Lenalidomide as Salvage Therapy after Allogeneic Stem′Cell Transplantation in Multiple Myeloma

Lenalidomide is an immunmodulatory drug, orally administered once daily, which is effective in relapsed multiple myeloma (MM). Here, we evaluated the efficacy and toxicity of lenalidomide in 24 MM patients with relapsed disease after allogeneic stem cell transplantation (allo-SCT). Median age was 59 (range, 37–70) years. The series included 8 females and 16 males. Prior to allo-SCT, all patients were heavily pretreated with a median of 6 chemotherapy cycles including autologous and allo-SCT in all patients. Also, prior to lenalidomide, salvage treatment included donor lymphocyte infusions (DLI) in 18 pts,, thalidomide in 11 pts and bortezomib in 13 pts. Lenalidomide was given at 15mg (n=4) or 25 mg (n=20) orally once daily on day 1–21 every 28 days and in 20 patients in combination with dexamethason.. No prophylactic anticoagulation was used. The median number of completed cycles was 5 (range 2–17). Myelotoxicity according NCI criteria was the primarily and major encountered side effect (leukopenia: 4% grade 4, 21% grade 3, 17% grade 2, thrombopenia: 17% grade 3, 29% grade 2) and led to dose reduction in 54% of the patients. Infectious complications were observed in 50%. Non-hematological toxicity consisted of cramps (n=9), fatique (n=5) and constipation (n=2). Thrombembolic complications (cerebral infarction) were observed in one patient, who received concomitant corticosteroid treatment for acute graft-vs.-host disease (GvHD), but neurological symptoms resolved completely. GvHD of the skin under lenalidomide treatment was seen in 3 patients (one grade 2, and 2 grade 1), with one case occurring shortly after an additional DLI.. Objective remission was achieved in 66% of the patients (CR: 8%, VGPR: 8%, PR: 50%) and stable disease (SD) in 13% of the patients, while in 21% progressive disease was noted. Prior treatment with thalidomide or with bortezomib did not influenced the rate of CR/PR. Surprisingly, patients with del 13q14 achieved a higher CR/PR rate than those without del 13q14 (p=0.02). The median time to progression was 9.7 months (95% CI: 7.5–11.9) and the median overall survival was 19.9 months (95% CI: 17.3–22.5). Lenalidomide is effective in relapsed patients with MM after allo-SCT. Major toxicity is myelotoxicity, which required dose reduction in the majority of patients. The optimal dose of lenalidomide after allo-SCT has to be investigated.