OBJECTIVES: To describe first-line treatment (1LT) patterns among patients with newly diagnosed multiple myeloma (NDMM), stratified by age group. METHODS: Patients with NDMM who did not receive stem cell transplant were identified from the MarketScan Commercial and Medicare claims databases (1/1/2009-9/30/2015). Patients had continuous medical/prescription coverage 12 months before (baseline) and ≥12 months after the index date of MM treatment initiation. Demographics and clinical characteristics were evaluated during baseline and 1LT patterns were compared among patients aged <65 and ≥65 years. Duration of 1LT and time to second-line treatment (2LT) were analyzed using Kaplan-Meier (KM) curves. RESULTS: Among the overall population with NDMM (n=3,238), 1,315 were <65 years old (mean=56.7 years), and 1,923 were ≥65 years old (mean=76.6 years). The average time from MM diagnosis until 1LT initiation was similar between age groups [2.8 vs. 3.0 months, p=0.52]. Proportions treated with triplet-, doublet-, and mono-therapy regimens in 1LT were 45.3%, 36.9%, and 10.5%, respectively, among younger patients versus 31.8%, 53.4%, and 10.9%, among older patients (p<0.001). Among younger patients, 22.7% were treated with immunomodulatory drug (IMiD)-based, 29.7% with proteasome inhibitor (PI)-based, and 38.8% with IMiD+PI combination regimens; among older patients, proportions were 32.1%, 35.1%, and 21.9%, respectively. Based on KM analysis, among younger patients median duration of 1LT was 8.8 months and time to 2LT was 32.3 months; among older patients, median duration of 1LT was 10.1 months and time to 2LT was 36.2 months. MM severity was not adjusted for due to limitations of the database. CONCLUSIONS: Treatment initiation occurred almost 3 months after initial MM diagnosis. Older patients were less likely to receive triplet or IMiD+PI regimens compared to younger patients. Average 1LT duration was 9-10 months. Future studies should investigate the influence of patient and physician preferences on time to treatment initiation and the implications on outcomes.