Biosimilars are driving down costs and increasing access to biologics

Biosimilars will continue to reshape the market for biologics, with competition driving down costs overall. But patients are not yet consistently sharing in those savings, said James D. Chambers, Ph.D., a professor at Tufts University School of Medicine and an investigator at Tufts Medical Center. Chambers is a health economist and leads the Specialty Drug Evidence and Coverage (SPEC) Database.

Chambers said his team’s research has consistently shown that biosimilar competition puts significant downward pressure on the price of a molecule once a biosimilar enters the market, with declines reaching up to 70% over time in some cases.

But whether that translates into savings for patients depends heavily on benefit design, he said. Coinsurance-based cost sharing tends to pass savings through directly, but with more complex plan designs involving deductibles and copayments, patients don't always see the full benefit even as system-wide spending falls.

“Our work showed that biosimilars do have quite a significant downward pressure on costs. Competition from the biosimilars does lead to quite precipitous price decreases in some cases,” he said in an interview with Managed Healthcare Executive. “More work needs to be done to make sure that patients are seeing a reduction in their out-of-pocket payments alongside the biosimilars.”

Biosimilars have had a positive impact on patient access, providing more than 344 million incremental days of therapy, Chambers said. But he said we need to better understand where insurers are placing biosimilars on their formularies, as well as how utilization management, specifically step requirements, impacts access. “Biosimilars have led to an increase in access, but there’s a bigger opportunity for patients to have more rapid access to guideline-recommended care for many of these diseases,” he said.

Biosimilar impact on costs

It’s been more than 10 years since the first biosimilar was approved by the FDA: Zarxio (filgrastim-sndz), which references Neupogen and is used to treat neutropenia and boost infection-fighting white blood cells. Since then, the FDA has approved 89 biosimilars.

Related: PSG: Specialty drug spending predicted to increase 32% by 2028

Savings attributed to biosimilars are estimated to be $56.2 billion since the first biosimilar entry through 2024, according to the Association for Accessible Medicine. Biosimilar adoption has likely played a role in reducing the role of cost per claim in specialty drug trends, while new drug approvals and expanded indications for existing drugs have fueled increased specialty drug utilization, according to Pharmaceutical Strategies Group (PSG).

Overall biosimilar market share increased from 22.6% in 2023 to 56.3% in 2025, with Humira (adalimumab) biosimilars playing a major role, according to PSG. Humira biosimilars climbed from 0.3% market share in 2023 to 82.4% market share in 2025, while Stelara (ustekinumab) biosimilars reached 18% market share in their first year on the market.

The latest biosimilar market report from Samsung Bioepis finds that both the wholesale acquisition cost and the average sales prices of aflibercept are decreasing.

IRA's impact on biosimilar incentives

Chambers co-authored a paper published in November 2025 in Health Affairs Scholar that examined the unintended consequences of the Inflation Reduction Act’s Medicare price negotiation on biosimilars. The concern, he said, is that by subjecting a biologic to Medicare price negotiation, the law can undercut the commercial rationale for a company to invest in developing a biosimilar competitor in the first place. He said the policy shift stands in contrast to pre-IRA efforts to promote biosimilar competition, which he characterized as broadly positive for the market.

“What we really need is to use the IRA to focus on therapies that we're not expecting biosimilar competition for and take advantage of the biosimilar competition to drive down price,” Chambers said.

Although the IRA’s negotiation provision applies to Medicare, Chambers may extend to commercial insurance. A disincentive for biosimilar development would ultimately touch patients broadly, regardless of whether their coverage is through Medicare or a commercial plan, he said. Chambers said he is now studying prescription drug approval and development trends before and after the IRA's enactment to see whether a measurable change in biosimilar development has emerged.

Employers, health plans and pharmacy benefit managers have grown more willing to cover biosimilars as preferred products over time, according to Chambers, though adoption was initially slow. Research his team published in 2017 found only a small share of payer policies designated a biosimilar as the preferred product for a given molecule shortly after biosimilars began entering the market. That has changed, he said. Biosimilars now tend to be among the preferred options on many formularies, and patients often have a choice of several biosimilars for the same reference product, rather than a single option.

Looking ahead

Going forward, biosimilars will continue to reshape the biologics market, especially as newer therapies become available. Just yesterday, Biocon had announced that it launched Yesafili (aflibercept-jbvf), the biosimilar that references Regeneron's Eylea 2 mg to become available. Like Eylea, Yesafili is a vascular endothelial growth factor (VEGF) inhibitor used to treat various types of ophthalmology conditions, including neovascular (wet) age-related macular degeneration, macular edema following retinal vein occlusion, diabetic macular edema and diabetic retinopathy. Additional biosimilars of Eylea are expected to be available later this year and early in 2027.

Additionally, more pairs of biosimilars that reference Prolia, which treats osteoporosis, and Xgeva (enosumab), which prevents cancer-related bone events, are expected to be launched this year. So far, seven pairs have launched.

Also expected later this year are biosimilars of Johnson & Johnson’s Simponi (golimumab) and Simponi Aria, which treat patients with rheumatoid arthritis and ulcerative colitis. Immgolis and Immgolis Intri are interchangeable biosimilars that were developed by Bio-Thera Solutions and were approved in May 2026. The biosimilars will be marketed in the United States by Accord BioPharma, the U.S. specialty division of Intas Pharmaceuticals. They will be available in the fourth quarter of this year.