Low-dose fludarabine and cyclophosphamide combined with standard dose rituximab (LD-FCR) is an effective and safe regimen for elderly untreated patients with chronic lymphocytic leukemia: The Israeli CLL study group experience

Chronic lymphocytic leukemia (CLL) is a disease of elderly patients. The fludarabine, cyclophosphamide, and rituximab (FCR) regimen is considered the treatment of choice for young fit patients with CLL; however, this combination is toxic for older patients. At the time this study was first planned and initiated, there was no standard chemo-immunotherapy regimen regarded as standard therapy for the less fit elderly patient with CLL. Here, we conducted a single-arm, phase II trial to examine the efficacy and safety of lower-dose fludarabine and cyclophosphamide combined with a standard dose of rituximab (LD-FCR) in elderly patients with previously untreated CLL. Forty patients received LD-FCR and were included in the efficacy analysis. Two patients treated with FC alone were only included in the safety analysis. The median age was 72.7 years (range, 65.0 to 85.0). The overall response and complete response rates were 67.5% and 42.5%, respectively. Median progression-free survival (PFS) was 35.5 months (95% CI, 29.27-41.67). Two patients (4.8%) died during the study period. Hematological toxicities and infections were the most common complications encountered; grade 3 to 4 treatment-related neutropenia occurred in 20 (47.6%) patients. During the entire study follow-up, 26 patients (61.9%) had all grades of infection including six (14.3%) with neutropenic fever and eight (19%) with grade 3 to 4 non-neutropenic infections. In conclusion, LD-FCR is an effective and relatively safe regimen for previously untreated patients with CLL. It has the advantage of being both “time and cost limited” and, even in the era of novel agents, can still be considered when planning treatment for elderly patients without high-risk biomarkers. However, recent results in fit elderly patients using the combination of bendamustine and rituximab which have achieved longer PFS with good safety profile must be taken into consideration in this regard.