The Role of Allogeneic Transplantation for Multiple Myeloma in the Era of Novel Agents: A Study from the Japanese Society of Myeloma.

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered a potentially curative therapy for patients with multiple myeloma, the role of allo-HSCT remains unclear in the novel agent era. We conducted a retrospective study of 65 patients with multiple myeloma who underwent allo-HSCT at 19 institutions from 2009 to 2016. Patients received a median of 3 (range, 1 to 7) lines of prior therapy, including at least 1 novel agent, except for autologous HSCT. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 18.8% (95% confidence interval [CI], 9.6% to 30.3%) and 47.2% (95% CI, 33.9% to 59.4%), respectively. In a multivariate analysis, an age ≥50 years and less than a very good partial response (VGPR) before allo-HSCT were independent significant adverse factors for PFS (hazard ratio [HR], 2.30, P = .0063; HR, 2.86; P = .0059) and OS (HR, 2.37, P = .013; and HR, 2.74; P = .040). In contrast, the 3-year PFS and OS rates in patients <50 years of age who achieved a VGPR or better before allo-HSCT were 64.3% (95% CI, 29.8% to 85.1%) and 80.2% (95% CI, 40.3% to 94.8%), respectively. The overall response rate was 86.4% (95% CI, 75.0% to 94.0%). The proportion of VGPR or better increased from 29% before allo-HSCT to 71% after allo-HSCT. The nonrelapse mortality at 3 years was 23.4% (95% CI, 13.8% to 34.4%). Only an age ≥50 years was associated with higher nonrelapse mortality (HR, 4.71; P = .015). We showed that allo-HSCT is feasible for heavily pretreated patients with multiple myeloma, even in the novel agent era. Allo-HSCT in particular is a promising therapy for young and chemosensitive patients.