Lenalidomide and Prednisone in Low and Intermediate-1 IPSS Risk, Non-Del(5q) Patients With Myelodysplastic Syndromes: Phase 2 Clinical Trial.

Purpose: To test the hypothesis that combination treatment with lenalidomide and prednisone will yield a higher erythroid response rate in patients with non-del(5q) lower-risk myelodysplastic syndromes compared to the historical clinical trial data with lenalidomide monotherapy, which reported a 26% transfusion independence rate.

Patients And Methods: The study enrolled 25 patients with lower-risk myelodysplastic syndromes by the International Prognostic Scoring System who were transfusion dependent or who had symptomatic anemia and prior erythroid stimulating agent failure or low chance of response. The planned dose of lenalidomide was 10 mg per day. Prednisone dose was 30 mg by mouth, daily cycle 1 tapered by 10 mg after each cycle to 5 mg by mouth every other day for those with response beyond cycle 6. The primary objective was best response (hematologic improvement-erythroid, HI-E) by International Working Group 2006 criteria within 24 weeks.

Results: The HI-E rate was 20% (5/25) and was 22% (5/23) for patients with evaluable data. All those with response became red blood cell-transfusion independent (5/23). The median time to response was 57 days. The median duration of response was 80 days (95% confidence interval, 69-91). Three of 5 of those with response did not have prior hypomethylating agent, while 14 of 20 those without response received a hypomethylating agent.

Conclusion: The combination was relatively well tolerated, with no additional observed toxicity to single-agent lenalidomide.