Product Liability Update

The U.S. Food and Drug Administration announced on April 5 its second ever approval of a biosimilar  –  Inflectra (infliximab-dyyb) – for multiple indications. Inflectra was developed by Celltrion Inc. and licensed to Pfizer Inc., for treatment of rheumatoid arthritis, inflammatory bowel diseases and other conditions.  Inflectra is a biosimilar to Remicade which has been available since 1998 and had U.S. sales of $4.45 billion last year.

The Biologics Price Competition and Innovation Act of 2009 (BPCI Act) was passed as part of the Affordable Care Act that President Obama signed into law in March 2010. The BPCI Act created an abbreviated licensure pathway for biological products shown to be “biosimilar” to or “interchangeable” with an FDA-licensed biological product, called the “reference product.” This abbreviated licensure pathway under section 351(k) of the Public Health Service Act permits reliance on certain existing scientific knowledge about the safety and effectiveness of the reference product, and enables a biosimilar biological product to be licensed based on less than a full complement of product-specific preclinical and clinical data.

A biosimilar product is a biological product that is approved based on a showing that it is highly similar to an already-approved biological product, known as a reference product. The biosimilar also must show it has no clinically meaningful differences in terms of safety and effectiveness from the reference product. Only minor differences in clinically inactive components are allowable in biosimilar products .  According to the FDA’s Director of CDER, “[b]iosimilars can provide access to important treatment options for patients who need them,” and the community can be assured that the products meet the agency’s stringent scientific standards.

According to the FDA, its approval of Inflectra was based on a review of evidence that included structural and functional characterization, animal study data, human pharmacokinetic and pharmacodynamics data, clinical immunogenicity data and other clinical safety and effectiveness data that demonstrates Inflectra is biosimilar to Remicade.  Inflectra has been approved as biosimilar, not as an interchangeable product.  The approval of Inflectra comes a little over a year since the FDA approved its first biosimilar – Sandoz’ Zarxio, which is biosimilar to Amgen’s Neupogen.  Although plans for a 2016 launch of  Inflectra are supposedly underway, it is unclear when the product will actually hit the market as there is a pending patent infringement lawsuit in Massachusetts alleging that the product developed by Celltiron infringes on numerous Remicade patents.