A longer follow-up of a phase 3 study confirmed that fixed-duration venetoclax-rituximab therapy delivers durable clinical responses and a survival advantage compared with bendamustine-rituximab therapy in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Researchers report in the Journal of Clinical Oncology that venetoclax, which is a highly selective inhibitor of B-cell lymphoma, showed continued benefit compared with bendamustine, and predicted longer progression-free survival (PFS).1
Arnon Kater, MD, PhD, with Amsterdam Universitair Medische Centra, University of Amsterdam, the Netherlands, and colleagues examined treatment effect and minimal residual disease (MRD) kinetics now that all the patients in the phase 3 arm of the MURANO trial have stopped receiving this treatment.
In the trial, patients were randomly assigned to receive either 2 years of venetoclax plus rituximab during the first 6 cycles or 6 cycles of bendamustine-rituximab. The researchers found that 90% of patients completed the venetoclax-rituximab phase (174 of 194) and 67% of patients completed 2 years of venetoclax (130 of 194). The PFS rates at a median follow-up of 36 months showed venetoclax-rituximab was superior to bendamustine-rituximab (hazard ratio [HR], 0.16; median not reached vs 17.0 months, respectively). The study showed that the 3-year PFS estimates were 71.4% for patients given venetoclax-rituximab and 15.2% for those in the bendamustine-rituximab arm.
The researchers also found that patients who received venetoclax-rituximab achieved a higher rate of peripheral blood undetectable MRD (uMRD) at the end of combination therapy (EOCT) than did patients who were administered bendamustine-rituximab (62% vs 13%, respectively), with superiority sustained through month 24. The study also revealed that uMRD status at EOCT was able to predict longer PFS.
- Kater AP, Seymour JF, Hillmen P, et al. Fixed duration of venetoclax-rituximab in relapsed/refractory chronic lymphocytic leukemia eradicates minimal residual disease and prolongs survival: post-treatment follow-up of the MURANO phase 3 study [published online December 3, 2018]. J Clin Oncol. doi: 10.1200/JCO.18.01580