Improved survival of multiple myeloma patients treated with autologous transplantation in the modern era of new medicine.

Abstract

New drugs for multiple myeloma (MM) have dramatically improved patients overall survival (OS). Autologous stem cell transplantation (ASCT) remains the mainstay for transplant-eligible MM patients. To investigate whether the post-ASCT prognosis of MM patients has been improved by new drugs, we conducted a retrospective observational analysis using the Transplant Registry Unified Management Program database in Japan. We analyzed 7,323 patients (4,135 men, 3,188 women, median age 59, range 16-77 years) who underwent upfront ASCT between Jan. 2007 and Dec. 2018. We categorized them by when they underwent ASCT according to the drugs introduction in Japan: group 1 (2007-2010), group 2 (2011-2016), and group 3 (2017-2018). We compared the groups post-ASCT OS. The 2-year OS rates (95%CI) of groups 1, 2, and 3 were 85.8% (84.1-87.4%), 89.1% (88.0-90.1%), and 92.3% (90.0-94.2%) (p<0.0001) and the 5-year OS (95%CI) rates were 64.9% (62.4-67.3%), 71.6% (69.7-73.3%), and not applicable, respectively (p<0.0001). A multivariate analysis showed that the post-ASCT OS was superior with these factors: age <65, performance status 0/1, low International Staging System (ISS) stage, receiving SCT ≤180 days post-diagnosis, better treatment response pre-ASCT, later year of ASCT, and receiving SCT twice. A subgroup analysis showed poor prognoses for the patients with unfavorable karyotype and poor treatment response post-ASCT. The post-ASCT OS has thus improved over time (group 1<2<3) with the introduction of new drugs for MM. As the prognosis of high-risk-karyotype patients with ISS stage III remains poor, their treatment requires improvement.