Evaluating prescribing and access trends for adalimumab biosimilars in pediatric and adolescent care

The expiration of market exclusivity for Humira (adalimumab) in February 2023 led to the introduction of 10 biosimilars, raising questions about their impact on prescribing trends, payer responses, and formulary management in pediatrics. The primary objective of this study was to compare time to prior authorization approval between adalimumab biosimilars and the originator product during the first 2.5 years following biosimilar market entry. Secondary objectives were to describe the reason for switching adalimumab products in those already established on adalimumab therapy and to identify reported intolerances associated with biosimilar products.

To prepare for biosimilar launches, the clinical pharmacy team provided education to clinic staff and the health-system specialty pharmacy (HSSP), engaged with manufacturers to identify resources related to biosimilar products, and established prescribing workflows for patients on adalimumab. An observational study was then conducted from February 1, 2023, to June 30, 2025, across dermatology, gastroenterology, and rheumatology outpatient clinics of an integrated HSSP to assess biosimilar prescribing trends, time to authorization approval, and reason for switches. Included prescriptions were for patients naïve to adalimumab or switching between adalimumab products.

Evaluation of 350 prescriptions for adalimumab-naïve patients found that Humira was the preferred product for 290 prescriptions (82.9%). In adalimumab-naïve patients, the median time to prior authorization approval was 4 days (interquartile range [IQR], 2-9 days), with no significant difference between Humira (4 days; IQR, 2-10 days) and biosimilars (3 days; IQR, 2-9 days; P = 0.39). Among 256 prescriptions for non-adalimumab-naïve patients, the majority (86%) were for switches from Humira to a biosimilar, primarily due to formulary preference (77%), new insurance for the patient (11.3%), or exhaustion of copay card funds (4.7%).

Despite inherent complexities of biosimilar implementation, this study demonstrates that a coordinated, pharmacist-led approach supports timely access to therapy and minimizes treatment delays.