Bendamustine + Rituximab Shows Efficacy in Previously Untreated CLL
The German Chronic Lymphocytic Leukemia Study Group multicenter phase 2 study treated 117 treatment-naïve patients ranging in age from 34 to 78 years with bendamustine 90mg/m2 on days 1 and 2 combined with 375mg/m2 rituximab on day 0 of the first course and 500mg/m2 on day 1 during subsequent courses for up to 6 courses. Of the patients, 46.2% had Binet stage C and 25.6% were 70 years of age or older.
Complete response rate was 23.1% and partial response, 64.9%, for an overall response rate of 88.0% (95% CI, 80.7% –100.0%). “Ninety percent of patients with del(121q), 94.7% with trisomy 12, 37.5% with del(17p), and 89.4% with unmutated IGHV status responded to treatment,” the investigators noted. At a median follow-up of 27.0 months, median event-free survival was 33.9 months; 90.5% of patients were alive.
Grade 3 or 4 severe infections occurred in 7.7% of patients; grade 3 or 4 adverse events included neutropenia (19.7%), thrombocytopenia (22.2%), and anemia (19.7%).
They concluded that in this representative population of patients with CLL, “except for patients with del(17p) who did not respond to the treatment regimen as the other genetic subgroups, the combination of bendamustine and rituximab offers an effective and safe treatment for patients with treatment-naïve CLL.”
Based on these results, the group has initiated a phase 3 trial comparing the bendamustine/rituximab regimen with standard first-line therapy, fludarabine, cyclophosphamide, and rituximab (FCR), “to study the question of whether therapy with bendamustine and rituximab is not inferior to therapy with FCR.”