More Clinical Study Evidence That Biosimilar Switching Carries a Low Risk

A literature review published this past weekend in Drugs reaffirms what most parties interested in biosimilars suspect—that switching from a reference product to biosimilar is not a significant clinical concern. Biosimilar switching was not generally associated with poorer outcomes.

The study evaluated the results of 90 clinical studies comprising more than 14,000 patients with 14 diseases or conditions. The authors from Novartis (and its Sandoz subsidiary), the Oregon Medical Research Center, Rocky Mountain Cancer Centers, IBD Center of Humanitas Clinical and Research Hospital (Milan), and Avalere Health stated that “the great majority of the publications did not report differences in immunogenicity, safety, or efficacy [as a result of biosimilar switching]. The nature and intensity of safety signals reported after switching from reference medicines to biosimilars were the same as those already known from continued use of the reference medicines alone.” In addition, they reported, “Three large multiple switch studies with different biosimilars did not show differences in efficacy or safety after multiple switches between reference medicine and biosimilar.”

In this evaluation, the biosimilars tested included those for infliximab, epoetin, filgrastim, growth hormone (which has not been considered a biosimilar in the Ubiosimilar switchingS), etanercept, and adalimumab. Infliximab was the subject of the majority of the clinical studies.

Of the 90 studies, two were outliers, suggesting potential safety issues associated with biosimilar switching. One was described as a 2016 retrospective study of a claims database from Turkey, which found a much higher discontinuation rate with the infliximab biosimilar compared with originator product in patients with rheumatoid arthritis.

The authors correctly note that the vast majority of the studies reviewed involved a single biosimilar switch, and that multiple switches may result in additional safety signals. However, they also point out that “patients have already been exposed to de facto multiple switches for many originator biologics when product quality attributes changed after one or more manufacturing process modifications were introduced.”

The question arises as to whether multiple switch studies are truly necessary outside of the requirement to prove interchangeability between a biosimilar and a reference product. There is a practical reason for doing so—the possibility (actually, the likelihood) of a patient enrolling in a new health plan one year, which covers the biosimilar but not the reference product. If the patient’s health plan changes once again one or two years later, that person may well be required to switch back to the reference product or yet another biosimilar.

This will heighten the importance of collecting real-world evidence and accumulating more experience outside of the clinical trial environment in terms of switching. Efforts such as those at the Biologics and Biosimilars Collective Intelligence Consortium should fill this gap over the next several years.

 

What Will Be Considered a Biosimilar in 2020?

Payers, providers, and patients in the US are narrowly focused on a limited set of biosimilar products; we all know them well—the anti-TNFs, the colony-stimulating growth factors, and most recently some antitumor drugs (e.g., trastuzumab, rituximab, and bevacizumab). In 2020, before the first biosimilar to Humira® hits the market, some medications may be reclassified as biosimilar status.

Tucked away in the Biologics Price Competition and Innovation Act of 2009 (BPCIA) is a set of obscure provisions that has the potential to create a good deal of confusion at that time.

“Transition drugs.” If you’re familiar with the term, you’re one of the few. Some medications are “transitioning” in the next couple of years. Specifically, drugs that will be transitioned include the insulins, but also other naturally occurring proteins, such as hyaluronidase, human growth hormones, and menotropins.

The mechanism is actually quite simple. Today, these products are all approvable under the original Food, Drug, and Cosmetics (FD&C) Act of 1962. By 2020, these agents will be approvable as biologics under the BPCIA. That means that they will not only be categorized as a biologic, but they will be subject to biosimilar—not generic—competition. No more new drug applications or abbreviated new drug applications, only biologic license applications of the 351(a) and 351(k) varieties.

In March 2016, the Food and Drug Administration (FDA) issued draft guidance on these transitional producinsulin-pensts. As the Regulatory Affairs Professional Society described it earlier this year, “Put simply: FDA will not approve any pending or tentatively approved application for a biological product under the Federal [FD&C] Act after 23 March 2020.”

This may have the effect of slowing approval of today’s so-called follow-on biologics, which will have to go through the 351(k) application process. For example, Lilly received approval for its insulin glargine product under a 505(b)2 application. This application process allowed Lilly to use clinical data from Sanofi’s originator product Lantus®. Under the letter of the new law, because no insulin glargine product has been approved via the biologic license application route, there are no “reference” or originator insulin products.

This can result in labeling and exclusivity period issues as well, possibly discouraging manufacturers of these products from applying for FDA approval. “Nothing in the [BPCIA] suggests that Congress intended to grant biological products approved under section 505 of the FD&C Act—some of which were approved decades ago—a period of exclusivity upon being deemed to have a license under the PHS Act that would impede biosimilar or interchangeable product competition in several product classes until the year 2032,” FDA said.

A legislative proposal was introduced in 2015 by Representative Michael Burgess (R-TX), which would have asked the Government Accountability Office to review the provisions and their potential impact before the 2020 transition took place. The proposal did not advance in the House.

A search revealed no updates on the legislative or regulatory sides of the fence, so we assume the transition will occur as intended. Currently stated policy by the FDA is that all biologics will receive a new four-character suffix to their nonproprietary names. Will this apply to the older insulins and growth hormones as well? Will coding, descriptors, or nomenclature for Lantus® have to change to reflect a new status as a reference biologic product? Or will this only apply to medications approved after March 2020 (in which case, there could be a confusing dichotomy here).

It could get a bit messy, folks.