Initiation of the Interchangeable Biosimilar Insulin Glargine-yfgn Among Older Adults

OBJECTIVE: The approval of the biosimilar insulin glargine-yfgn presents a cost-effective alternative for diabetes management. This study assessed insulin glargine-yfgn initiation among older adults using insulin glargine in Pennsylvania. STUDY DESIGN: This retrospective cohort study included insulin glargine users 65 years and older who were enrolled in Pennsylvania's Pharmaceutical Assistance Contract for the Elderly program from July 1, 2021, to June 30, 2023. METHODS: The primary exposure variable, prior insulin glargine use between July 1 and December 31, 2021, was classified into 5 categories: no use, Lantus alone, Basaglar alone, Toujeo alone, and multiple insulin glargine types. The main outcome, insulin glargine-yfgn initiation, was classified based on having at least 1 insulin glargine-yfgn (branded Semglee or unbranded version) prescription between January 1, 2022, and June 30, 2023. Chi-square tests and multivariate logistic regression were used to examine factors associated with insulin glargine-yfgn initiation. RESULTS: Among 6866 patients, 3.7% initiated insulin glargine-yfgn. Insulin glargine-yfgn initiators were less likely than noninitiators to have previously used Lantus, Basaglar, or Toujeo. They were more likely to reside in rural counties (adjusted OR [AOR], 1.39; P = .0135), be in long-term care facilities (AOR, 2.10; P = .0069), and have multiple prescribers (≥ 3 prescribers: AOR, 3.23; P < .0001) compared with noninitiators. Only 1.6% of insulin glargine prescriptions were for insulin glargine-yfgn, with relatively more prescriptions filled at nursing home pharmacies and written by physicians. CONCLUSIONS: Insulin glargine-yfgn use among older adults is low despite its cost-effectiveness. Overcoming barriers related to prescribing patterns, formulary placement and reimbursement challenges, and pharmacy channels could improve insulin glargine-yfgn adoption, reducing diabetes care costs.