Biosimilars are transforming access to life-saving treatments in the United States by offering safe, effective, and more affordable alternatives to originator biologics. With increasing FDA approvals and growing adoption, biosimilars are becoming a key pillar of the U.S. healthcare system. Here’s a comprehensive FAQ and status overview of biosimilars in 2025.

What Are Biosimilars?
Biosimilars are biologic medical products that are highly similar to an FDA-approved reference biologic, with no clinically meaningful differences in terms of safety, purity, and potency.
Unlike generic drugs, which are chemically synthesized and identical to their brand counterparts, biosimilars are made from living cells and are not identical but functionally equivalent to the original product.

How Are Biosimilars Approved in the USA?
The Biologics Price Competition and Innovation Act (BPCIA) of 2009 (enacted in 2010) established an abbreviated pathway under Section 351(k) of the Public Health Service Act for biosimilar and interchangeable biologics.
To gain approval, a manufacturer must provide:

• Comprehensive analytical data to prove high similarity
• Clinical and nonclinical safety and immunogenicity data
• Evidence showing no significant differences in therapeutic outcomes

For a biosimilar to gain interchangeability status, additional studies must show that alternating between the biosimilar and reference product poses no additional risks.

How Many Biosimilars Are Approved and Marketed in the USA (as of 2025)?
As of May 2025:

• 47 biosimilars have been approved by the FDA
• 36 biosimilars are currently marketed and sold in the U.S.
• These cover 15 reference biologics, including:
• Humira® (adalimumab)
• Remicade® (infliximab)
• Herceptin® (trastuzumab)
• Avastin® (bevacizumab)
• Neulasta® (pegfilgrastim)
• Enbrel® (etanercept)
• Eylea® (aflibercept) (newer approvals emerging in ophthalmology)

Biosimilars for insulin products, such as insulin glargine, have also gained popularity and usage under the new insulin biologics pathway.

How Many Biosimilars Are in Clinical Trials?
As of early 2025, there are:

• Over 80 biosimilar candidates in various stages of preclinical and clinical development
• Nearly 50 trials actively running in the U.S. for biosimilars targeting:
• Autoimmune diseases
• Oncology
• Ophthalmology
• Diabetes and endocrinology
• Rare diseases (orphan indications)

What Are the Economic and Healthcare Benefits?

• Cost Savings: Biosimilars have generated over $25 billion in savings for the U.S. healthcare system between 2015 and 2024.
• Increased Access: Lower costs have improved patient access to critical biologics, especially in underserved communities.
• Market Competition: Biosimilars drive down prices by introducing competitive pressure on monopolized markets.

What Is Interchangeability and Why Does It Matter?
Interchangeable biosimilars can be substituted for their reference product at the pharmacy without prescriber intervention (subject to state laws).
Currently:

• 11 biosimilars hold interchangeability status with their reference biologics.
• This is crucial for uptake in retail and specialty pharmacy settings, particularly for Humira® and insulin biosimilars.

What Challenges Remain?

• Provider Awareness & Confidence: Education is needed to overcome misconceptions about biosimilar safety and efficacy.
• Reimbursement Complexity: Insurance and pharmacy benefit manager (PBM) policies sometimes favor originator products due to rebate structures.
• Legal and Patent Litigation: Patent disputes can delay biosimilar market entry even after FDA approval.

What Does the Future Look Like?
With more biosimilars entering the pipeline and policies shifting toward value-based care, biosimilars are expected to:

• Capture 60–70% of the reference product market in some therapeutic areas
• Expand into ophthalmology, neurology, and rare diseases
• Lead to greater integration into Medicare Part D and Medicaid programs
• Benefit from continued regulatory clarity and support from the Biden administration’s price transparency and affordability initiatives