How to Encourage Interchangeable Biosimilars? Available, Global Reference Products and Meaningful Studies

In the United States, although the FDA has approved 9 biosimilar products to date, thus far, no biosimilar has sought or received an interchangeable designation. This designation would allow for pharmacy-level substitution, subject to state law.

Gillian Woollett, DPhil, MA, senior vice president of Avalere, recently authored an article suggesting ways that the FDA can facilitate applications and approvals for interchangeable biosimilars. Woollett’s suggestions comprise 3 key points: making reference products more readily available for conducting switching studies, applying scientific reasoning and clear international guidance on choosing a reference product, and encouraging the development and approval of all biologics.

According to the FDA’s draft guidance on achieving interchangeability, switching studies must be completed with a US-sourced reference. However, reference product sponsors can be hesitant to make their products available to biosimilar developers in the amounts necessary to administer switching studies. In order to address this issue, Woollett suggests that the FDA publicly reprimand drug manufacturers as well as pharmaceutical supply chain intermediaries that take part in withholding samples.

Furthermore, Woollett suggests that the FDA recognize a single version of a reference biologic that could act as a global reference for all biosimilar development as a way to eliminate costly bridging studies.

Finally, Woollett proposes that the FDA support scientifically meaningful studies that reduce the need for sponsors to generate costly data that are not eligible for regulatory decision-making; the need for confirmatory studies should be questioned, as they can delay access and increase costs.

Woollett’s suggestions are in line with some broader trends in the conversation about biosimilars, interchangeability, and competition; FDA Commissioner, Scott Gottlieb, MD, recently stated in an interview that he sees drug companies “gaming the system to try to block competition” in many ways within the current marketplace, and he wants to “end the shenanigans.” One ways to do so, said Gottlieb, is do away with expensive bridging studies.

The Trump administration has also weighed in on interchangeable biosimilars; in early February, the White House’s Council of Economic Advisors (CEA) called on the FDA to finalize its guidance on demonstrating interchangeability, saying that, “if these guidelines are relatively easy and inexpensive to adhere to, it could spur interchangeable applications and approvals, which could result in more effective competition with the reference biosimilar and lower prices.”

Congress has also been considering ways to address the issue of reference product sponsors withholding samples from biosimilar developers; the Creating and Restoring Equal Access to Equivalent Samples (CREATES) Act of 2016, which has yet to see a vote despite broad bipartisan support, would allow a generic or biosimilar drug developer to bring a civil action against the license holder of a reference drug if the latter declines to make available enough samples for testing as part of generic or biosimilar drug development.