relapsed or refractory AML, as well as a patient with advanced-phase chronic myeloid leukemia (CML) who was mistakenly enrolled.

The patients’ median age was 60 (range, 21-79), and 54% were age 60 and older. Their median percentage of marrow blasts was 43%. Forty percent of patients had poor-risk cytogenetics, and 49% had intermediate-risk cytogenetics.

Most patients (72%) had no prior salvage therapy, 13% had 1 prior line of salvage, 10% had 2 prior lines, and 4% had more than 2. Thirty-one percent of patients had refractory disease.

Seven percent of patients had previously received high-dose cytarabine and mitoxantrone, and 25% had previous salvage including high-dose or intermediate-dose cytarabine.

Treatment

Patients received CPI-613, given over 2 hours, on days 1 to 5 of cycle 1. Doses ranged from 500 mg/m² to 2750 mg/m².

Starting on day 3, patients received 5 doses of cytarabine at 3 gm/m² (for patients younger than 60) or 1.5 gm/m² (for older patients) in 500 mL normal saline, over 3 hours, every 12 hours.

Patients also received 3 daily doses of mitoxantrone at 6 mg/m² in 50 mL normal saline, given over 15 minutes, after the first, third, and fifth doses of cytarabine.

Patients were initially assigned to receive 1 cycle of treatment. Those with at least 5% blasts after the first cycle could receive a second course—either a full course or a 3-day course. And patients who responded to the first course could receive up to 2 cycles of the 3-day course.

Safety

There were 2 dose-limiting toxicities when CPI-613 was given at the 2750 mg/m² dose. One of these toxicities was grade 3 diarrhea that didn’t respond to anti-diarrheals, and the other was grade 3 nausea that didn’t respond to antiemetics.

Because of these events, 2500 mg/m² was deemed the maximum-tolerated dose. However, the recommended phase 2 dose is 2000 mg/m².

The most common AEs—occurring in at least 50% of all patients who received CPI-613 (n=67)—included hemoglobin decrease (67%), hyperglycemia (67%), neutropenia (67%), thrombocytopenia (67%), hypomagnesemia (66%), leukopenia (66%), lymphopenia (66%), hypoalbuminemia (65%), hypokalemia (60%), hypocalcemia (57%), and diarrhea (55%).

All cases of neutropenia, thrombocytopenia, leukopenia, and lymphopenia were grade 3/4. Other common grade 3/4 AEs (occurring in at least 20% of patients) included hemoglobin decrease (62%), febrile neutropenia (28%), hypophosphatemia (24%), and hypokalemia (23%).

The only grade 5 AE was hypotension.

The mortality rate was 12% (n=8) at 30 days and 19% (n=13) at 60 days. The researchers said this was similar to the historical experience with high-dose cytarabine, mitoxantrone, and asparaginase. Mortality rates with this regimen were 13% at 30 days and 22% at 60 days.

Efficacy

Sixty-two patients were evaluable for response. Of the 5 patients who were not evaluable, 1 didn’t complete the first cycle of treatment, 1 was the CML patient, and 3 died before assessment.

The overall response rate was 50% (31/62). This included 26 patients with a complete response (CR) and 5 patients who had a CR with incomplete count recovery (CRi).

The rate of CR/CRi was 47% (15/32) in patients older than 60 years of age, 46% (11/24) in patients who had poor-risk cytogenetics, and 53% (8/15) when CPI-613 was given at the recommended phase 2 dose—2000 mg/m².

The median overall survival (OS) was 6.7 months for all evaluable patients and 13.2 months for patients who achieved a CR/CRi.

The median OS was 6.9 months for patients age 60 and older, which was not significantly different from the median OS in younger patients (P=0.9642).

This study was sponsored by Wake Forest University Health Sciences and the National Cancer Institute.

Photo by Rhoda Baer

Adding an experimental compound to chemotherapy is a “promising” treatment approach for certain patients with acute myeloid leukemia (AML), according to researchers.

They tested the compound, CPI-613, in combination with high-dose cytarabine and mitoxantrone in a phase 1 trial of patients with relapsed or refractory AML.

The combination produced similar response rates in the overall patient population (50%), patients age 60 and older (47%), and those with poor-risk cytogenetics (46%).

