Will the emerging private-label market access channel help or hinder biosimilar market access?

Abstract

Until April 2024, adalimumab biosimilar uptake remained stagnant at 2% to 3%; the 3 largest pharmacy benefit managers (PBMs), which control 80% of prescriptions dispensed in the United States, maintained the reference product on formulary. That month, a major PBM changed its adalimumab formulary coverage policy, preferring 2 private-label biosimilars and 1 branded biosimilar, while excluding the reference product. The private-label biosimilar approach has since been adopted by the other 2 major PBMs, offering promise for biosimilar uptake, but seemingly only under the terms of the private-label arrangements. These arrangements may pose additional transparency issues for payers and plan sponsors, as well as barriers to biosimilar competition. The concerns raised by the emergence of the private-label channel apply not only to the adalimumab category but to ustekinumab and future biosimilars covered under the pharmacy benefit. Stakeholders concerned with biosimilar sustainability should monitor this situation as it continues to unfold for its effects on competition, conflicts of interest, and future biosimilar development.