Long-term results of first salvage treatment in CLL patients treated initially with FCR (fludarabine, cyclophosphamide, rituximab).

Although fludarabine, cyclophosphamide, and rituximab (FCR) together are established as a standard first-line treatment of younger patients with chronic lymphocytic leukemia (CLL), there is little information to guide the management of patients with CLL refractory to, or who have relapsed after, receiving frontline FCR treatment. To define optimal salvage strategy and identify patients unsuitable for retreatment with FCR, we examined the survival and treatment outcome of 300 patients enrolled in a phase 2 study of FCR. After a median 142 months of follow-up, 156 patients developed progressive CLL, with a median survival of 51 months after disease progression. The duration of first remission (REM1) was a key determinant of survival after disease progression and first salvage. Patients with a short REM1 (<3 years) had a short survival period, irrespective of salvage therapy received; these patients have high unmet medical needs and are good candidates for investigation of novel therapies. In patients with a long REM1 (≥3 years), salvage treatment with either repeat FCR or lenalidomide-based therapy results in subsequent median survival exceeding 5 years; for these patients, FCR rechallenge represents a reasonable standard of care.