Autologous stem cell transplantation is safe and effective for fit older myeloma patients: exploratory results from the Myeloma XI trial

Autologous stem cell transplant (ASCT) remains standard of care for consolidation after induction therapy for eligible newly diagnosed myeloma patients. In recent clinical trials comparing ASCT to delayed ASCT, patients aged over 65 were excluded. In real-world practice stem cell transplants are not restricted to those aged under 65 and clinicians decide on transplant eligibility based on patient fitness rather than a strict age cut off. Data from the UK NCRI Myeloma XI trial, a large phase III randomised controlled trial with pathways for transplant-eligible (TE) and ineligible (TNE) patients, was used in an exploratory analysis to examine the efficacy and toxicity of ASCT in older patients including analysis using an agematched population to compare outcomes for patients receiving similar induction therapy with or without ASCT. Older patients within the TE pathway were less likely to undergo stem cell harvest at the end of induction than younger patients and of those patients undergoing ASCT there was a reduction in PFS associated with increasing age. ASCT in older patients was well tolerated with no difference in morbidity or mortality between patients aged <65 years, 65-69 and 70-75. In an age-matched population of patients including those in both the TE and TNE pathways there was a significant advantage associated with undergoing ASCT with an increase in PFS (HR 0.41, p <0.0001) and OS (HR 0.51, p <0.0001), which persisted even after adjustment for baseline covariates including those related to frailty and response to induction. These findings support the use of ASCT for selected, fit older myeloma patients.