Prognostic factors and outcome in relapsed multiple myeloma after nonmyeloablative allo-SCT: a single center experience.

For relapsed multiple myeloma (MM) patients, allo-SCT is a possible treatment option, but recent data obtained using a nonmyeloablative (NMA) conditioning regimen are scarce. We retrospectively collected data from 38 relapsed MM patients who received a NMA allo-SCT from October 2001 to January 2008. In total, 18 patients (48%) were transplanted using a matched unrelated donor. The median follow-up is 2.3 years. In 16 patients (42%) the response improved and eight patients (21%) were rapidly progressive within 6 months after allo-SCT. In total, 15 patients (39%) were in CR after allo-SCT. The median PFS was 1.4 years (range, 0.1-4.9), and having a CR after allo-SCT or having chronic GVHD resulted in longer PFS. Median OS was 3.1 years (range, 0.2-7.2) and again having a CR after allo-SCT or chronic GVHD was associated with a better OS. Six patients (16%) have died from treatment-related diseases. These results indicate that NMA allo-SCT is a treatment option in relapsed MM patients and that results may be improved by strategies that enhance the CR rate after allo-SCT.