Second stem cell transplantation for treatment of relapsed/refractory multiple myeloma after first autologous stem cell transplant: A 15-year retrospective institutional analysis

Abstract Background: Multiple myeloma remains an incurable disease, with the majority of patients relapsing after autologous stem cell transplant (ASCT). After relapse, second transplant remains one of the therapeutic options, along with novel agents. Methods: We reviewed the data of our patients who underwent ASCT for myeloma ( N = 202) over the last two decades (2004–2019). Of these, 12 patients underwent a second transplant. Results: Out of 12 patients, nine underwent second autologous stem cell transplant, whereas three received an allogeneic stem cell transplantation (Allo-SCT). Median progression-free survival (PFS) after the first ASCT was 32 months (5–84 months). Median interval between both the transplants was 35 months (4–159 months). Median age of our cohort which underwent second transplant was 56 years. Overall response rate (ORR) post-second transplant on day +100 was 83.3%, without any transplant-related mortality (TRM). With the use of preemptive plerixafor, none of our patients required a second day for stem cell harvest. Median CD34 dose of stem cells infused was 4.11 × 10 6 /kg. Similar to the first ASCT, the median time to neutrophil and platelet engraftment was 11 and 12 days, respectively. At a median follow-up of 41 months, estimated 3-year PFS and overall survival (OS) was 37% ± 15% and 63% ± 15%, respectively. Conclusion: Among all relapsed myeloma patients who were transplant eligible, 11% underwent a second transplant. Second transplant is well tolerated with similar time to engraftment after first ASCT. Hence, we believe that second transplant is a feasible, cost-effective option in a resource-limited setting, which should be more widely utilized.