Where are the interchangeable biosimilars?
In June 2017, Leah Christl, former biosimilar lead at FDA, told a conference in Chicago that interchangeable biosimilars were likely coming to the US market within two years.
And although no interchangeable biosimilar has been approved by FDA yet, and Christl has since moved on to Amgen, progress on interchangeable biosimilars has been slow in the intervening years.
Most recently, Boehringer Ingelheim announced that it has completed, as of last April, a switching study necessary for launching an interchangeable biosimilar for Humira (adalimumab), although the company did not offer any further details on the timing of its submission to FDA or whether there will be an advisory committee to review the data. Boehringer already has an adalimumab biosimilar approved by FDA, which it will launch in the US on 1 July 2023.
In addition, next March, insulin products will make the transition from being regulated under the FD&C Act to the PHS Act, which, according to former FDA Commissioner Scott Gottlieb means interchangeable insulin products are likely coming. FDA held a meeting in May on interchangeable insulins, which will be particularly important as only three follow-on insulin products — Basaglar, Lusduna and Admelog — have been approved since 2015.
But outside of the one potential adalimumab interchangeable and several possible insulin interchangeable products (none of which have been publicly disclosed), no other companies have even disclosed beginning a switching study. And although how such switching studies necessary for achieving this designation was only finalized last May, with FDA’s guidance on biosimilar interchangeability, companies have known about the switching study requirements since at least when the draft was released in January 2017.
Bernstein analyst Ronny Gal told Focus via email that Amgen and Sandoz have said they will pursue interchangeable biosimilars but switching studies have not listed yet.
Gottlieb also said recently in an interview that he believes the use of switching studies to get an interchangeability claim “is fairly efficient, but I think there’s things that you can continue to look at in terms of using real-world evidence [RWE] and looking at how you structure those switching studies to potentially make it more efficient.”
Anthony Maffia, head of regulatory affairs, North America at Sandoz, told Focus in a phone interview that he agrees with Gottlieb on the possible use of RWE, “but the way it’s applied needs flushing out.”
He also said he thinks the interchangeability designation is “creating an additional barrier to access, and we keep emphasizing that and feel strongly that it’s unique to the US and sets us apart from other global health authorities.”
A lot of the discussion on the savings from biosimilars is also centered on the fact that state pharmacy laws (45 states and Puerto Rico have passed legislation, according to Amgen) stipulate that biosimilars may only be substituted at the pharmacy if FDA has designated them as interchangeable to their reference products.
“Unless and until we change the way we pay for drugs more broadly, interchangeables are really the central path to real competition and lower prices,” Aaron Kesselheim, director of the Program on Regulation, Therapeutics and Law at Brigham and Women’s Hospital, Harvard Medical School, previously explained to Focus.
But many biologics are administered by physicians so the interchangeability designation will likely not be pursued in those instances. Others also have said interchangeables will not necessarily hit the market with as large of a discount as biosimilars without the designation.
In addition, there is a lot of room for misinformation among pharmacists and doctors. Hillel Cohen, executive director of scientific affairs at Sandoz, previously explained how an interchangeable biosimilar is not more highly similar than a non-interchangeable biosimilar, although the designation may provide the false perception of a better product.
Maffia added that he thinks FDA “absolutely” must clarify when certain companies are spreading misinformation on biosimilars. “We have to get to a common set of language and that’s something that FDA has a role in,” he said.
RAPS: First published in Regulatory Focus™ by the Regulatory Affairs Professionals Society, the largest global organization of and for those involved with the regulation of healthcare products. Click here for more information.