Early relapse post autologous transplant is a stronger predictor of survival compared with pretreatment patient factors in the novel agent era: analysis of the Singapore Multiple Myeloma Working Group.

The clinical outcome of multiple myeloma is heterogeneous. Both the depth of response to induction and transplant as well as early relapse within a year are correlated with survival, but it is unclear which factor is most relevant in Southeast Asian patients with multiple myeloma. We retrospectively analyzed outcomes of 215 patients who were treated with upfront autologous transplant in Singapore between 2000 and 2014. In patients who received novel agent (NA)-based induction, achieving only partial response (PR) post-induction was associated with poorer OS (HR 1.95, P=0.047) and PFS (HR 2.9, P<0.001), while achieving only PR post-transplant was strongly correlated with both OS (HR 3.3, P=0.001) and PFS (HR 7.6, P<0.001), compared with patients who achieved very good partial response (VGPR) or better. Early relapse was detected in 18% of all patients, although nearly half had initially achieved VGPR or better post-transplant. Early relapse after NA-based induction led to significantly shorter OS (median 22 months vs not reached, P<0.001), and was strongly associated with OS (HR 13.7, P<0.001). The impact of suboptimal post-transplant response and early relapse on survival may be more important than pretransplant factors, such as International Staging System or cytogenetics, and should be considered in risk stratification systems to rationalize therapy.