FDA Proposes Major Overhaul of Biosimilar Approval Process, Eliminating Most Clinical Studies
核心洞察
The FDA issued two draft guidance documents in October 2025 that would largely eliminate clinical efficacy and switching studies for biosimilar (搜索) approvals, relying instead on modern analytical methods.
The policy changes effectively collapse the distinction between biosimilarity and interchangeability, with high-quality analytical comparability paired with pharmacokinetic and immunogenicity assessments generally sufficient for approval.
FDA plans to finalize the guidance documents by early 2026 and may begin approving all non-vaccine biosimilars as interchangeable, potentially accelerating market access.
The Food and Drug Administration has proposed sweeping changes to biosimilar (搜索) development that would eliminate most clinical studies and fundamentally reshape how these lower-cost alternatives to biologic drugs reach the market. The agency issued two draft guidance documents in October 2025 that would rely primarily on advanced analytical methods rather than human clinical trials to demonstrate biosimilarity and interchangeability.
Streamlined Approval Pathway
Under the proposed framework, FDA would waive comparative efficacy studies (CES) for most therapeutic proteins, including monoclonal antibodies (搜索). Instead, high-quality analytical comparability data paired with pharmacokinetic similarity studies and immunogenicity assessments would generally suffice to demonstrate biosimilarity. FDA explained that "modern analytical tools can more sensitively detect and characterize differences between a proposed biosimilar (搜索) and its reference product, making CES generally unnecessary to show biosimilarity, particularly for therapeutic proteins."
The changes build on FDA's June 2024 interchangeability draft guidance, which proposed eliminating clinical switching studies between reference products and proposed biosimilars. According to the agency, "given the precision of current analytical methods and accumulated experience showing the risk from switching is insignificant, clinical switching studies are generally no longer needed to demonstrate interchangeability."
Collapsing Regulatory Distinctions
The draft guidance documents effectively merge the requirements for biosimilarity and interchangeability designations. FDA Commissioner Marty Makary stated that the agency believes "all biosimilars should be interchangeable," suggesting FDA may begin approving biosimilars as interchangeable regardless of whether applicants specifically request that designation.
HHS Secretary Robert F. Kennedy, Jr. indicated that HHS will apply "the same procedure that is used for small molecule drugs" to biosimilars, though vaccines are excluded from the proposals due to their lack of placebo-controlled, randomized safety trials.
Market Impact and Economic Implications
An August 2025 study by the Eastern Research Group (搜索) for the Department of Health and Human Services (搜索) found that current clinical study requirements have increased biosimilar (搜索) development time and costs. The study concluded that the distinction between "biosimilar" and "interchangeable" has contributed to "poorer market uptake [of biosimilars] in the United States compared to [generic drugs]" by creating perceived differences in safety and efficacy.
The research determined that designating all approved biosimilars as interchangeable would materially increase expected net present value and that eliminating comparative efficacy studies "can lead to cost savings and an increase in lifetime ENPV in large markets."
Exclusivity Considerations
The proposed changes could significantly impact first interchangeable exclusivity (FIE) rights under the Biologics Price Competition and Innovation Act. Currently, FIE bars FDA from approving another interchangeable for periods ranging from 18 to 42 months after approval, depending on patent litigation outcomes.
If FDA begins automatically approving biosimilars as interchangeable, FIE could shift from the first approved biosimilar (搜索) that requested interchangeability to simply the first approved biosimilar to a reference product. This may result in companies "altering their launch sequences of biosimilars or intensifying their development efforts for certain biosimilars as they race to be the first approved."
Implementation Timeline
Commissioner Makary stated that FDA plans to finalize both guidance documents within the first half of 2026 to align the biosimilars pathway more closely with the generics model. The U.S. Federal Trade Commission (搜索) has commented favorably on the proposals, noting they "would lower barriers to entry, simplify the approval process, help to dispel the false impression of separate safety and efficacy standards for interchangeables and other biosimilars, and foster increased competition in biologic marketplaces."
While clinical efficacy studies would become the exception rather than the rule, FDA noted they may still be required in limited cases, such as for intravitreally administered products or where comparative clinical studies with clinically relevant endpoints other than efficacy may be informative.