Despite novel agents, multiple myeloma (MM) remains incurable. The majority of patients with MM will relapse at some stage after induction therapy and high dose chemotherapy with autologous stem cell transplant (ASCT). Published studies have recommended salvage ASCT as an effective option in patients with relapsed MM. However, the patient cohort who will derive maximum benefit from salvage ASCT is still undefined and is likely to evolve with increasing therapeutic options.
We aimed to evaluate the role of salvage ASCT in relapsed MM patients.
We performed a retrospective analysis of patients who underwent salvage ASCT for relapsed MM in South Australia between 1992 and 2011.
During this period, autologous stem cell transplants were performed for 457 patients with newly diagnosed MM. Thirty-nine patients subsequently underwent salvage ASCT for relapsed MM. The median age of patients at salvage ASCT was 59 (34–73) years, and 85% were ISS I and II at diagnosis. The majority of patients (90%, n=35) had a progression free interval (PFI) of at least 12 months after initial ASCT, consistent with recommendations by current literature. Salvage ASCT was performed for four patients with PFI shorter than 12 months, due either to suboptimal response to novel agents (thalidomide, lenalidomide, bortezomib), or the lack of novel agent availability in the earlier years.
The median progression-free survival (PFS) and median overall survival (OS) following salvage ASCT were 22 months (95% CI: 11–32) and 52 months (95% CI: 30–74) respectively. Non-relapsed mortality at 2 years was 7%. Following salvage ASCT, the median PFS (28 vs. 12 months, p = 0.006) and OS (83 vs. 26 months, p = 0.02) were significantly longer in patients whose progression free interval after the initial ASCT was > 24 months (Figures 1 and 2). Use of novel agents in salvage induction and maintenance therapy post salvage ASCT did not appear to influence outcome.
Our results suggest that there remains a role for salvage ASCT, even in the era of novel therapies. Salvage ASCT may result in durable responses, particularly in patients with longer progression free interval (> 24 months) following initial ASCT. This interval could be included as a selection criterion for patients with relapsed myeloma who remain transplant eligible.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.