FDA Issues Draft Guidance Q&A on Biosimilar Interchangeability Submission Requirements

The FDA recently released a new draft guidance document to clarify submission procedures for applicants looking to gain licensing for a product seeking to be designated as an interchangeable biosimilar.

The question-and-answer document provides guidance for applicants as they formulate their submission documents in order to streamline the approval process.

Interchangeability designations are important to ensure patients have access to biosimilars as they allow for biosimilars to be administered in place of a reference product without a pharmacist needing to request approval from a physician first.

The FDA is accepting comments on the draft guidance until January 19, 2021. Guidance documents represent the agency's most current thinking about a subject, but are not legally binding.

In May 2019, FDA released long-awaited final guidance to clarify what data requirements are needed for a drug candidate to be licensed as an interchangeable biosimilar.

Gaining interchangeability status may require developers to conduct expensive and lengthy switching trials in additional to standard clinical trials, leading some physicians and researchers to call for the FDA to further revise their requirements. Currently, there are no biosimilars that have received this designation, however, a number of companies have expressed interest in seeking interchangeability status.

Information for New Biosimilar Applicants

For applicants who are submitting a biologics license application (BLA) under the 351(k) of the Public Health Services Act for a new biosimilar but also want to have an interchangeable designation, they should indicate that in an affirmative statement in the cover letter for the application.

“This approach provides for a more efficient and predictable review of BLAs,” wrote the FDA.

However, if an application contains sufficient information for a candidate to be licensed as a biosimilar but does not contain enough information to receive an interchangeability designation, the agency said that it would split the application, review the BLA as if it was only for biosimilar licensing, and update the applicant in a complete response letter of what supplement information is needed to obtain interchangeability.

Biosimilars Only If Interchangeable

The FDA also said that applicants can specifically request that the agency only license a drug candidate as a biosimilar if it is also deemed an interchangeable product by including the phrase “INTERCHANGEABLE-ONLY REVIEW” in the cover letter accompanying the BLA.

If the FDA needs to send a complete response letter to the applicant because of missing information, it will include deficiencies pertaining to licensing as a biosimilar and as an interchangeable biosimilar because a demonstration of biosimilarity is a required to receiving interchangeability approval.

Once an applicant receives a complete response letter, they “may then choose to amend and resubmit their application to address the deficiencies and support a demonstration of interchangeability or to amend and resubmit their BLA seeking licensure as a biosimilar product,” wrote the FDA.

BLA Holders and Labeling Statements

Under the guidance, applicants that already hold a BLA for a biosimilar should submit an original application to obtain interchangeability status under section 351(k). Applicants will still be able to market and distribute their biosimilar while their application is under review.

The FDA also included information on formatting labeling statements on interchangeability for BLA holders of an approved interchangeable biosimilar.