Bendamustine and Rituximab for the Treatment of Chronic Lymphocytic Leukemia: The Moffitt Cancer Center Experience

Although bendamustine is approved for the treatment of chronic lymphocytic leukemia (CLL), the combination of bendamustine and rituximab (BR) is currently under active investigation in the relapsed/refractory setting as well as for front-line use. Emerging data now suggests BR is acceptable for first-line use and indeed is listed in the NCCN Compendia as a first-line option. Herein, we report the results of a single-center retrospective review of BR use in first-, second- and third-line and beyond and its effects on response rate.

We retrospectively reviewed 21 consecutive patients with CLL that received BR at the Moffitt Cancer Center (MCC) between July 2008 and November 2010. Bendamustine was dosed at 70 mg/m² IV on Days 1 and 2 every 3–4 weeks; rituximab was dosed at 375 mg/m² IV once with each cycle along with anti-microbial prophylaxis. Data collected included, but was not limited to age, gender, cytogenetic profile, number of previous therapies, Rai stage at time of treatment and response (based on 1996 NCI-WG definition). The primary objective was to assess response rates. The major secondary objective was to assess the effect of cytogenetics on response rates. All analyses were performed using descriptive statistics.

Twenty-one patients received treatment with BR; 7 patients received BR as first-line therapy, 7 received BR as second line therapy and the remaining 7 received BR as third-line therapy or beyond. The median age at time of treatment was 66; 12 of 21 patients were male (57%); All Rai Stages were represented, Stage 0 (n=1), Stage 1 (n=4), Stage 2 (n= 3), Stage 3 (n=5), Stage 4 (n=6). 38% of patients were positive for Del11q, 33% for Del13q, 9.5% for Del17p, and 9.5% for mutated IgVH. In previously untreated patients, 6/7 had a documented complete remission (CR) (71.4%) or partial (PR) (14.3%) response; one patient progressed (PD) on therapy. In second-line therapy, all patients had a documented CR (28.6%) or PR (71.4%). In patients treated with BR as 3^rd or 4^th line therapy, 3 patients had a CR, 2 patients had stable disease (SD), and 2 had PD. Of the 8 patients with Del11q, 37.5% achieved a CR, 4 had PR and 1 had PD. Of the 7 patients with Del13q, 4 achieved CR and 3 had a PR. Both patients with Del17p had PD. Of the 2 patients with mutated IgVH, one patient achieved a PR while the other had PD.

Based on these results, the combination of bendamustine and rituximab in patients with CLL is efficacious and well tolerated in patients with both newly diagnosed and relapsed/refractory disease.

Off Label Use: Bendamustine and rituximab for CLL. Ho:Genentech: Honoraria; Cephalon: Consultancy. Cultrera:Genentech: Speakers Bureau. Sotomayor:Genentech: Membership on an entity’s Board of Directors or advisory committees. Pinilla-Ibarz:Genentech: Speakers Bureau; Cephalon: Speakers Bureau.