Results of Salvage Autologous Stem Cell Transplantation (ASCT) for Relapsed Multiple Myeloma (MM) in the Era of Novel Agents: Outcome of Patients (Pts) Receiving Prior Bortezomib (BTZ)-Based Therapy

Abstract

Background: A second (salvage) ASCT has frequently been offered to MM patients with relapsed disease who experience benefit from the first procedure. We have previously reported that pts undergoing a salvage ASCT in the era of VAD or thalidomide (thal) have a median progression-free survival (PFS) of 19 months (mos). The best results were observed in pts who experienced ≥ 2 year benefit after their first ASCT (Jimenez-Zepeda VH et al. Biol Blood Marrow Transplant 2012; 18: 773-9). However, the utility of this approach after the introduction of novel chemotherapeutic agents–such as bortezomib (BTZ)–remains unclear. Initially, provincial funding for BTZ in Ontario was provided only for relapsed disease. However, in 2007, the combination of either BTZ + dexamethasone (BTZ-dex) or cyclophosphamide, BTZ + dex (CyBorD) was adopted as the standard induction regimen for newly diagnosed pts before ASCT performed as part of first-line therapy. We now examine the results of salvage ASCT in our centre after the availability of BTZ.Methods: We used the Princess Margaret Myeloma Database to identify and characterize patients with relapsed MM who had received a bortezomib (BTZ)-based regimen for remission induction prior to their first ASCT or for re-induction before salvage ASCT. A retrospective chart review was performed to investigate the PFS and overall survival (OS) outcomes of these pts.Results: Between 01/2005 and 07/2015, 64 pts with MM who had previously received BTZ-based therapies underwent salvage ASCT for relapsed disease at our centre (Table 1). Median age was 56.9 yrs (range 37-67.3); 37 (58%) were male. ISS stage was 1 in 32 (50%), 2 in 16 (25%), 3 in 14 (22%) and NA in 2 (3%). The median interval between first and salvage ASCT for all pts was 48.6 mos (range 26.9-130.3), reflecting our policy of preferentially offering salvage ASCT to pts with at least a 2-yr benefit from the first transplant; the median time between re- induction therapy and salvage ASCT was 6.3 mos (range 0.3-95.9). Group A pts (n=27) had received BTZ-based therapy before their first ASCT; 48% of these also received BTZ-based regimens again prior to salvage ASCT. Pts in Group B (n=37) received BTZ-based regimens before the salvage transplant only, while induction therapy before the first ASCT consisted of VAD (21), dex alone (8), thal + dex or other regimens (5). Twenty-two (34%) of the pts received maintenance therapy between the first and salvage ASCT (most often thal-based), while 35 (55%) of the pts received maintenance therapy following salvage ASCT (most frequently lenalidomide [len]-based).The survival outcomes are summarized in Table 2. Median duration of follow-up (F/U) following salvage ASCT was 19.1 mos (range 0.8-96.4). One patient (1.6%) died several days following salvage ASCT. No other transplant-related mortality occurred. The median PFS following salvage ASCT was 19.1 mos (range 0.8- 87.5) with a median OS of 26.5 mos (range 0.8-101.9) in all pts. The median PFS after salvage ASCT was 15.8 mos for Group A and 25.2 mos for Group B pts.Conclusions: Even in the era of novel agents, salvage ASCT may provide PFS benefit to pts with relapsed MM who were previously treated with a BTZ-based regimen. However, the details of the optimal approach in this setting are not certain, including the impact of maintenance therapy given after the first and/or salvage ASCT. We are performing additional analyses of this population to try to identify factors associated with the best outcomes. [Display omitted] [Display omitted] [Display omitted] DisclosuresKukreti:Celgene: Honoraria; Lundbeck: Honoraria; Amgen: Honoraria. Prica:Janssen: Honoraria. Tiedemann:Novartis: Honoraria; Celgene: Honoraria; Takeda Oncology: Honoraria; BMS Canada: Honoraria; Amgen: Honoraria; Janssen: Honoraria. Trudel:Celgene: Honoraria; Novartis: Honoraria; Glaxo Smith Kline: Honoraria, Research Funding; Oncoethix: Research Funding. Reece:Merck: Research Funding; Takeda: Consultancy, Honoraria, Research Funding; BMS: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding.