Toxicity-reduced, myeloablative allograft followed by lenalidomide maintenance as salvage therapy for refractory/relapsed myeloma patients

Relapse after dose-reduced allograft in advanced myeloma patients remains high. To reduce the risk of relapse, we investigated a myeloablative toxicity-reduced allograft (aSCT) consisting of i.v. BU and CY followed by lenalidomide maintenance therapy in 33 patients with multiple myeloma (MM) who relapsed following an autograft after a median of 12 months. The cumulative incidence of non-relapse mortality at 1 year was 6% (95% confidence interval (CI): 0–14). After a median interval of 168 days following aSCT, 24 patients started with a median dose of 5 mg ( r , 5–15) lenalidomide without dexamethasone. During follow-up, 13 patients discontinued lenalidomide owing to progressive disease ( n =6), GvHD ( n =3), thrombocytopenia ( n =2), or fatigue ( n =2). Major toxicities of lenalidomide were GvHD II–III (28%), viral reactivation (16%), thrombocytopenia (III–IV°,16%), neutropenia (III/IV°, 8%), peripheral neuropathy (I/II°, 16%), or other infectious complication (8%). Cumulative incidence of relapse at 3 years was 42% (95% CI: 18–66). The 3-year estimated probability of PFS and OS was 52% (95% CI: 28–76) and 79% (95% CI: 63–95), respectively. Toxicity-reduced myeloablative allograft followed by lenalidomide maintenance is feasible and effective in relapsed patients with MM, but the induction of GvHD should be considered.