Contribution of post-transplantation therapy to sustained MRD negativity in multiple myeloma: a retrospective analysis.

Post-transplantation therapy is commonly performed in patients with myeloma and can prolong progression-free survival (PFS). However, whether post-transplantation therapy contributes to achieving and continuing MRD-negativity remains controversial. This retrospective analysis aimed to evaluate the clinical impact of post-transplantation therapy, including tandem autologous stem cell transplantation (ASCT), in myeloma patients. The subjects were 79 patients (median age: 62 years) who received induction therapy, including bortezomib and/or lenalidomide, of whom 58 underwent post-transplantation therapy. At the median follow-up time of 50 months, the 4-year PFS rate was significantly higher in patients who underwent post-transplantation therapy than those who did not (60.6% vs. 28.6%, P = 0.012). Multivariate analysis revealed post-transplantation therapy to be a significant prognostic factor for long PFS. Tandem ASCT followed by consolidation and/or maintenance therapies improved PFS and OS. The minimal residual disease (MRD)-negative rate was significantly higher in patients who underwent post-transplantation therapy than those who did not (50.9% vs. 16.7%, P = 0.006). Post-transplantation therapy contributed to sustained MRD-negativity, which predicted long PFS and overall survival. Patients frequently discontinued post-transplantation therapy due to adverse events within 4 months. In conclusion, post-transplantation therapy improved PFS and contributed to sustained MRD-negativity in myeloma patients.