Impact of Ibrutinib Plus Venetoclax on Measurable Residual Disease Negativity Rates in CLL

By: Kayci Reyer
Posted: Friday, July 29, 2022

An interim analysis of the phase III FLAIR trial presented at the European Hematology Association (EHA) 2022 Congress (Abstract S145) reported that ibrutinib plus venetoclax may result in a strong measurable residual disease (MRD) negativity rate within the first 2 years of therapy among patients with treatment-naive chronic lymphocytic leukemia (CLL). Peter Hillmen, PhD, of St. James’s University Hospital, Leeds, United Kingdom, and colleagues found that the combination treatment yielded an MRD negativity rate in the peripheral blood of 71.9% and an MRD negativity rate in the bone marrow of 65.5%.

Patients were randomly assigned to receive either ibrutinib (n = 138) or ibrutinib plus venetoclax (n = 136); although the trial included 534 patients overall, the interim analysis assessed only the first 274 patients to reach the 2-year mark following randomization. A total of 72.3% of patients were male. The median patient age was 63 years, and 40.9% of patients had a Binet stage of C. Among the 93.4% of patients for whom IGHV mutation status was known, 45.3% had a mutation, 48.2% did not have a mutation, and 9.1% were categorized as subset 2. Variables were comparably distributed across treatment arms.

Within 24 months of combination treatment, 65.4% of patients given ibrutinib plus venetoclax achieved MRD negativity in the bone marrow and 71.3% achieved MRD negativity in the peripheral blood, versus zero patients who achieved MRD negativity in the monotherapy arm. MRD negativity rates were higher for patients without IGHV mutation. At 9 months, the overall response rate was 86.2% with monotherapy and 88.2% with combination therapy. Serious adverse event rates were similar with ibrutinib (38.2%) and ibrutinib plus venetoclax (41.5%) arms.

 

Disclosure: For full disclosures of the study authors, visit library.ehaweb.org

EHA 2022 Congress

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