Rituximab in Combination with Bendamustine or Chlorambucil for Treating Patients with Chronic Lymphocytic Leukemia: Interim Results of a Phase IIIb Study (MaBLe)

• Published in: Blood 2012-11, Vol.120 (21), p.2744-2744
• Main Authors: Leblond, Veronique, Laribi, Kamel, Ilhan, Osman, Aktan, Melih, Unal, Ali, Rassam, Saad M B, Schuh, Anna, Widenius, Tom, Johansson, Peter, Raposo, Joao, Meddeb, Balkis, Moreno, Carol, Oertel, Stephan H.K., Michallet, Anne-Sophie
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V120.21.2744.2744

Abstract 2744 The current standard of care for fit patients (pts) with chronic lymphocytic leukemia (CLL) is rituximab (R) in combination with fludarabine and cyclophosphamide; however, many pts with CLL are elderly and have comorbidities that render them ineligible for fludarabine treatment. Two common treatment options for fludarabine-ineligible pts are bendamustine (B) or chlorambucil (Clb). A further promising treatment option, following the success of the combination of R with fludarabine and cyclophosphamide, might be to combine B or Clb with R. The following study aims to assess the responses of pts to a combination of R and either B or Clb in first-line (1L) or second-line (2L) pts with CLL, with the primary objective being to compare the confirmed complete response (CR) rate (assessed according to Hallek et al. Blood 2008) after 6 cycles of treatment between the two treatment arms for the pooled 1L and 2L pts. Pts (aged ≥ 18 years) who were ineligible for fludarabine treatment, as a result of age or a greater number of comorbidities, were randomized to either the R-B or R-Clb arm. Pts were 1L or 2L, where relapse had occurred no earlier than 12 months since their last dose of 1L treatment. Pts in the R-B arm were treated with six 28-day cycles of B (1L: 90 mg/m2 Days 1 and 2; 2L: 70 mg/m2 Days 1 and 2) with R administered on Day 1 of cycle 1 (375 mg/m2) and cycles 2–6 (500 mg/m2). Pts in the R-Clb arm received the same dose of R but in place of B they received Clb (10 mg/m2Days 1–7, cycles 1–6), and those pts in the R-Clb arm that had not achieved a CR after 6 cycles continued to receive Clb monotherapy for up to 6 further cycles. Tumor assessments were made after cycles 3, 6 and 12 and then 3-monthly for at least a year. Enrollment and randomization are ongoing and, at present, a total of 339 pts have been randomized between the two treatment arms, 126 of whom are included in this interim analysis with the remaining pts continuing on the study. Of these 126 pts, 58 were randomized into the R-B arm and 68 the R-Clb arm. Patient characteristics between the two treatment arms were well balanced (Table). The median age of pts was 74 years (75 years for the R-B arm and 73 years for the R-Clb arm) and the majority of pts were taking concomitant medication (57/58 pts [98%] in the R-B arm; 64/68 pts [94%] in the R-Clb arm). Compared with previous clinical trials in CLL where pts are usually younger and fitter, this patient population is closer in age and