The Code is Cracked: Interchangeable Biologics are Here

August 13, 2021By Sara W. Koblitz

About two weeks ago, FDA made an exciting announcement (and it remains exciting even if we’re late posting about it): FDA approved the first interchangeable biosimilar.  On July 30, 2021, FDA approved Semglee (insulin glargine-yfgn), an insulin product that relies on Lantus (insulin glargine) as its reference product.  In its Press Release, FDA explains that Mylan, the Semglee sponsor, submitted evidence that showed that “there are no clinically meaningful differences” between Semglee and Lantus “in terms of safety, purity, and potency (safety and effectiveness)” and that Semglee “can be expected to produce the same clinical result as Lantus” in any given patient.  As a result of this decision, Semglee can now be substituted for Lantus prescriptions without the intervention of a health care provider in accordance with state substitution regulations.  While Semglee was previously approved as a 505(b)(2) NDA referencing Lantus in June 2020, it was not rated as therapeutically equivalent (and therefore substitutable) to Lantus, and it immediately transitioned to a BLA upon approval as a result of the BPCIA (more on that below).  Thus, though Semglee is not new to the market, it is for the first time substitutable for Lantus without intervention of a health care provider.

Though Congress enacted the pathway for approval of interchangeable biosimilars in 2010 in an effort to incentivize competition to address the high prices of biologics, no sponsor had yet to crack the code to interchangeable approval until now.  In the past eleven years, we have seen a plethora of biosimilar approvals—which, like their name implies, are “similar” but not quite the “same” as and therefore substitutable for approved biologics—but substitutable biologics remained a pipe dream due to the difficulty of replicating a large molecule.  Biosimilars do provide a more affordable way for sponsors to get products onto the market—by referencing the clinical studies performed by the reference product sponsor—which, in theory, allows for the introduction of lower cost versions of expensive biologics.  But because these biosimilars cannot be substituted for their reference products—requiring health care professional brand awareness for both the brand name and the biosimilar—biosimilars have not quite made the dent in the market that Congress had hoped.  The expectation is that interchangeable biologics would make all the difference.

Yet, even with the first interchangeable biosimilar approval, it’s not quite clear when patients will see those savings.  Though no exclusivity is listed in the Purple Book yet, Semglee should be eligible for 12 months of exclusivity, which would block FDA licensure of any subsequent interchangeable biosimilars starting from its first commercial launch.  Even though Semglee has been approved and marketed as a biologic for a little over a year already and therefore first commercial marketing already has occurred, it’s interchangeable biosimilar is approved under a new BLA.  Interchangeable exclusivity, assuming it’s awarded, likely will be triggered at launch of the product under the new BLA, which, according to the NDC Code database, has not yet occurred.

Regardless of exclusivity, with no interchangeable competition as of yet, Mylan can price Semglee only slightly less than Lantus and still take market share, only marginally reducing costs to consumers.  As FDA states in its Press Release, “Biosimilars marketed in the U.S. typically have launched with initial list prices 15% to 35% lower than comparative list prices of the reference products,” but this 15 to 35% is not a huge relief for patients given the high cost of biologics.  For that reason, FDA merely states that biosimilars have the “potential to reduce health care costs.”  It’s not clear how much interchangeable approval will affect these health care cost reductions or how much competition is needed for prices to come down.  So, it remains to be seen if and when interchangeable Semglee will have any meaningful effect on insulin prices in the near future.

And it’s no surprise that the first interchangeable biosimilar is insulin.  FDA has long encouraged generic competition for insulin but developing a generic under an ANDA was very difficult “due to the complexities of these products”.  As part of the BPCIA, Congress amended the definition of “biologic” so that it included proteins, and protein products previously approved as drugs transitioned to biologics in March 2020, and, also under the BPCIA, became eligible for use as a reference product for biosimilar approval.  This transition eased the way for the development of insulin follow-on products because they no longer needed to be identical to their reference products for generic approval.  In 2019, Commissioner Gottlieb even noted: “The transition is particularly important for insulin” and that “FDA is dedicated to facilitating access to insulin.”  FDA further held a public hearing specific to insulin interchangeable biosimilar, and, in November 2019, issued a guidance on clinical immunogenicity specifically for insulin products.  To say that access to lower cost insulin products has been a priority for the Agency may be an understatement.

In tandem with its approval of Semglee, FDA issued a Consumer Update, as well as Fact Sheets and Stakeholder Toolkits, explaining the “treatment choices” arising from biosimilar and interchangeable approvals.  In contrast to claims made by certain reference product sponsors (which Pfizer took issue with back in 2018), FDA states in the Update that “Biosimilars are as safe and effective as the original biologic” and that consumers “can expect the same safety and effectiveness from the biosimilar over the course of treatment as you would from the original product.”  An interchangeable “meets additional requirements” for substitution, and “health care providers and patients can be confident in the safety and effectiveness of a biosimilar or an interchangeable biosimilar product, just as they would be for the FDA-approved original product.”  Even before this approval and Update, health insurers heard this message loud and clear and have taken to paying patients to switch to biosimilar versions of medications to encourage widespread use in an effort to address costs.

FDA, in its Consumer Updates, states that it “expects to approve more interchangeable products in the future.”  Now that FDA has hit this milestone and mapped a blueprint for its interchangeable expectations, hopefully we won’t have to wait too much longer for the flurry of interchangeable approvals needed to add some meaningful competition in the biologics market and presumably address biologic prices.