Acalabrutinib shows less off-target activity in mantle cell lymphoma

A new Bruton tyrosine kinase inhibitor has shown a high response rate and favorable safety profile in the treatment of patients with mantle cell lymphoma.

Researchers reported the results of an open-label, phase 2 study of oral acalabrutinib (100 mg, twice daily) in 124 patients with relapsed or refractory mantle cell lymphoma in The Lancet. Acalabrutinib (Calquence) received accelerated approval from the Food and Drug Administration in October 2017 for treatment of adults with mantle cell lymphoma who have received at least one prior therapy.

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib (Imbruvica), which was approved in 2013 for the treatment of mantle cell lymphoma, has been associated with side effects including atrial fibrillation, infections and bleeding, likely due to its off-target activity against other kinases. But acalabrutinib (ACP-196) “is a highly selective, potent BTK inhibitor developed to minimise off-target activity,” wrote Michael Wang, MD, of the department of lymphoma and myeloma at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.

After a median follow-up of 15.2 months, 81% of patients in the study achieved an investigator-assessed overall response based on Lugano classification, with 40% achieving a complete response. The results were similar according to an independent review committee evaluation of responses based on CT and PET scans, bone-marrow biopsy specimens, endoscopy results, and clinical data.

 

There was also a reduction in lymphadenopathy seen in 94% of patients. The patients who showed a complete response took a median of 3.4 months to get there, and the median time to best response was 1.9 months.

The researchers also looked at response rates across a number of prespecified subgroups. Patients with Ann Arbor stage IV disease, those with bone marrow involvement, and those with extranodal disease were less likely to achieve a complete response (29%, 14% and 28% respectively). Patients with lymph nodes 5 cm or larger in diameter showed a 78% response rate.

While the Kaplan-Meier estimated medians for duration of response, progression-free survival, and overall survival were not reached, 87% of patients achieved 12-month overall survival and 67% of patients achieved progression-free survival at 12 months.

Most of the adverse events were grade 1 or 2, and included headache, diarrhea, fatigue, and myalgia.

There were no grade 4 or 5 adverse events, but 10% of patients experienced neutropenia, 9% experienced anemia and 5% experienced pneumonia. There was also one case of grade 3 or worse hemorrhage, but no cases of atrial fibrillation. Lymphocytosis was seen in 31% of patients.

 

Nearly half of patients (44%) discontinued treatment, mostly because of progressive disease (31%) but 6% discontinued the treatment because of adverse events.

“Overall, treatment with acalabrutinib demonstrated a favourable benefit-risk profile and represents a promising treatment option for patients with relapsed or refractory mantle cell lymphoma,” the researchers wrote. “Data from the ongoing ACE-CL-006 trial directly comparing acalabrutinib with ibrutinib in previously treated patients with high-risk chronic lymphocytic leukaemia will further differentiate the safety profiles of the two treatments.”

The researchers noted a decrease in plasma levels of tumor necrosis factor alpha, the cytokine CXCL13, and other cytokines known to be involved in inflammation and cell trafficking.

“These findings add to the growing body of evidence indicating that BTK inhibition disrupts the tumour microenvironment, limiting the supply of cytokines and chemokines necessary for complex interactions with stromal and accessory cells important for tumour growth and survival.”

The study was sponsored by Acerta Pharma, a member of the AstraZeneca Group. Several study authors reported grants, personal fees and other support from the pharmaceutical industry, including Acerta Pharma, most outside the submitted work. Several authors were also employees of Acerta and some had acalabrutinib patents pending or issued.

hematologynews@frontlinemedcom.com

SOURCE: Wang M et al., Lancet. 2018;391:659-67.

A new Bruton tyrosine kinase inhibitor has shown a high response rate and favorable safety profile in the treatment of patients with mantle cell lymphoma.

Researchers reported the results of an open-label, phase 2 study of oral acalabrutinib (100 mg, twice daily) in 124 patients with relapsed or refractory mantle cell lymphoma in The Lancet. Acalabrutinib (Calquence) received accelerated approval from the Food and Drug Administration in October 2017 for treatment of adults with mantle cell lymphoma who have received at least one prior therapy.

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib (Imbruvica), which was approved in 2013 for the treatment of mantle cell lymphoma, has been associated with side effects including atrial fibrillation, infections and bleeding, likely due to its off-target activity against other kinases. But acalabrutinib (ACP-196) “is a highly selective, potent BTK inhibitor developed to minimise off-target activity,” wrote Michael Wang, MD, of the department of lymphoma and myeloma at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.

After a median follow-up of 15.2 months, 81% of patients in the study achieved an investigator-assessed overall response based on Lugano classification, with 40% achieving a complete response. The results were similar according to an independent review committee evaluation of responses based on CT and PET scans, bone-marrow biopsy specimens, endoscopy results, and clinical data.

 

There was also a reduction in lymphadenopathy seen in 94% of patients. The patients who showed a complete response took a median of 3.4 months to get there, and the median time to best response was 1.9 months.

The researchers also looked at response rates across a number of prespecified subgroups. Patients with Ann Arbor stage IV disease, those with bone marrow involvement, and those with extranodal disease were less likely to achieve a complete response (29%, 14% and 28% respectively). Patients with lymph nodes 5 cm or larger in diameter showed a 78% response rate.

