ASH 2020: Phase II CAPTIVATE Study Update on Ibrutinib Plus Venetoclax in CLL
Posted: Monday, December 7, 2020
The results from the minimal residual disease (MRD) cohort of the CAPTIVATE study suggest that treatment-free remission may be a feasible option for patients with chronic lymphocytic leukemia (CLL) who achieved confirmed undetectable MRD after first-line treatment with a combination of ibrutinib and venetoclax. In fact, the 30-month progression-free survival rate from the initial treatment was more than 95% across all arms. William G. Wierda, MD, PhD, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues presented the latest study data at the 2020 American Society of Hematology (ASH) Annual Meeting and Exposition (Abstract 123).
This phase II study enrolled previously untreated patients up to age 70 with CLL or small lymphocytic leukemia to receive three cycles of ibrutinib lead-in and 12 cycles of ibrutinib plus venetoclax. In the MRD cohort, 86 patients who had achieved confirmed undetectable MRD after initial treatment—defined as undetectable MRD serially over at least three cycles in both peripheral blood and blood marrow—were randomly assigned to receive either placebo (n = 43) or ibrutinib (n = 43). In this arm, the 1-year disease-free survival rate was not significantly different for patients randomly assigned to placebo versus ibrutinib (P = .1475), “supporting a fixed-duration treatment that offers treatment-free remission.”
Patients who did not achieve confirmed undetectable MRD were randomly assigned to receive ibrutinib (n = 31) or ibrutinib plus venetoclax (n = 32). The undetectable MRD rates at randomization in the arm that did not achieve confirmed undetectable MRD were 48% in peripheral blood and 32% in bone marrow. This increased to 57% and 54%, respectively, after continuing treatment.
As for toxicity, the safety profile of ibrutinib plus venetoclax was consistent with known adverse events. Adverse events were primarily grade 1 and 2 during this portion of the study and mostly occurred in early cycles.
Disclosure: For full disclosures of study authors, visit ash.confex.com.