Biosimilars have transformed the biologics market over the past decade, lowering costs but not always ensuring patients benefit directly, health economist James D. Chambers said.
Chambers, a professor at Tufts University School of Medicine and investigator at Tufts Medical Center, noted that competition from these drugs has reduced prices by up to 70% in some cases. Patient savings, however, depend on how insurers design their coverage.
“Biosimilars create strong downward pressure on costs,” Chambers said in an interview. “More effort is needed to ensure patients also pay less out of pocket.”
Market growth and cost savings
The FDA approved the first biosimilar, Zarxio (filgrastim-sndz), in 2015. Since then, the agency has cleared 89 of these drugs, which have saved $56.2 billion through 2024, according to the Association for Accessible Medicine.
Market share for biosimilars has climbed sharply, rising from 22.6% in 2023 to 56.3% two years later. Humira (adalimumab) biosimilars saw an even steeper increase, jumping from 0.3% to 82.4% in the same period. Stelara (ustekinumab) biosimilars captured 18% of the market in their first year.
These drugs have expanded patient access, providing over 344 million additional days of therapy. Insurers’ formulary decisions and policies like step therapy, however, can still delay access to recommended treatments.
The Inflation Reduction Act’s Medicare price negotiation rules may be creating new challenges. A 2025 study in Health Affairs Scholar, co-authored by Chambers, suggested the law could reduce incentives for companies to develop biosimilars for drugs already subject to negotiation.
Before the IRA, policies generally supported biosimilar competition. While the law’s negotiation rules apply only to Medicare, the effects could extend to commercial insurance, limiting savings for all patients.
New biosimilars on the horizon
Biocon launched Yesafili (aflibercept-jbvf), a biosimilar for Regeneron’s Eylea, which treats wet age-related macular degeneration. Additional Eylea biosimilars are expected later this year and in early 2027.
This year will also bring biosimilars for Prolia and Xgeva (denosumab), used to treat osteoporosis and prevent cancer-related bone complications. Seven versions of these drugs have already reached the market.
Biosimilars for Johnson & Johnson’s Simponi (golimumab) and Simponi Aria will debut later this year. Immgolis and Immgolis Intri, developed by Bio-Thera Solutions and approved in May 2026, will be marketed by Accord BioPharma in the fourth quarter.
Insurers and pharmacy benefit managers have become more open to covering biosimilars as preferred options. Research by Chambers found that in 2017, few payer policies favored these drugs. Today, they often appear as top choices on formularies, with patients sometimes selecting from multiple versions of the same reference product.
The full benefits of biosimilars may not materialize if policy changes discourage further development. Chambers is studying whether the IRA has already slowed approvals by comparing trends before and after the law took effect.
The market keeps growing, yet it remains unclear whether patients will experience the same financial relief as the healthcare system.
Experts note that changes in cognitive function later in life may influence how patients manage long-term medication costs.
