The FDA rolled out much-awaited biosimilar interchangeability draft guidelines Tuesday, tipping its hand to developers looking to challenge sales of the world’s top biologics. The gist? Winning the designation won't be easy, but a big payoff could await for those who do.
Together, the guidelines (PDF) outline requirements for biosimilar developers looking to prove that their versions are interchangeable with the original brands. If deemed so, branded scripts could be filled with biosims instead without the prescribing doctor's approval, similar to generic versions of traditional meds.
But the requirements for that designation, according to analysts, appear to be more stringent than biosim makers would like. The current draft would require switching studies more complicated than many now in the works, for instance.
Barclays analysts wrote Tuesday that the draft guidelines set a “high bar” to win interchangeability, “most notably requiring switching studies include two exposure periods for each product.”
Biosim developers can take comfort knowing that interchangeability isn’t required for an approval, the analysts pointed out, as knockoff versions now on the market attest, including Novartis' first-to-market biosim Zarxio. Nor will interchangeability “be necessary for commercial adoption,” they said; indeed, pharmacy benefits managers' 2017 formularies have excluded some originator brands in favor of recently approved biosims.
“However, the draft guidance suggests we might be waiting longer before seeing an interchangeable biosimilar come to market,” Barclays pointed out.
Despite the details in the document, however, Bernstein analyst Ronny Gal wrote that the “main value of the guidelines is in their actual release” as companies working on biosims can now seek interchangeability. Novartis, for one, has stated interchangeability as a primary goal of its biosim efforts, Gal wrote.
Notably, based on information publicly available, no Humira biosim developers have study designs that would meet the interchangeability requirements of the draft guidelines, according to Barclays. Amgen has an approved Humira biosimilar in Amjevita, while Novartis, the Merck Group and Momenta are working on their own versions.
“Some of this may be due to the fact that sponsors are not required to fully disclose [trial] designs, and we expect developers have been receiving informal guidance from FDA during regular development-stage meetings,” the analysts wrote in a note Tuesday.
Gal figures the guidelines “will make it hard for non-interchangeable biosimilars to sell when an interchangeable one is available.” He pointed out that first-entrant biosims could be “supplanted” as companies with follow-up products shoot for the designation.
The FDA is seeking comment on the draft for 60 days before forming its final interchangeability rules. The guidelines come at a key time for the industry, as many of the world's top drugs face biosim threats in the coming years.