Cyclophosphamide’s addition in relapsed/refractory multiple myeloma patients with biochemical progression during lenalidomide‐dexamethasone treatment

Objective The aim of this study was to evaluate the addition of cyclophosphamide in relapsed‐refractory multiple myeloma patients ( RRMM ) who experienced biochemical relapse or progression without CRAB , during treatment with lenalidomide and dexamethasone (Rd), to slow down the progression in active relapse. Methods This analysis included 31 patients with RRMM treated with Rd who received cyclophosphamide ( CR d) at biochemical relapse. The CR d regimen was continued until disease progression. Results The median number of CR d cycles administered was 8 (range: 1‐35). A response was observed in 9 (29%) patients. After a median observation time of 11 months, the median overall survival ( OS ) from the beginning of CR d was 17.7 months. The median progression‐free survival ( PFS ) from the beginning of CR d was 13.1 months. Conclusion The addition of cyclophosphamide delays the progression in patients who present a biochemical relapse during Rd treatment. The response rate and the duration of PFS obtained with minimal toxicities and low costs induced us to setting up a randomized clinical trial.