Ibrutinib Decreases Relapse in Patients With Chronic Lymphocytic Leukemia

A study presented at ASH Annual Meeting 2018 would suggest that ibrutinib is a strong option for patients aged 65 and older in the prevention of relapse in patients with chronic lymphocytic leukemia (CLL).

Presenter, Jennifer A. Woyach, MD, Ohio State Cancer Center began, “The most effective initial therapy for older adults with CLL has not yet been established due to the lack of comparison of chemoimmunotherapy (CIT) and targeted therapy with the Bruton tyrosine kinase (BTK) inhibitor ibrutinib. CIT has been the gold standard since studies showing that addition of CD20 antibody to chemotherapy prolongs survival.”

“Bendamustine plus rituximab (BR) is one standard, more aggressive CIT regimen for patients age 65 or older,” the study continued. “While ibrutinib has been FDA approved for untreated CLL since 2016, it has only been compared to chlorambucil, which is relatively ineffective, and never before to aggressive CIT.” 

“Alliance A041202 is a multicenter NCI National Clinical Trials Network phase 3 study comparing BR (Arm 1) with ibrutinib (Arm 2) and the combination of ibrutinib plus rituximab (Arm 3) to determine whether ibrutinib-containing regimens are superior to CIT in terms of progerssion-free survival. Additionally, this study sought to determine if adding rituximab to ibrutinib would prolong PFS over ibrutinib alone. At time of progression, patients on Arm 1 could cross over to Arm 2.

According to the study’s results, there was about a 60% reduction in relapse or death and adding rituximab to the ibrutinib was not any more successful than using ibrutinib alone. There was no difference in overall survival for these patients but the statistics suggest that for patients older than 65 years, ibrutinib is more effective at preventing relapse and death. 

“This international phase 3 trial demonstrates that ibrutinib produces superior PFS to standard CIT in older patients with CLL and justifies it as a standard of care treatment for patients age 65 and older. The addition of rituximab does not prolong PFS with ibrutinib. While ibrutinib represents a major therapeutic advance, toxicities and also cost justify future efforts to reduce the need for long-term continuous treatment.” .

—Edan Stanley