Milestone Approvals, Evolving PBM Models May Redefine 2026 Biosimilar Landscape

Stakeholders across the US health care system navigated a maturing biological market that reached a significant milestone of 90 total approvals by the end of 2025.¹ This progress, detailed in a recent industry report from Samsung Bioepis, highlighted how the biosimilar sector moved beyond early-stage growth into a complex era of high market penetration and shifting financial incentives.²

The US biosimilar market evolves with 90 approvals, significant price drops, and new PBM models enhancing access to cost-effective therapies. | Image Credit: © ipopba - stock.adobe.com

As of December 2025, the FDA had cleared biosimilars for 20 unique biological molecules, with 63 of those 90 approvals (70%) successfully reaching the commercial market. These launches led to substantial price reductions over time; on average, the average sales price for biosimilars decreased by 52% within 5 years of the initial class launch. In more mature therapeutic areas, these price reductions reached as high as 77%.

Market adoption patterns revealed a distinct divide between "fast" and "slow" uptake markets. Oncology, ophthalmology, and pegfilgrastim biosimilars were categorized as fast-uptake products, achieving an average market share of 81% within 5 years of launch. In contrast, sectors such as immunology, filgrastim, and insulin glargine saw much slower adoption, averaging only a 25% market share in the same timeframe. By the third quarter of 2025, specific molecules like bevacizumab and trastuzumab reached biosimilar market shares of 92% and 88%, respectively.

Despite these gains, the industry faced significant issues regarding traditional pharmacy benefit management (PBM) contracting. Historically, the PBM model favored high-wholesale acquisition cost (WAC), high-rebate products because those products contributed more heavily to the "rebate guarantees" that PBMs promised to self-funded employers. This structure created a "rebate trap" where a lower-cost biosimilar might have a lower net price than the reference biologic but was excluded from formularies because it did not provide the necessary rebate volume to satisfy aggregate contractual guarantees.

In 2026, however, the report pointed to a critical shift toward fiduciary and transparent PBM models. These emerging frameworks prioritized trend management and cost control over rebate maximization. Some PBMs introduced "rebate credits," which allowed the price difference between a reference product and a biosimilar to count as a "phantom credit" toward rebate guarantees, effectively removing a major barrier to biosimilar adoption.

Thomas Newcomer, vice president and head of US commercial operations at Samsung Bioepis, commented on these systemic changes in the report's press release: “As the US healthcare market enters 2026, stakeholders’ approaches to prescription drug pricing and management continue to evolve. Alongside established PBM contracting structures, new models emphasizing alternative pricing reimbursement, transparency, and a shift towards more fiduciary responsibility have emerged in response to changing market conditions.”³

Specific therapeutic areas also faced unique challenges as 2026 began.¹ In the ophthalmology space, although 4 aflibercept biosimilar products are awaiting clearance to launch, the reference product faces only 1 competitor offering a 12% WAC discount. Meanwhile, the immunology sector saw a proliferation of complex pricing strategies; while private label brands became common for adalimumab and ustekinumab, most ustekinumab manufacturers avoided the dual "high WAC/low WAC" strategy that characterized the adalimumab market in previous years.⁴

Looking forward through 2026, the continued erosion of reference product dominance appeared likely as PBMs pledged fuller rebate pass-throughs by 2028 and more employers adopted biosimilar-first strategies.¹ These shifts suggested that the primary challenge for the industry was no longer demonstrating clinical parity but rather aligning financial incentives to ensure that the most cost-effective therapies reached the patient.

References

1. Biosimilar approvals. The Center for Biosimilars^®. Updated December 22, 2025. Accessed January 27, 2026. https://www.centerforbiosimilars.com/biosimilar-approvals
2. SAMSUNG BIOEPIS: Biosimilar market report 12th edition, Q1 2026. January 23, 2026. Accessed January 27, 2026.
3. Samsung Bioepis releases Q1 2026 US biosimilar market report. News release. Samsung Bioepis. January 23, 2026. Accessed January 27, 2026. https://www.samsungbioepis.com/en/newsroom/newsroomView.do?idx=531&currentPage=1
4. Jeremias S. Happy birthday adalimumab biosimilars: reflecting on the first year of US competition. The Center for Biosimilars. January 31, 2024. Accessed January 27, 2026. https://www.centerforbiosimilars.com/view/happy-birthday-adalimumab-biosimilars-reflecting-on-the-first-year-of-us-competition