Abstract
BACKGROUND: In 2014, the US Food and Drug Administration approved the first glucagon-like peptide-1 (GLP-1) receptor agonist product, liraglutide injection, for obesity treatment. Many GLP-1 obesity treatment clinical trials report significant weight loss and medication adherence at more than 85%. Little is known about the real-world GLP-1 obesity treatment adherence, persistence, and switch rates. OBJECTIVE: To measure GLP-1 therapy persistence, adherence, and switch rates in a real-world cohort of members without diabetes using these drugs for obesity treatment. METHODS: Integrated pharmacy and medical claims data from 16.5 million average monthly commercially insured membership were used to identify obese members without diabetes newly initiating GLP-1 therapy between January 1, 2021, and December 31, 2021. Members were required to be continuously enrolled 1-year before and after the GLP-1 therapy start date and aged 19 years of age or older. Persistence was measured as no greater than or equal to 60-day gap with allowance for GLP-1 switching. Adherence was measured as the proportion of days covered (PDC) and members with a PDC greater than or equal to 80% were considered adherent. GLP-1 product switching was also assessed descriptively. RESULTS: 4,066 commercially insured obese members without diabetes that newly initiated GLP-1 therapy met all study criteria. The mean age was 46 years, and 81% were female. Overall, GLP-1 persistence was 46.3% at 180 days and 32.3% at 1 year. The highest and lowest persistence rates at 1 year were observed for semaglutide (Ozempic) at 47.1% and liraglutide (Saxenda) 19.2%, respectively. Average PDC during the 1-year assessment was 51.0% with 27.2% adherent to therapy and 11.1% switched GLP-1 drugs. CONCLUSIONS: This GLP-1 weight loss treatment real-world analysis, among obese individuals without diabetes, found poor 1-year persistence and adherence and low rates of switching between products. These findings will aid in assessing products cost-effectiveness, understanding obesity care management program needs, forecasting future GLP-1 use and cost trends, and negotiating GLP-1 pharmaceutical manufacturer value-based purchasing agreements.