PBSA’s Statement on January 17th’s Draft Interchangeability Guidance


January 17, 2016

Patients for Biologics Safety and Access (PBSA) commends the FDA on today’s release of the draft interchangeability guidance, and looks forward to working with the agency to address a significant number of questions held by patients. PBSA has long believed that guidance on the interchangeability of biologic products is a necessity to ensure patient safety and to build patient confidence in the new category of therapies known as biosimilars. Today’s guidance document is a critical step on the path to providing that safety and confidence.

While PBSA is still processing the initial guidance document, there are a couple of areas where more explanation of the mechanism for designating interchangeability status is needed. Particularly:

·         How will FDA adequately assure patient safety if, as the draft allows, a product can be approved as interchangeable for a condition without clinical studies of the safety and efficacy for that condition based on extrapolation of data from other conditions?

·         How will required switching studies account for the fact that many patients take biologics for chronic conditions for many years and could be switched back and forth multiple times? Additionally, how will the FDA account for a future when there are multiple biosimilars and interchangeable products for the same reference product? Will the product have to be proven interchangeable with other interchangeable products for the same reference product? How will that affect the scope of switching studies when a biosimilar applies for an interchangeability designation?

·         In the guidance document, FDA states, “Post-marketing safety monitoring for an interchangeable product should also have adequate pharmacovigilance mechanisms in place. Rare but potentially serious safety risks may not be detected during pre-approval clinical testing because the size of the population exposed likely will not be large enough to assess rare events.” What specific additional requirements and resources will FDA put in place for post marketing surveillance beyond the current system for biosimilars and biologics?

·         Should the FDA require that the population examined through clinical testing be large enough to assess rare events? What specific resources and requirements will FDA put in place for post-marketing surveillance of interchangeable products?

·         Will the FDA require unique non-proprietary names for interchangeable products?   

While it is completing the draft interchangeability guidance, PBSA continues to call on FDA to take additional steps to protect patients from non-medical switching involving non-interchangeable biosimilars. We applaud FDA’s update to the Purple Book, which reads “…In contrast, FDA expects that a biosimilar product will be specifically prescribed by the healthcare provider and cannot be substituted for a reference product at the pharmacy level.” The phrase “at the pharmacy level”, however, is limiting and seemingly would allow switching at levels other than at the “pharmacy level”.

Given the agency’s previous statements on this topic and the recent actions by PBMs that appear to contradict the agency’s intentions, we encourage FDA to speak out and further clarify its position on this topic as soon as possible.

PBSA will provide further suggestions to the FDA on issues on which they have requested more public input in forthcoming comments on this guidance. Once again, we commend the FDA on its efforts to help ensure patient safety is paramount in the development of biosimilars.