What you need to know 

The U.S. Food and Drug Administration (FDA) has issued new draft guidance that eliminates the requirement for comparative efficacy studies in the approval of biosimilars. This change, if finalized, is expected to significantly reduce the time and cost associated with bringing biosimilars to market—potentially doubling or tripling the number of approvals in the coming years. The policy also proposes automatic interchangeability for all biosimilars, a move that could dramatically expand access and affordability for patients.

Prime Therapeutics (Prime) has long championed biosimilar reform as a key to improving affordability, access and innovation. The FDA’s new guidance aligns with our Save, Simplify, Support™ approach and affirms our long-term strategy to transform the specialty drug landscape.

Overview

On Oct. 29, 2025, FDA Commissioner Dr. Marty Makary announced sweeping reforms to the biosimilar approval process. Key elements of the new draft guidance include:  

• Elimination of comparative efficacy studies: Developers will no longer need to conduct clinical trials comparing biosimilars to reference products, provided chemical equivalence is demonstrated.
• Automatic interchangeability: All biosimilars would be considered interchangeable with their reference biologics, simplifying substitution at the pharmacy level.
• Support for domestic manufacturing: The FDA is encouraging onshoring of biosimilar production to strengthen supply chains.
• Accelerated timelines: The agency aims to cut months or even years from the approval process.

These proposed changes are part of a broader federal initiative to reduce drug costs and improve access to life-saving therapies, particularly as nearly 184 biologics are expected to lose exclusivity over the next decade.

Prime’s position 

The FDA’s new biosimilar guidance marks a pivotal moment in drug affordability and access; one that directly supports Prime’s long-standing strategy to accelerate biosimilar adoption. This policy shift reinforces our Save, Simplify, Support approach and validates our investment in a more efficient, client-aligned specialty drug model.  

• Save: Prime’s biosimilar strategy is built to deliver the lowest net cost for clients and members by aligning incentives across the supply chain and offering flexible, transparent pricing models. These efforts are designed to capitalize on the projected $180 billion biosimilar savings opportunity over the next five years and enable client and member benefits from the wave of biologics losing exclusivity. The FDA’s recent guidance further supports this direction by removing barriers that have historically slowed biosimilar adoption. To date, Prime’s commitment to supporting the uptake of biosimilars has saved clients more than $2 billion. 
• Simplify: Automatic interchangeability reduces complexity for prescribers and pharmacies. Prime has already implemented flexible biosimilar deployment models for drugs like Humira and Stelara, supported by tailored playbooks and benefit design strategies that minimize disruption and maximize savings. 
• Support: Prime has actively engaged with policymakers and industry partners to advocate for these reforms. Our conflict-free model, clinical rigor, and client-first approach ensure biosimilar adoption is both strategic and sustainable.

Looking ahead, Prime is preparing for the next wave of biosimilars with a roadmap that includes:

• Expanded private-label solutions 
• Enhanced reporting and analytics 
• End-to-end implementation support
• Strategic alignment with our evolved supply chain model

This policy shift represents a meaningful step forward and affirms Prime’s long-term vision that reinforces our commitment to delivering greater value through biosimilar innovation and client-aligned strategies.

Next steps 

Prime is actively reviewing the FDA’s draft guidance and assessing its potential implications for our clients and biosimilar strategy. While the announcement marks a significant policy shift, it is important to note that the guidance is not yet final and remains subject to the FDA’s regulatory review process. 

The agency has not provided a definitive timeline for finalization or implementation. Prime will continue to monitor developments closely and will share updates as more information becomes available. 

Questions 

If you have questions, please reach out to your Prime account team representative.