The most common grade 3/4 adverse events (AEs) were hematologic toxicities, and there was 1 fatal AE—hypotension.

Mortality rates in this trial were similar to those observed in historical controls treated with high-dose cytarabine, mitoxantrone, and asparaginase.

“These data are very encouraging, especially for patients 60 years of age or older who have historically done very poorly with this disease,” said Timothy Pardee, MD, PhD, a professor at Wake Forest Baptist Health in Winston-Salem, North Carolina, and chief medical officer of Rafael Pharmaceuticals, Inc., the company developing CPI-613.

Dr Pardee and his colleagues reported these results in Clinical Cancer Research.

The researchers noted that CPI-613 is designed to target mitochondrial metabolism in cancer cells, and preclinical research showed that CPI-613 sensitized AML cells to chemotherapy.

To investigate this further, the team tested CPI-613 in combination with high-dose cytarabine and mitoxantrone in the phase 1 trial. The study included 66 patients with relapsed or refractory AML, as well as a patient with advanced-phase chronic myeloid leukemia (CML) who was mistakenly enrolled.

The patients’ median age was 60 (range, 21-79), and 54% were age 60 and older. Their median percentage of marrow blasts was 43%. Forty percent of patients had poor-risk cytogenetics, and 49% had intermediate-risk cytogenetics.

Most patients (72%) had no prior salvage therapy, 13% had 1 prior line of salvage, 10% had 2 prior lines, and 4% had more than 2. Thirty-one percent of patients had refractory disease.

Seven percent of patients had previously received high-dose cytarabine and mitoxantrone, and 25% had previous salvage including high-dose or intermediate-dose cytarabine.

Treatment

Patients received CPI-613, given over 2 hours, on days 1 to 5 of cycle 1. Doses ranged from 500 mg/m² to 2750 mg/m².

Starting on day 3, patients received 5 doses of cytarabine at 3 gm/m² (for patients younger than 60) or 1.5 gm/m² (for older patients) in 500 mL normal saline, over 3 hours, every 12 hours.

Patients also received 3 daily doses of mitoxantrone at 6 mg/m² in 50 mL normal saline, given over 15 minutes, after the first, third, and fifth doses of cytarabine.

Patients were initially assigned to receive 1 cycle of treatment. Those with at least 5% blasts after the first cycle could receive a second course—either a full course or a 3-day course. And patients who responded to the first course could receive up to 2 cycles of the 3-day course.

Safety

There were 2 dose-limiting toxicities when CPI-613 was given at the 2750 mg/m² dose. One of these toxicities was grade 3 diarrhea that didn’t respond to anti-diarrheals, and the other was grade 3 nausea that didn’t respond to antiemetics.

Because of these events, 2500 mg/m² was deemed the maximum-tolerated dose. However, the recommended phase 2 dose is 2000 mg/m².

The most common AEs—occurring in at least 50% of all patients who received CPI-613 (n=67)—included hemoglobin decrease (67%), hyperglycemia (67%), neutropenia (67%), thrombocytopenia (67%), hypomagnesemia (66%), leukopenia (66%), lymphopenia (66%), hypoalbuminemia (65%), hypokalemia (60%), hypocalcemia (57%), and diarrhea (55%).

All cases of neutropenia, thrombocytopenia, leukopenia, and lymphopenia were grade 3/4. Other common grade 3/4 AEs (occurring in at least 20% of patients) included hemoglobin decrease (62%), febrile neutropenia (28%), hypophosphatemia (24%), and hypokalemia (23%).

The only grade 5 AE was hypotension.

The mortality rate was 12% (n=8) at 30 days and 19% (n=13) at 60 days. The researchers said this was similar to the historical experience with high-dose cytarabine, mitoxantrone, and asparaginase. Mortality rates with this regimen were 13% at 30 days and 22% at 60 days.

Efficacy

Sixty-two patients were evaluable for response. Of the 5 patients who were not evaluable, 1 didn’t complete the first cycle of treatment, 1 was the CML patient, and 3 died before assessment.

The overall response rate was 50% (31/62). This included 26 patients with a complete response (CR) and 5 patients who had a CR with incomplete count recovery (CRi).

The rate of CR/CRi was 47% (15/32) in patients older than 60 years of age, 46% (11/24) in patients who had poor-risk cytogenetics, and 53% (8/15) when CPI-613 was given at the recommended phase 2 dose—2000 mg/m².

