Background: Most patients undergoing high-dose therapy and autologous transplant for multiple myeloma eventually develop a disease recurrence. However, to the authors' knowledge, the optimal salvage treatment for these patients is not well defined. Both autologous and allogeneic hematopoietic stem cell transplantations have been used for salvage therapy. The outcomes of salvage autologous or allogeneic transplants were analyzed retrospectively in patients relapsing after an autograft.
Methods: Fourteen patients (median age, 52 yrs) received a second autograft for salvage, whereas 26 patients (median age, 51 yrs) underwent a reduced-intensity allogeneic transplantation (related in 18 patients and unrelated in 8 patients). The median interval between the first and the second transplant was 25 months in the autologous group and 17 months in the allogeneic group. The two groups were evenly matched with regard to other disease characteristics.
Results: After a median follow-up of 18 months for the autologous group and 30 months for the allogeneic group, the median progression-free survival (PFS) and overall survival (OS) in the 2 groups were 6.8 months versus 7.3 months and 29 months versus 13 months, respectively. Acute and chronic graft versus host disease (15%) was the most common cause of non-recurrence mortality in the allogeneic group and infections (14%) in the autologous group. On univariate analysis, an interval of > 1 year between the first and the salvage transplant predicted a better OS in the allogeneic group.
Conclusions: Both autografting and allografting are feasible as salvage therapy for myeloma patients who develop disease recurrence after the first autograft, although disease progression remains the major cause of failure. Better approaches are needed for salvage therapy in patients developing disease recurrence after an autograft.