In this study of 71 patients with multiple myeloma undergoing allogeneic hematopoietic cell transplantation (HCT), 5-year overall survival (OS) was 60%, with better outcomes in patients ≤55 years and in those transplanted with chemosensitive disease.
Forty-three patients (61%) were transplanted after the first line of therapy and 58 patients (82%) had chemosensitive disease at the time of transplant.
Cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) at day 100 was 13% and chronic GVHD at 5 years was 35%. Non-relapse mortality and relapse/progression incidence at 5 years were 12% and 65%, respectively. At a median follow-up of 100 months, 5-year progression-free survival (PFS) was 39%.
A multivariate analysis revealed that age >55 years was significantly associated with both a reduced PFS (RR 2.11, 95% CI 1.15-3.87) and OS (RR 5.53, 95% CI 2.22-13.76), and that chemorefractory disease was significantly associated with both reduced PFS (RR 3.09, 95% CI 1.37-7.00) and OS (RR 3.19, 95% CI 1.23-8.22).
Patients relapsing post-transplant received bortezomib, lenalidomide, pomalidomide or donor lymphocytes infusion as part of salvage therapy. Median PFS from time of salvage treatment was 7 months (range 0-113 months) for bortezomib-based therapy, 14 months (range 0-79 months) for lenalidomide and 10 months (range 1-28) for pomalidomide.
The researchers concluded that “it is reasonable to consider allo-HCT for young, carefully selected, high-risk patients at first relapse, in line with established guidelines.”