Bendamustine Study Demonstrates Significant Improvement in Overall Response and Progression-Free Survival in CLL Patients

Data from a pivotal phase III study demonstrate that bendamustine (Treanda) improved clinical outcomes when compared to chlorambucil (Leukeran) in patients with chronic lymphocytic leukemia (CLL). Results of this study were the basis of the March 2008 US Food and Drug Administration (FDA) approval of bendamustine for CLL, the first agent approved by the FDA for this disease since 2001. The study results were published August 24, 2009, by the Journal of Clinical Oncology online and will also appear in the print edition later this year.

This phase III, randomized, international, multicenter, open-label study evaluated the efficacy and safety of bendamustine compared to chlorambucil in previously untreated patients with advanced (Binet stage B–C) CLL. Patients received bendamustine (100 mg/m² on days 1 and 2; n = 162) or chlorambucil (0.8 mg/kg on days 1 and 15, n = 157) for up to six treatment cycles. In this study, bendamustine demonstrated significantly better outcomes for both primary endpoints compared to chlorambucil: overall response rate and progression-free survival (PFS).The overall response rate was significantly higher in patients receiving bendamustine than chlorambucil (68% vs 31%; P < .0001). Patients in the bendamustine treatment arm also had a higher complete response rate than those treated with chlorambucil (31% vs 2%).

Limited Treatment Options
“CLL is the most common form of adult leukemia in the Western world. Because it is incurable, the goal of treatment is to stabilize the cancer over the long-term by extending periods of remission,” said Prof. Wolfgang Knauf, Onkologische Gemeinschaftspraxis, Frankfurt, Germany and lead investigator of this study. “Treatment options are limited for those with advanced CLL, but this study shows that bendamustine demonstrates significantly better efficacy compared to chlorambucil with a tolerable safety profile.”

The study also showed that patients treated with bendamustine had significantly longer PFS compared to chlorambucil (median PFS 21.6 vs 8.3 months; P < .0001). Bendamustine was also associated with an improvement in duration of response compared to chlorambucil (21.8 vs 8 months). In the study, bendamustine demonstrated a tolerable safety profile; the most common adverse events included myelosuppression, fever, nausea, vomiting, and diarrhea.