Second Autologous Stem Cell Transplantation as Salvage Therapy for Multiple Myeloma: Impact on Progression-Free and Overall Survival

The role of a second autologous stem cell transplant (ASCT) as salvage therapy is unclear, particularly with the availability of novel agents to treat progressive multiple myeloma (MM). We retrospectively reviewed all MM patients who received a second ASCT as salvage therapy at our center from March 1992 to December 2009. Eighty-one MM patients received a second ASCT for relapsed MM. The median time to relapse after first transplant was 39 months (9.83-100). All patients received reinduction therapy before the second ASCT. The high-dose regimen given before the second ASCT consisted of melphalan (MEL) alone in the majority. Complete response, very good partial response, and partial response were seen in 7.7%, 39.7%, and 50%, respectively, at day 100 post-ASCT; the median time to relapse after the second ASCT was 19 months. Early deaths occurred in 2.6%. Median progression-free survival (PFS) based on the time to myeloma relapse after first ASCT was 9.83 months (relapse ≤24 months) and 17.3 months (relapse ≥24 months) (P < .05). Median overall survival (OS) was 28.47 months (relapse ≤24 months) and 71.3 months (relapse >24 months) (P = .006). Second ASCT is a feasible and safe option for salvage therapy in MM. The best outcome was observed in patients whose time to progression was >24 months after first ASCT, as these patients had a subsequent PFS lasting over 1 year and an OS of almost 6 years.