While the Kaplan-Meier estimated medians for duration of response, progression-free survival, and overall survival were not reached, 87% of patients achieved 12-month overall survival and 67% of patients achieved progression-free survival at 12 months.

Most of the adverse events were grade 1 or 2, and included headache, diarrhea, fatigue, and myalgia.

There were no grade 4 or 5 adverse events, but 10% of patients experienced neutropenia, 9% experienced anemia and 5% experienced pneumonia. There was also one case of grade 3 or worse hemorrhage, but no cases of atrial fibrillation. Lymphocytosis was seen in 31% of patients.

 

Nearly half of patients (44%) discontinued treatment, mostly because of progressive disease (31%) but 6% discontinued the treatment because of adverse events.

“Overall, treatment with acalabrutinib demonstrated a favourable benefit-risk profile and represents a promising treatment option for patients with relapsed or refractory mantle cell lymphoma,” the researchers wrote. “Data from the ongoing ACE-CL-006 trial directly comparing acalabrutinib with ibrutinib in previously treated patients with high-risk chronic lymphocytic leukaemia will further differentiate the safety profiles of the two treatments.”

The researchers noted a decrease in plasma levels of tumor necrosis factor alpha, the cytokine CXCL13, and other cytokines known to be involved in inflammation and cell trafficking.

“These findings add to the growing body of evidence indicating that BTK inhibition disrupts the tumour microenvironment, limiting the supply of cytokines and chemokines necessary for complex interactions with stromal and accessory cells important for tumour growth and survival.”

The study was sponsored by Acerta Pharma, a member of the AstraZeneca Group. Several study authors reported grants, personal fees and other support from the pharmaceutical industry, including Acerta Pharma, most outside the submitted work. Several authors were also employees of Acerta and some had acalabrutinib patents pending or issued.

hematologynews@frontlinemedcom.com

SOURCE: Wang M et al., Lancet. 2018;391:659-67.

A new Bruton tyrosine kinase inhibitor has shown a high response rate and favorable safety profile in the treatment of patients with mantle cell lymphoma.

Researchers reported the results of an open-label, phase 2 study of oral acalabrutinib (100 mg, twice daily) in 124 patients with relapsed or refractory mantle cell lymphoma in The Lancet. Acalabrutinib (Calquence) received accelerated approval from the Food and Drug Administration in October 2017 for treatment of adults with mantle cell lymphoma who have received at least one prior therapy.

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib (Imbruvica), which was approved in 2013 for the treatment of mantle cell lymphoma, has been associated with side effects including atrial fibrillation, infections and bleeding, likely due to its off-target activity against other kinases. But acalabrutinib (ACP-196) “is a highly selective, potent BTK inhibitor developed to minimise off-target activity,” wrote Michael Wang, MD, of the department of lymphoma and myeloma at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.

After a median follow-up of 15.2 months, 81% of patients in the study achieved an investigator-assessed overall response based on Lugano classification, with 40% achieving a complete response. The results were similar according to an independent review committee evaluation of responses based on CT and PET scans, bone-marrow biopsy specimens, endoscopy results, and clinical data.

 

There was also a reduction in lymphadenopathy seen in 94% of patients. The patients who showed a complete response took a median of 3.4 months to get there, and the median time to best response was 1.9 months.

The researchers also looked at response rates across a number of prespecified subgroups. Patients with Ann Arbor stage IV disease, those with bone marrow involvement, and those with extranodal disease were less likely to achieve a complete response (29%, 14% and 28% respectively). Patients with lymph nodes 5 cm or larger in diameter showed a 78% response rate.

While the Kaplan-Meier estimated medians for duration of response, progression-free survival, and overall survival were not reached, 87% of patients achieved 12-month overall survival and 67% of patients achieved progression-free survival at 12 months.

Most of the adverse events were grade 1 or 2, and included headache, diarrhea, fatigue, and myalgia.

There were no grade 4 or 5 adverse events, but 10% of patients experienced neutropenia, 9% experienced anemia and 5% experienced pneumonia. There was also one case of grade 3 or worse hemorrhage, but no cases of atrial fibrillation. Lymphocytosis was seen in 31% of patients.

 

Nearly half of patients (44%) discontinued treatment, mostly because of progressive disease (31%) but 6% discontinued the treatment because of adverse events.

“Overall, treatment with acalabrutinib demonstrated a favourable benefit-risk profile and represents a promising treatment option for patients with relapsed or refractory mantle cell lymphoma,” the researchers wrote. “Data from the ongoing ACE-CL-006 trial directly comparing acalabrutinib with ibrutinib in previously treated patients with high-risk chronic lymphocytic leukaemia will further differentiate the safety profiles of the two treatments.”

The researchers noted a decrease in plasma levels of tumor necrosis factor alpha, the cytokine CXCL13, and other cytokines known to be involved in inflammation and cell trafficking.

“These findings add to the growing body of evidence indicating that BTK inhibition disrupts the tumour microenvironment, limiting the supply of cytokines and chemokines necessary for complex interactions with stromal and accessory cells important for tumour growth and survival.”

The study was sponsored by Acerta Pharma, a member of the AstraZeneca Group. Several study authors reported grants, personal fees and other support from the pharmaceutical industry, including Acerta Pharma, most outside the submitted work. Several authors were also employees of Acerta and some had acalabrutinib patents pending or issued.

hematologynews@frontlinemedcom.com

SOURCE: Wang M et al., Lancet. 2018;391:659-67.