On April 5, 2016, the FDA approved Celltrion's application to market a biosimilar to Janssen Biotech Inc.'s REMICADE^® (infliximab) anti-TNF-α antibody (see "FDA Approves Inflectra - Celltrion's REMICADE® Biosimilar").  Presumably because of the Notice-of-Commercial-Marketing provision, Celltrion notified Janssen at the time that it would not begin selling its biosimilar drug product until at least October 2, 2016, subject to certain reservations (see "An Inflectra Update: Janssen Requests an Expedited Trial").  Fast forward to this Monday, October 17, 2016, and Pfizer announced that it would begin shipping the Celltrion biosimilar, named INFLECTRA^® (infliximab-dyyb), in late November 2016.  Pfizer pointed out in its press release that it holds the exclusive commercialization rights to INFLECTRA in the U.S., and that it has already introduced the biosimilar in other markets around the world.  This will be only the second biosimilar to be made available in the U.S., and the first biosimilar that is a therapeutic antibody.  Pfizer indicated that it intends to introduce INFLECTRA at a 15% discount to the current wholesaler acquisition cost (WAC) of REMICADE.

If Pfizer does indeed launch by the end of the year, it will most likely do so under a cloud of patent uncertainty.  On March 6, 2015, Janssen filed suit in the U.S. District Court for the District of Massachusetts against Celltrion Healthcare Co., Ltd., Celltrion, Inc., and Hospira, Inc, alleging infringement of six patents that purportedly covered the antibody at issue, methods of using the antibody, and methods and reagents for the manufacture of the antibody.  By the end of 2015, all counts related to three of the patents had been voluntarily dismissed.  Then, on March 22, 2016, Defendants stipulated that they would not begin selling their biosimilar drug product prior to June 30, 2016, the date on which a fourth patent expired.  As a result, when the FDA approved INFLECTRA, there were only two patents remaining in the lawsuit.

The first patent, U.S Patent No. 6,284,471, entitled "Anti-TNFa Antibodies and Assays Employing Anti-TNFa Antibodies," was invalidated by the Court on August 19, 2016 as a result of a Motion for Summary Judgement of Invalidity for Obviousness-Type Double Patenting filed by Celltrion.  The '471 patent issued on September 4, 2001, and because it was filed before the change in patent term that resulted from the Uruguay Round Agreements Act, it was set to expire 17 years after issuance, on September 4, 2018.  However, Janssen also held U.S. Patent 6,790,444, which issued on September 14, 2004 and expired on July 11, 2011 (because its expiration was based on priority date, not the issue date of the patent).  In reaching its decision, the Court noted that the Federal Circuit held in Gilead Sciences, Inc. v. Natco Pharma Ltd. "that a later-issuing, earlier-expiring patent can act as double-patenting reference for an earlier-issuing, later-expiring patent."  (We reported on the Gilead case at the time).  The District Court did acknowledge that the present case was distinct from Gilead because that case did not address the differences in patent term resulting from the Uruguay Round Agreements Act.  Nevertheless, it concluded that the Federal Circuit's reasoning in Gilead was equally applicable here, because "the statute was not intended to alter the judicial doctrine of obviousness double patenting."  Subsequently, on September 27, 2016, the District Court entered partial final judgement that the '471 patent is invalid so the issue could be appealed, because it reasoned that the decision was severable from the remaining issues and the Federal Circuit would not be required to decide the same issues more than once.  We will continue to cover this aspect of the case should it be appealed to the Federal Circuit.

The last remaining patent, U.S. Patent 7,598,083, is set to be tried to a jury in February, 2017.  Specifically, the Court has set the trial for the two weeks between February 13 and February 24.  The '083 patent is entitled "Chemically Defined Media Compositions," and is set to expire February 7, 2027.  Even though there is more than a decade of patent term remaining, Janssen informed the Court during a February 9, 2016 conference that it would not seek a preliminary injunction.  Correspondingly, Pfizer will not be prevented from launching at risk when it ships the biosimilar drug product at the end of the year.