Polish experience of lenalidomide in the treatment of lower risk myelodysplastic syndrome with isolated del(5q).

ABSTRACT

BACKGROUND: Lenalidomide has been approved for the treatment of lower-risk myelodysplastic syndrome (MDS) with 5q deletion (del(5q)). We present for the first time a retrospective analysis of low-risk MDS with isolated del5q treated with lenalidomide, outside the clinical trials. METHODS: 36 red blood cell (RBC) transfusion-dependent patients have been included in the study. Patients received lenalidomide 10 mg/day on days 1-21 of 28-day cycles. RESULTS: 91.7 % of patients responded to lenalidomide treatment 72.2 % achieved erythroid response, 19.4 % achieved minor erythroid response and 8.4 % of patients did not respond to treatment. Response depended on number of previous treatment lines (p = 0.0101), International Prognostic System Score (IPSS; p = 0.0067) and RBC transfusion frequency (p = 0.0139). Median duration of response was 16 months (range 6-60 months). Treatment was well tolerated. We observed hematological toxicity (grade 3 and 4) neutropenia in 16 (44.4 %) patients and thrombocytopenia in 9 (25 %) patients. Two patients (5.5 %) progressed to high-risk MDS and two subsequent progressed to acute myeloid leukemia. A Kaplan-Meier estimate for overall survival at 5 years in the study group was 79.0 ± 8.8 %. CONCLUSIONS: Lenalidomide in this group of patients was beneficial for the treatment of RBC transfusion-dependency with well-known safety profile.