The launch of the US biosimilars market has been slow since the pathway for approvals was set up in 2010, with only five US Food and Drug Administration (FDA) biosimilar approvals, none of which have been approved as interchangeable biosimilars.
And though FDA cannot disclose what applications have been submitted to the agency due to confidentiality issues, FDA’s biosimilars lead Leah Christl said last week at DIA’s annual conference in Chicago that she expects interchangeable biosimilars will come to market within the next two years, though possibly sooner. And the first interchangeable biosimilar will likely be reviewed by an FDA advisory committee of outside experts, she confirmed.
According to the Biologics Price Competition and Innovation Act, which established the pathway by which biosimilars can be approved by FDA, an interchangeable biosimilar is biosimilar to its reference product and "can be expected to produce the same clinical result as the reference product in any given patient." Unlike in the EU, which does not use the interchangeable designation as all biosimilars
are considered interchangeable, in the US they can be substituted for their reference products without a doctor specifically calling for substitutions.
In January, FDA released its draft guidance on biosimilar interchangeability for consultation, explaining to companies how they can establish interchangeability, though companies sought further clarity.
Christl said FDA is reviewing industry's comments on the draft and will issue either revised draft guidance or final guidance within the next two years.
As far as biosimilar applications submitted to the agency, Christl confirmed that nine companies have publicly disclosed 14 applications.
But how interchangeable biosimilars will co-exist in the US market with non-interchangeable biosimilars remains to be seen. One analyst warned last year that there will be a lingering perception — no matter the lengths FDA and others go to make clear that the interchangeable is no more effective or safe than other biosimilars for the same reference product — that the non-interchangeable biosimilar is somehow inferior to the interchangeable biosimilar.
Moving forward, FDA’s work supporting biosimilar approvals will improve as the biosimilars user fee program is reauthorized, industry experts said. FDA will be able to hire more staff, enhance meetings with industry on their biosimilar applications and offer written responses to questions when meetings might not be necessary, among other improvements in the next user fee agreement.
Kimberly Greco, a director at Amgen, said the new written responses from FDA will make interactions with the agency easier.
In terms of advice for companies developing biosimilars, Hillel Cohen, an executive director at Sandoz, explained at DIA that companies should maximize the value of their meetings with FDA by clearly articulating questions to obtain specific agency guidance.