The median overall survival (OS) was 6.7 months for all evaluable patients and 13.2 months for patients who achieved a CR/CRi.

The median OS was 6.9 months for patients age 60 and older, which was not significantly different from the median OS in younger patients (P=0.9642).

This study was sponsored by Wake Forest University Health Sciences and the National Cancer Institute.

In this interview, Dr David Henry, MD, the Editor-in-Chief of JCSO, and David Steensma, MD, of the Dana-Farber Cancer Institute in Boston, talk about myelodysplasic syndromes, from diagnosis, evaluation, and etiologies, to therapy options and molecular sequencing.

Listen to the podcast below, or click on the PDF icon at the top of this introduction to read a transcript of the interview.​

In this interview, Dr David Henry, MD, the Editor-in-Chief of JCSO, and David Steensma, MD, of the Dana-Farber Cancer Institute in Boston, talk about myelodysplasic syndromes, from diagnosis, evaluation, and etiologies, to therapy options and molecular sequencing.

Listen to the podcast below, or click on the PDF icon at the top of this introduction to read a transcript of the interview.​

In this interview, Dr David Henry, MD, the Editor-in-Chief of JCSO, and David Steensma, MD, of the Dana-Farber Cancer Institute in Boston, talk about myelodysplasic syndromes, from diagnosis, evaluation, and etiologies, to therapy options and molecular sequencing.

Listen to the podcast below, or click on the PDF icon at the top of this introduction to read a transcript of the interview.​

After treatment with blinatumomab, most patients with minimal residual disease–positive acute lymphoblastic leukemia (ALL) achieved complete MRD response, according to results of a single-arm phase 2 study.

Achieving complete MRD response was associated with significantly longer relapse-free and overall survival in the patients, who were already in hematologic complete remission, researchers reported in the journal Blood.

“Our results suggest that targeted treatment in early stages of MRD is a viable therapeutic strategy for patients with B-cell precursor ALL and that it should also be evaluated in other hematologic malignancies,” Nicola Gökbuget, MD, University Hospital, Frankfurt, Germany, and her coauthors wrote.

This is the first international multicenter study to specifically enroll MRD-positive ALL patients and evaluate them for an MRD-based primary outcome in a cohort of MRD-positive ALL patients, according to the authors.

Preemptively treating low but measurable disease in ALL in remission, instead of waiting for overt relapse, is a strategy that may prolong overall survival, Dr. Gökbuget and her colleagues said in describing the rationale for their study. While there is no standard therapy yet for ALL patients with detectable MRD after intensive chemotherapy, hematopoietic stem cell transplantation (HSCT) is recommended, based on data that it may improve outcomes in patients with persistent MRD. However, other studies suggest detectable MRD before HSCT is associated with higher relapse rates, and many patients relapse while waiting for HSCT, the researchers noted.

To test an MRD-directed treatment strategy, Dr. Gökbuget and colleagues at 46 centers in Europe and Russia conducted an open-label, single-arm, phase 2 study including 116 patients with B-cell precursor ALL in hematologic complete remission. Patients in the study received up to four cycles of blinatumomab, a bispecific, T cell–engager antibody construct that enables T cells to recognize and eliminate CD19-positive cells.

Of 113 evaluable patients, 88 (78%) achieved complete MRD response after one cycle, the primary end point of the study. Relapse-free survival at 18 months was estimated at 54% and median overall survival was 36.5 months in the subset of 110 patients with Philadelphia chromosome–negative ALL in hematologic remission.

SOURCE: Gökbuget N et al. Blood. 2018 Apr 5;131(14):1522-31.

After treatment with blinatumomab, most patients with minimal residual disease–positive acute lymphoblastic leukemia (ALL) achieved complete MRD response, according to results of a single-arm phase 2 study.

Achieving complete MRD response was associated with significantly longer relapse-free and overall survival in the patients, who were already in hematologic complete remission, researchers reported in the journal Blood.

“Our results suggest that targeted treatment in early stages of MRD is a viable therapeutic strategy for patients with B-cell precursor ALL and that it should also be evaluated in other hematologic malignancies,” Nicola Gökbuget, MD, University Hospital, Frankfurt, Germany, and her coauthors wrote.

