By reducing redundant pharmacokinetic testing requirements, the FDA estimates biosimilar developers could cut study costs by up to 50%.


RT’s Three Key Takeaways:

  1. FDA Streamlines Biosimilar Development: The US FDA issued new draft guidance recommending the removal of certain unnecessary clinical pharmacokinetic (PK) studies when scientifically justified to accelerate biosimilar development.
  2. Lower Development Costs and Drug Prices: By reducing redundant PK testing requirements, the agency estimates biosimilar developers could cut study costs by up to 50%—around $20 million—potentially helping expand access to lower-cost alternatives to expensive biologic medicines.
  3. Updated Policy Reflects Evolving Experience: The guidance updates implementation of the Biologics Price Competition and Innovation Act and allows the use of non-US comparator products in certain cases, reflecting the FDA’s growing experience reviewing biosimilars, with 82 products approved so far.


The US FDA issued new draft guidance recommending streamlining unnecessary clinical pharmacokinetic (PK) testing when scientifically justified. The agency says the guidance is another major step in its initiative to streamline the development of biosimilar medicines, which are like “generic” versions of biologic drugs.

The change could save biosimilar developers up to 50% of their PK study costs, or approximately $20 million, and help lower drug costs, the FDA says.

“Streamlining biosimilar development reflects our ongoing commitment to lowering drug costs for everyday Americans,” said FDA Commissioner Marty Makary, MD, MPH. “Using common sense, we are embracing more precise analytical testing approaches than have been used in the past.”

Biologic medicines can be powerful treatments for many diseases, including autoimmune diseases and cancer, but are often expensive. Despite accounting for just 5% of prescriptions, biologics account for 51% of drug spending, and commonly cost hundreds of thousands of dollars per year. Biosimilars, like generic drugs, can give patients more affordable treatment options and increase access to medications that are otherwise unaffordable.  

Today’s announcement builds on a prior FDA effort in October, where Commissioner Makary announced another draft guidance reducing certain unnecessary comparative efficacy studies, which can require 1-3 years and cost $24 million.

The new draft guidance, “New and Revised Draft Q&As on Biosimilar Development and the BPCI Act (Revision 4)” is intended to inform prospective applicants and facilitate the development of proposed biosimilars and proposed interchangeable biosimilars. It revises and replaces the draft guidance for industry entitled “New and Revised Draft Q&As on Biosimilar Development and the BPCI Act (Revision 3)” issued September 17, 2021, and includes revisions to certain Q&As that appeared in a previous version of the final guidance entitled “Questions and Answers on Biosimilar Development and the BPCI Act.”

Specifically, this draft guidance provides updated recommendations to prospective biosimilar applicants seeking to use data from a comparator product approved outside the U. (“non-US-licensed comparator product”) as evidence that a proposed product is biosimilar to the US-licensed product. The recommendations describe scenarios in which a biosimilar applicant may use clinical data from outside the US without additional data from a three-way PK study (using the proposed biosimilar, the US-licensed reference product, and the non-US-licensed comparator product). The revisions also remove the earlier recommendation for at least one clinical PK study that directly compares the proposed biosimilar with the US-licensed reference product to support a demonstration of biosimilarity; instead, a PK study can use a comparator product approved outside the US if scientifically justified.

The agency today is withdrawing final guidance titled “Scientific Considerations in Demonstrating Biosimilarity to a Reference Product,” because it no longer represents the FDA’s current thinking. Since the issuance of this guidance in April 2015 (when the agency had approved only one biosimilar application), the agency has gained significant experience with review of proposed biosimilars and its scientific thinking has evolved.

The Biologics Price Competition and Innovation Act of 2009 created an abbreviated licensure (approval) pathway to help provide patients with greater access to safe and effective biological products. To date, the FDA has approved 82 biosimilars that provide Americans with additional affordable treatment options for conditions such as cancer, rheumatoid arthritis, diabetes, Crohn’s disease, and osteoporosis.