SECOND TRANSPLANTS FOR MULTIPLE MYELOMA RELAPSING AFTER A PRIOR AUTOTRANSPLANT – REDUCED INTENSITY ALLOGENEIC VERSUS AUTOLOGOUS TRANSPLANTATION

There is no standard therapy for multiple myeloma (MM) relapsing after an autotransplant. We compared the outcomes of a 2(nd) autotransplant (N=137) with those of an allotransplant (N=152) after non-myeloablative or reduced-intensity conditioning (NST/RIC) in 289 subjects reported to the CIBMTR from 1995–2008. NST/RIC recipients were younger (median age 53 vs. 56 years; p < 0.001) and had a shorter time to progression after their first autotransplant. Non-relapse mortality (NRM) at one-year post-transplant was higher in the NST/RIC cohort, 13% (95% CI, 8–19) vs. 2% (95% CI, 1–5, p = < 0.001). Three year progression-free survival (PFS) and overall survival (OS) for NST/RIC cohort were 6% (95% CI, 3–10%) and 20% (95% CI, 14–27%). Similar outcomes for the autotransplant cohort were 12% (95% CI, 7–19%, p = 0.038) and 46% (95% CI, 37–55%, p = 0.001). In multivariate analyses, risk of death was higher in NST/RIC recipients (HR 2.38 [95% CI, 1.79–3.16], p < 0.001), those with KPS < 90 (HR 1.96 [95% CI, 1.47–2.62], p < 0.001) and transplant before 2004 (HR 1.77 [95% CI, 1.34–2.35] p = < 0.001). In conclusion, NST/RIC was associated with higher TRM and lower survival than an autotransplant. Since disease status was not available for most allotransplant recipients, is not possible to determine which type of transplant is superior after autotransplant failure.