This is the first international multicenter study to specifically enroll MRD-positive ALL patients and evaluate them for an MRD-based primary outcome in a cohort of MRD-positive ALL patients, according to the authors.

Preemptively treating low but measurable disease in ALL in remission, instead of waiting for overt relapse, is a strategy that may prolong overall survival, Dr. Gökbuget and her colleagues said in describing the rationale for their study. While there is no standard therapy yet for ALL patients with detectable MRD after intensive chemotherapy, hematopoietic stem cell transplantation (HSCT) is recommended, based on data that it may improve outcomes in patients with persistent MRD. However, other studies suggest detectable MRD before HSCT is associated with higher relapse rates, and many patients relapse while waiting for HSCT, the researchers noted.

To test an MRD-directed treatment strategy, Dr. Gökbuget and colleagues at 46 centers in Europe and Russia conducted an open-label, single-arm, phase 2 study including 116 patients with B-cell precursor ALL in hematologic complete remission. Patients in the study received up to four cycles of blinatumomab, a bispecific, T cell–engager antibody construct that enables T cells to recognize and eliminate CD19-positive cells.

Of 113 evaluable patients, 88 (78%) achieved complete MRD response after one cycle, the primary end point of the study. Relapse-free survival at 18 months was estimated at 54% and median overall survival was 36.5 months in the subset of 110 patients with Philadelphia chromosome–negative ALL in hematologic remission.

SOURCE: Gökbuget N et al. Blood. 2018 Apr 5;131(14):1522-31.

After treatment with blinatumomab, most patients with minimal residual disease–positive acute lymphoblastic leukemia (ALL) achieved complete MRD response, according to results of a single-arm phase 2 study.

Achieving complete MRD response was associated with significantly longer relapse-free and overall survival in the patients, who were already in hematologic complete remission, researchers reported in the journal Blood.

“Our results suggest that targeted treatment in early stages of MRD is a viable therapeutic strategy for patients with B-cell precursor ALL and that it should also be evaluated in other hematologic malignancies,” Nicola Gökbuget, MD, University Hospital, Frankfurt, Germany, and her coauthors wrote.

This is the first international multicenter study to specifically enroll MRD-positive ALL patients and evaluate them for an MRD-based primary outcome in a cohort of MRD-positive ALL patients, according to the authors.

Preemptively treating low but measurable disease in ALL in remission, instead of waiting for overt relapse, is a strategy that may prolong overall survival, Dr. Gökbuget and her colleagues said in describing the rationale for their study. While there is no standard therapy yet for ALL patients with detectable MRD after intensive chemotherapy, hematopoietic stem cell transplantation (HSCT) is recommended, based on data that it may improve outcomes in patients with persistent MRD. However, other studies suggest detectable MRD before HSCT is associated with higher relapse rates, and many patients relapse while waiting for HSCT, the researchers noted.

To test an MRD-directed treatment strategy, Dr. Gökbuget and colleagues at 46 centers in Europe and Russia conducted an open-label, single-arm, phase 2 study including 116 patients with B-cell precursor ALL in hematologic complete remission. Patients in the study received up to four cycles of blinatumomab, a bispecific, T cell–engager antibody construct that enables T cells to recognize and eliminate CD19-positive cells.

Of 113 evaluable patients, 88 (78%) achieved complete MRD response after one cycle, the primary end point of the study. Relapse-free survival at 18 months was estimated at 54% and median overall survival was 36.5 months in the subset of 110 patients with Philadelphia chromosome–negative ALL in hematologic remission.

SOURCE: Gökbuget N et al. Blood. 2018 Apr 5;131(14):1522-31.

Lab mouse

Preclinical results support clinical testing of an experimental agent in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), according to researchers.

The agent, ALRN-6924, was shown to combat AML and MDS by restoring activity of the tumor-suppressing protein p53.

ALRN-6924 exhibited antileukemic activity in AML cells and mouse models of the disease, as well as in a patient with MDS and excess leukemic blasts who received the drug on a compassionate-use basis.

These results, published in Science Translational Medicine, have led to a phase 1 trial of ALRN-6924 in patients with AML or MDS.

