This past December, the U.S. Food and Drug Administration (FDA) issued a biosimilar industry guidance on a variety of topics. Mostly overlooked was a Q&A regarding safety protections in a 351(k) application. The FDA Commissioner thought the matter was important enough to single out in his comments released the same day, calling it a "critical issue."

FDA noticed that reference product holders have been limiting supplies of the reference drug to prospective 351(k) biologics license application (BLA) applicants, apparently in an effort to delay biosimilar applications.

Specifically, several companies have refused to sell the reference product, citing as justification the purported inability of the prospective applicants to follow the required risk evaluation and mitigation strategy (REMS) with elements to assure safe use (ETASU) safety standards. Without samples of the product, biosimilar sponsors cannot proceed with their BLAs.

In the Q&A, FDA commits to reviewing, upon request, study protocols submitted by a prospective 351(k) applicant to assess whether the included safety protections are comparable to those in the REMS with ETASU.

If FDA determines that the safety protections are comparable, the prospective applicant may request that FDA send a letter to the reference product holder stating that comparable safety protections exist and that FDA will not consider it a violation of the REMS to provide the prospective applicant with sufficient quantity of the reference product to allow it to perform the necessary testing in support of its 351(k) BLA. Requesting such a letter from FDA is not required.

So, if your company is being told by the reference product holder that it cannot provide the reference product to support your prospective 351(k) BLA due to its REMS programs, you now have an excellent remedy. A letter from FDA to the reference product holder assuring them that your safety protections are adequate will eliminate the use of this objection.