Background: Evidence supports that MT after ASCT provides a progression free and overall survival advantage in MM compared to placebo in phase III trials. Lenalidomide was recently approved for this purpose by both the Food and Drug Administration and the European Medicines Agency in 2017. However, there is the potential that continual treatment will have a negative impact on patient QoL. Very few studies have assessed this; although a recent study found no significant QoL differences between patients receiving MT vs no MT post ASCT. Further data are required to confirm this.Objective: To assess the impact of active MT vs. no MT on the QoL of patients with MM following first ASCT.Methods: A non-interventional, cross-sectional study was conducted with patients recruited from 13 centers in the United States and Canada. All patients had received a single ASCT and three groups were identified and compared: •Patients within 30-100 days of ASCT and had not commenced any MT (baseline patients)•Patients at >100 days post ASCT and currently receiving any MT therapy (MT patients)•Patients at >100 days post ASCT and currently not receiving MT (no MT patients)Patients were excluded from this analysis if they had experienced clinical progression post ASCT.Demographics, clinical characteristics, comorbidities, treatment and symptoms were captured via a case report form. Patients completed a questionnaire containing the EuroQoL five dimension (EQ-5D), the European Organization for Research and Treatment of Cancer QoL Questionnaire Core 30 (EORTC QLQ-C30) and the QoL Questionnaire Myeloma 20 module (QLQ-MY20). Differences in QoL between baseline, MT and no MT patients were explored with ordinary least squares regressions, controlling for age, sex, body mass index, time since diagnosis, stage at diagnosis, comorbidities, Eastern Cooperative Oncology Group performance status and country.Results: Between 2016 - 2017, 13 sites in the US and Canada enrolled 303 patients (excluding 3 patients who had progressed). Mean age was 62.0 years, 45% were female. There were 84, 141 and 78 baseline, MT and no MT patients respectively. Baseline patients were a mean of 83.7 days post ASCT whereas mean days post-transplant was 868.6 for MT patients and 905.2 for no MT patients. The majority of MT patients (81.6%) received lenalidomide either as monotherapy or combination therapy. Unadjusted mean EQ-5D scores were 0.77 for baseline patients, 0.81 for MT patients and 0.79 for no MT patients, with higher scores indicating better QoL.In the adjusted analysis, EQ-5D and the majority of EORTC scores did not significantly differ between the three patient groups. However, EORTC global scores demonstrated a significant QoL improvement relative to baseline for both MT (+9.62, p=0.0178) and no MT (+10.06, p=0.0435) patients. A similar pattern was observed for social functioning (MT vs. baseline; +12.65, p=0.0106. No MT vs. baseline; +16.94; p=0.0055) and the MY-20 body image domain (MT vs. baseline, +16.78, p=0.0053; No MT vs. baseline, +19.31, p=0.0083). Only the diarrhea domain from the EORTC-QLQ C30 and future perspectives from the MY-20 (measuring concerns about outlook and future health) differentiated between MT vs. no MT patients; with patients on MT reporting higher scores for diarrhea (greater problems, [+9.43; p=0.0358]) and lower scores for future perspectives (poorer outlook, [-11.39; p=0.0196]).Conclusion: QoL after ASCT improves from baseline for both MT and no MT patients as measured by the global health status and social functioning domains of the EORTC QLQ-C30, and the body image domain from the MY-20. Only outcomes on future perspectives and diarrhea differentiated between MT and no MT patients. Collectively, the results suggest that MT is not associated with a notable QoL detriment. DisclosuresVij:Takeda: Honoraria, Research Funding; Abbvie: Honoraria; Bristol-Meyers-Squibb: Honoraria; Janssen: Honoraria; Jazz: Honoraria; Celgene: Honoraria; Amgen: Honoraria, Research Funding; Konypharma: Honoraria. Norkin:Celgene: Honoraria, Research Funding. Kumar:Celgene, Millennium, BMS, Onyx, Janssen, Noxxon, AbbVie, Amgen, Merck, Oncopeptides, Skyline Diagnostics, Takeda: Consultancy; Skyline: Honoraria; Celgene, Millennium/Takeda, Onyx, AbbVie, Janssen, Sanofi, Novartis, Amgen, Genentech, Merck, Oncopeptides, Roche, Skyline Diagnostics: Research Funding. Roberts:Adelphi Real World: Employment. White:Amgen, Celgene, Janssen, Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Wood:Adelphi Real World: Employment. Blanthorn-Hazell:Adelphi Real World: Employment. Rossi:Thrassos: Consultancy; Celgene: Consultancy. Dhanasiri:Celgene Corporation: Employment, Equity Ownership. Zafar:Celgene Corporation: Employment. Newhouse:Celgene: Employment. Arleigh:Celgene: Honoraria.