Seymour JF, et al. - This study entailed the analysis of the efficacy of venetoclax in combination with rituximab in subjects with relapsed or refractory chronic lymphocytic leukemia. Yielded data exhibited that significantly higher rates of progression-free survival were obtained among patients with relapsed or refractory chronic lymphocytic leukemia, venetoclax plus rituximab vs bendamustine plus rituximab.

Methods

• The scheme of this research was a randomized, open-label, phase 3 trial.
• A total of 389 patients were allocated to receive venetoclax for up to 2 years (from day 1 of cycle 1) plus rituximab for the first 6 months (venetoclax-rituximab group) or bendamustine plus rituximab for 6 months (bendamustine-rituximab group).
• Exclusion criteria included crossover to venetoclax plus rituximab for patients in the bendamustine-rituximab group in whom progression occurred.
• Investigator-assessed progression-free survival served as the primary endpoint.

Results

• Prominently higher rate of investigator-assessed progression-free survival was discovered in the venetoclax-rituximab group (32 events of progression or death in 194 patients) than in the bendamustine-rituximab group (114 events in 195 patients) after a median follow-up period of 23.8 months.
• It was determined that the 2-year rates of progression-free survival were 84.9% and 36.3%, respectively (hazard ratio for progression or death, 0.17; 95% confidence interval [CI], 0.11 to 0.25; P < 0.001 by the stratified log-rank test).
• Across all clinical and biologic subgroups, the benefit was maintained, with the inclusion of the subgroup of patients with chromosome 17p deletion.
• Findings revealed that the 2-year rate of progression-free survival among patients with chromosome 17p deletion was 81.5% in the venetoclax-rituximab group compared to 27.8% in the bendamustine-rituximab group (hazard ratio, 0.13; 95% CI, 0.05 to 0.29).
• Furthermore, the 2-year rate among those without chromosome 17p deletion was found to be 85.9% vs 41.0% (hazard ratio, 0.19; 95% CI, 0.12 to 0.32).
• An independent review committee assessment of progression-free survival and other secondary efficacy end points affirmed the benefit of venetoclax plus rituximab over bendamustine plus rituximab.
• Higher rate of grade 3 or 4 neutropenia was demonstrated in the venetoclax-rituximab group compared to the bendamustine-rituximab group.
• Nevertheless, the rates of grade 3 or 4 febrile neutropenia and infections or infestations appeared to be lower with venetoclax than with bendamustine.
• In the venetoclax-rituximab group, the rate of grade 3 or 4 tumor lysis syndrome was disclosed to be 3.1% (6 of 194 patients).