ALRN-6924 was developed by Aileron Therapeutics Inc., to target p53 by inhibiting 2 naturally occurring proteins, MDMX and MDM2. Overexpression of these proteins inactivates p53, allowing cancer cells to multiply unchecked.

In the current study, researchers set out to confirm ALRN-6924’s mechanism of action and determine the efficacy of the drug in AML/MDS. This work was supported, in part, by grants from Aileron Therapeutics Inc., and the National Institutes of Health.

The researchers did find that ALRN-6924 targets both MDMX and MDM2, blocking their interaction with p53 in AML cells.

The team said ALRN-6924 inhibited proliferation by inducing cell-cycle arrest and apoptosis in AML cell lines and AML patient cells, including leukemic stem cell-enriched populations.

“This is important because AML is driven by stem cells, and, if you don’t target stem cells, the disease will come back very quickly,” said study author Ulrich Steidl, MD, PhD, of Albert Einstein College of Medicine in Bronx, New York.

The researchers also found that ALRN-6924 greatly increased survival in a mouse model of AML. The median survival was 34 days in vehicle-treated control mice, 83 days in mice that received ALRN-6924 at 20 mg/kg twice a week, and 151 days in mice that received ALRN-6924 at 20 mg/kg three times a week.

“This is a very striking response,” Dr Steidl said. “Most experimental drugs for leukemia achieve an increase in survival of only a few days in these preclinical models. Even more importantly, ALRN-6924 effectively cured about 40% of the treated mice, meaning they were disease-free more than 1 year after treatment, essentially a lifetime for a mouse.”

Finally, the researchers assessed the effects of ALRN-6924 in a patient who had high-risk MDS with excess leukemic blasts.

The team found the p53 protein “was rapidly induced” in CD34+ leukemic blasts but not in healthy lymphocytes. And ALRN-6924 reduced the number of malignant cells circulating in the blood.

“This test was not designed to assess the efficacy of the drug in humans,” Dr Steidl noted. “That has to be done in a proper clinical trial. Our goal was to determine whether it can hit the desired target in human cells in a clinical setting, which it did in this individual.”

ALRN-6924 is a stapled alpha-helical peptide, a class of drugs whose helical structure is stabilized using hydrocarbon “staples.” The stapling prevents the peptides from being degraded by enzymes before reaching their intended target. ALRN-6924 is the first stapled peptide therapeutic to be tested in patients.

In the phase 1 trial (NCT02909972), researchers are testing ALRN-6924 in patients with relapsed/refractory AML or advanced MDS.

Lab mouse

Preclinical results support clinical testing of an experimental agent in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), according to researchers.

The agent, ALRN-6924, was shown to combat AML and MDS by restoring activity of the tumor-suppressing protein p53.

ALRN-6924 exhibited antileukemic activity in AML cells and mouse models of the disease, as well as in a patient with MDS and excess leukemic blasts who received the drug on a compassionate-use basis.

These results, published in Science Translational Medicine, have led to a phase 1 trial of ALRN-6924 in patients with AML or MDS.

ALRN-6924 was developed by Aileron Therapeutics Inc., to target p53 by inhibiting 2 naturally occurring proteins, MDMX and MDM2. Overexpression of these proteins inactivates p53, allowing cancer cells to multiply unchecked.

In the current study, researchers set out to confirm ALRN-6924’s mechanism of action and determine the efficacy of the drug in AML/MDS. This work was supported, in part, by grants from Aileron Therapeutics Inc., and the National Institutes of Health.

The researchers did find that ALRN-6924 targets both MDMX and MDM2, blocking their interaction with p53 in AML cells.

The team said ALRN-6924 inhibited proliferation by inducing cell-cycle arrest and apoptosis in AML cell lines and AML patient cells, including leukemic stem cell-enriched populations.

“This is important because AML is driven by stem cells, and, if you don’t target stem cells, the disease will come back very quickly,” said study author Ulrich Steidl, MD, PhD, of Albert Einstein College of Medicine in Bronx, New York.

The researchers also found that ALRN-6924 greatly increased survival in a mouse model of AML. The median survival was 34 days in vehicle-treated control mice, 83 days in mice that received ALRN-6924 at 20 mg/kg twice a week, and 151 days in mice that received ALRN-6924 at 20 mg/kg three times a week.

