Ibrutinib discontinuation and associated factors in a real-world national sample of elderly Medicare beneficiaries with chronic lymphocytic leukemia

This study utilized Medicare claims from 2013 to 2019 to evaluate discontinuation rates of ibrutinib amongst 11,870 Medicare beneficiaries with CLL. With a median follow-up of 2 years, this study found that two-thirds of patients had discontinued ibrutinib within the first year of ibrutinib treatment. Factors associated with discontinuation of ibrutinib included advanced age, lack of part D low-income subsidy, prior CLL directed therapy, and presence of cardiovascular comorbidites. After a median of 1.2 years of follow-up after discontinuation, only 40% of patients restarted CLL-directed therapy, and one-quarter (25%) of patients restarted ibrutinib at some point during follow-up. Of note, this study captures a time frame that predates current data regarding efficacy of reduced doses of ibrutinib and the dose-related relationship seen with ibrutinib and several of its most common AEs. It does, however, reflect a need for better understanding of ibrutinib discontinuation rates outside the context of clinical trials.