Battles over Biosimilars - Pharmaceutical Executive


Battles over Biosimilars

Pharmaceutical Executive

Interchangeability and Exclusivity

Equally challenging for FDA is to define interchangeability testing requirements and whether clinical switching studies will be required to meet that standard. An interchangeable designation is important because the first follow-on biologic so deemed by FDA enjoys a year of market exclusivity, during which FDA may not approve another similar interchangeable product.

Biosimilar makers note that switching studies are not required for innovator manufacturers to document comparability following post-approval changes. Yet, innovators maintain that clinical studies in multiple populations are necessary to ensure safety and efficacy with product switching. Amgen vice president Anthony Mire-Sluis pointed out that head-to-head studies are needed to compare immunogenicity between reference and follow-on products, and that product labels should explicitly state approved indications and whether the biosimilar is interchangeable for that indication.

Although the BPCI authorized 12 years' exclusivity for innovator biologics, that has not ended the exclusivity debate. In addition to the 12 years when FDA cannot approve another product based on innovator data, biosimilars sponsors have to wait four years after BLA licensing to even submit a 351(k) application. Innovators claim these protections are needed to spur investment in R&D, but critics claim that 12 years is too long. The Obama administration recently proposed reducing exclusivity to seven years, largely to cut spending, but also to prevent patent "evergreening." Biosimilars makers fear that innovators will seek to extend protections by modifying a reference product's safety, purity, or potency sufficiently to make it "new." The change has to be significant, says Kozlowski of CDER: "I don't think that 'slightly better purity' is enough to extend exclusivity," he observed at the DIA/FDLI conference.

As with conventional generics, everyone is bracing for extensive legal maneuvering over patent and exclusivity issues. The BPCIA took FDA out of the patent-listing arena, but set up an even more complex process for dealing with patent disputes: Biosimilars makers have to provide the reference product sponsor with a full dossier on its process and product so that the innovator can determine which patents it feels may be infringed. This "hokey-pokey process," explained Sidley Austin attorney Jeffrey Kushan, was designed to promote early agreement on which patents are worth fighting about, but appears likely to create a highly competitive legal environment. Biosimilars makers fear that too many parties will gain access to their confidential filings, while BLA-holders stand to lose protection if they miss a deadline.

If the biosimilars regulatory process appears too complex and costly, it may limit the value of the 351(k) procedure and make the traditional BLA route to market—and its 12 years' exclusivity—the more attractive option for copycat biotech developers.

Jill Wechsler is Pharmaceutical Executive's Washington correspondent. She can be reached at


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