CLL10 Phase III Trial Interim Analysis: FCR Has Greater Efficacy Than Bendamustine/Rituximab in the Treatment of Advanced CLL
• Interim analysis of CLL10 phase III trial: international, randomized study by the German CLL Study Group[1]
Summary of Key Conclusions
• In patients with untreated advanced chronic lymphocytic leukemia (CLL), without del(17)p and good physical fitness, interim analysis suggests frontline fludarabine/cyclophosphamide/rituximab (FCR) is more effective than bendamustine/rituximab (BR)
o CR rate
o Minimal residual disease negativity
o PFS
• IGHV status favored FCR arm
o Independent prognostic factor for PFS and event-free survival
• No differences observed for ORR and OS between arms
• Adverse events: FCR less tolerable than BR
o Higher incidence of neutropenia and infection with FCR
• Future studies should include anti-infective prophylaxis and re-evaluation of treatment during and after chemoradiotherapy
Background
• FCR current standard frontline treatment for advanced CLL[2]
• CLL8 clinical trial: FCR produced higher median PFS vs fludarabine/cyclophosphamide (57 vs 33 months, respectively)[3]
• Current study evaluated the safety and efficacy of standard frontline FCR treatment vs BR in physically fit patients with CLL and without del(17p)
Schematic of Study Design
Eligibility
• N = 561 patients with untreated, active CLL
o No del(17p)
o CIRS <= 6
o Creatinine clearance >= 70 mL/min
Baseline Characteristics
Description of Current Analysis
• Primary endpoint: noninferiority (efficacy, tolerability) of BR vs FCR
Main Findings
• Median PFS
o FCR: not reached
o BR: 44.9 months
o P = .04
• 2-year OS
o FCR: 94.2%
o BR: 95.8%
o P = .59
• ORR rates identical, but higher CR rates observed with FCR vs BR
• Median observation time: 27.9 months
• At final analysis, approximately 70% of patients across arms achieved MRD levels below 104
• Multivariate analysis identified multiple independent prognostic factors for PFS, with ß2-microglobulin and IGHV status most significant
• Significantly more adverse events associated with FCR vs BR
References
1. Eichhorst B, Fink A, Busch R, et al. Chemoimmunotherapy with fludarabine (F), cyclophosphamide (C), and rituximab (R) (FCR) versus bendamustine and rituximab (BR) in previously untreated and physically fit patients (pts) with advanced chronic lymphocytic leukemia (CLL): Results of a planned interim analysis of the CLL10 trial, an international, randomized study of The German CLL Study Group (GCLLSG). Program and abstracts of the 55th American Society of Hematology Annual Meeting and Exposition; December 7-10, 2013; New Orleans, Louisiana. Abstract 526.
2. Hallek M, Fischer K, Fingerie-Rowson G, et al. Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial. Lancet. 2010;376:1164-1174.
3. Fischer K, Bahlo J, Fink A, et al. Extended follow up of the CLL8 protocol, a randomized phase-III trial of the German CLL Study Group (GCLLSG) comparing fludarabine and cyclophosphamide (FC) to FC plus rituximab (FCR) for previously untreated patients with chronic lymphocytic leukemia (CLL): results on survival, progression-free survival, delayed neutropenias and secondary malignancies confirm superiority of the FCR regimen. Program and abstracts of the 54th American Society of Hematology Annual Meeting and Exposition; December 8-12, 2012; Atlanta, Georgia. Abstract 642.
