Evaluating the access process for patients transitioning from intravenous to subcutaneous biologic administration for inflammatory bowel disease.

Background: Research is needed to evaluate challenges associated with payers' and patients' uptake of vedolizumab and infliximab subcutaneous (SC) formulations, which were recently approved by the U.S. Food and Drug Administration. Methods: A single center, ambispective study evaluated patients with inflammatory bowel disease with a referral to start or transition to SC vedolizumab or infliximab between September 2023 and December 2024. The primary outcome was time to SC formulation access. Secondary outcomes included whether patients were approved for SC therapy, method of approval, and number of patients not starting SC maintenance therapy after referral. Results: Of the 248 patients included in the regression analyses, most patients (72%) referred to SC were approved, with over half of those approvals occurring via prior authorization (56%). Of the 179 patients approved to start therapy, 21% of patients did not start therapy, largely due to patient decision (45%). The median time to access was 11 days (interquartile range 1-43) with a range of 0-457 days. Patients with commercial pharmacy insurance were 3 times more likely to have a longer time to medication access (odds ratios [OR]: 3.40, 95% confidence interval [CI]: 1.5-6.1, Conclusions: Over a quarter of patients prescribed SC vedolizumab or infliximab do not start due to payer restrictions or patient preference. Patients with commercial insurance may be less likely to access SC therapy.