Long-Term Outcomes of Autologous Transplantation in Multiple Myeloma: Significant Survival Benefit of Novel Drugs in Post-Transplantation Relapse

Background: Autologous stem cell transplantation (autoSCT) has an important role in the treatment of patients with symptomatic multiple myeloma (MM). Treatment options for myeloma have expanded in the past decade, and it seems that patients who are treated with novel drugs such as thalidomide and bortezomib for relapse after autoSCT have longer overall survival (OS). Patients and Methods: Herein, we describe the long-term outcome of a cohort of 185 patients with newly diagnosed MM treated with autoSCT. We have analyzed factors that might predict for long-term survival. Results: Following autoSCT, the overall response rate was 94% (173 of 185 patients); 29% (53 of 185 patients) were in complete remission (CR). Median time to progression (TTP) and OS from start of therapy were 39.8 months and 77.9 months, respectively. The median follow-up was 103.8 months (range, 60.8-144.8 months); 23% of the patients are alive and disease free, 21% of the patients are alive with relapse, and 56% of the patients have died. On multivariate analysis, factors associated with significantly better OS were International Staging System (ISS) disease stage < III (hazard ratio [HR], 2.6; P < .001), achievement of CR after autoSCT (HR, 2.8; P < .001) and use of thalidomide (HR, 4.3; P < .001) and/or bortezomib (HR, 7.3; P < .001) in posttransplantation relapse treatment. The patients' age, renal impairment, disease status before autoSCT and maintenance therapy with interferon-alpha (IFN-alpha) or IFN-alpha and dexamethasone did not significantly affect TTP and OS after transplantation. Conclusion: According to our results, the achievement of CR after transplantation, ISS stage other than III, and administration of thalidomide or bortezomib in posttransplantation relapse were significant parameters favoring long-term posttransplantation survival.