“This is a very striking response,” Dr Steidl said. “Most experimental drugs for leukemia achieve an increase in survival of only a few days in these preclinical models. Even more importantly, ALRN-6924 effectively cured about 40% of the treated mice, meaning they were disease-free more than 1 year after treatment, essentially a lifetime for a mouse.”

Finally, the researchers assessed the effects of ALRN-6924 in a patient who had high-risk MDS with excess leukemic blasts.

The team found the p53 protein “was rapidly induced” in CD34+ leukemic blasts but not in healthy lymphocytes. And ALRN-6924 reduced the number of malignant cells circulating in the blood.

“This test was not designed to assess the efficacy of the drug in humans,” Dr Steidl noted. “That has to be done in a proper clinical trial. Our goal was to determine whether it can hit the desired target in human cells in a clinical setting, which it did in this individual.”

ALRN-6924 is a stapled alpha-helical peptide, a class of drugs whose helical structure is stabilized using hydrocarbon “staples.” The stapling prevents the peptides from being degraded by enzymes before reaching their intended target. ALRN-6924 is the first stapled peptide therapeutic to be tested in patients.

In the phase 1 trial (NCT02909972), researchers are testing ALRN-6924 in patients with relapsed/refractory AML or advanced MDS.

Lab mouse

Preclinical results support clinical testing of an experimental agent in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), according to researchers.

The agent, ALRN-6924, was shown to combat AML and MDS by restoring activity of the tumor-suppressing protein p53.

ALRN-6924 exhibited antileukemic activity in AML cells and mouse models of the disease, as well as in a patient with MDS and excess leukemic blasts who received the drug on a compassionate-use basis.

These results, published in Science Translational Medicine, have led to a phase 1 trial of ALRN-6924 in patients with AML or MDS.

ALRN-6924 was developed by Aileron Therapeutics Inc., to target p53 by inhibiting 2 naturally occurring proteins, MDMX and MDM2. Overexpression of these proteins inactivates p53, allowing cancer cells to multiply unchecked.

In the current study, researchers set out to confirm ALRN-6924’s mechanism of action and determine the efficacy of the drug in AML/MDS. This work was supported, in part, by grants from Aileron Therapeutics Inc., and the National Institutes of Health.

The researchers did find that ALRN-6924 targets both MDMX and MDM2, blocking their interaction with p53 in AML cells.

The team said ALRN-6924 inhibited proliferation by inducing cell-cycle arrest and apoptosis in AML cell lines and AML patient cells, including leukemic stem cell-enriched populations.

“This is important because AML is driven by stem cells, and, if you don’t target stem cells, the disease will come back very quickly,” said study author Ulrich Steidl, MD, PhD, of Albert Einstein College of Medicine in Bronx, New York.

The researchers also found that ALRN-6924 greatly increased survival in a mouse model of AML. The median survival was 34 days in vehicle-treated control mice, 83 days in mice that received ALRN-6924 at 20 mg/kg twice a week, and 151 days in mice that received ALRN-6924 at 20 mg/kg three times a week.

“This is a very striking response,” Dr Steidl said. “Most experimental drugs for leukemia achieve an increase in survival of only a few days in these preclinical models. Even more importantly, ALRN-6924 effectively cured about 40% of the treated mice, meaning they were disease-free more than 1 year after treatment, essentially a lifetime for a mouse.”

Finally, the researchers assessed the effects of ALRN-6924 in a patient who had high-risk MDS with excess leukemic blasts.

The team found the p53 protein “was rapidly induced” in CD34+ leukemic blasts but not in healthy lymphocytes. And ALRN-6924 reduced the number of malignant cells circulating in the blood.

“This test was not designed to assess the efficacy of the drug in humans,” Dr Steidl noted. “That has to be done in a proper clinical trial. Our goal was to determine whether it can hit the desired target in human cells in a clinical setting, which it did in this individual.”

ALRN-6924 is a stapled alpha-helical peptide, a class of drugs whose helical structure is stabilized using hydrocarbon “staples.” The stapling prevents the peptides from being degraded by enzymes before reaching their intended target. ALRN-6924 is the first stapled peptide therapeutic to be tested in patients.

In the phase 1 trial (NCT02909972), researchers are testing ALRN-6924 in patients with relapsed/refractory AML or advanced MDS.