Novel agent induction therapy alone or followed by autologous stem cell transplantation in younger patients with multiple myeloma: A single-center retrospective study of 114 cases

To define the role of autologous stem cell transplantation (ASCT) in newly diagnosed multiple myeloma (MM) in the era of novel agents, we analyzed follow-up data of patients treated by these agents alone or followed by ASCT. From January, 2008 to December, 2012, 136 patients with de novo MM, aged <65 years, completed bortezomib- or thalidomide-based induction therapy and 114 patients achieved at least a partial response (PR). A total of 42 patients underwent ASCT. After a median follow-up of 39 months (range, 5-74 months), the median progression-free survival (PFS) was 23 months in the non-ASCT group vs. 42 months in the ASCT group (P=0.001), and the 5-year overall survival (OS) rate was 58.9 vs. 81.2%, respectively (P=0.03). The multivariate analysis revealed that complete response (CR) and maintenance therapy (MT) were independent factors of improved OS in both groups. Moreover, a subgroup analysis was performed according to the response status to evaluate the role of ASCT and MT. In the CR subgroup, neither ASCT nor MT exerted a significant effect on PFS or OS. In the very good PR subgroup, ASCT after MT (ASCT/MT) significantly improved PFS, but not OS. In patients exhibiting PR, ASCT/MT significantly prolonged PFS and OS. Therefore, ASCT in the era of novel agents maintains an important role in younger MM patients, particularly those achieving a PR after induction therapy. Furthermore, MT is a key factor associated with long-term survival in all MM patients.