A Rare Inter Partes Review for an Orange Book Listed Patent

Ranbaxy Laboratories, Ltd. (“Ranbaxy”) and Vertex Pharmaceutical, Inc. (“Vertex”) recently settled an inter partes review (“IPR”) proceeding regarding Vertex’s U.S. Patent No. 6,436,989 (“the ‘989 Patent”). Vertex had listed the ‘989 Patent in the FDA’s published Approved Drug Products with Therapeutic Equivalence Evaluations, otherwise known as the Orange Book, as covering its HIV drug, Lexiva®. The significance of this event is the rarity of the use of IPR on patents typically challenged under the Hatch-Waxman framework. Recent statistics show that the majority of IPR have involved electrical/computer patents. Less than 6% of IPRs have been directed to biotechnology/pharmaceutical patents. The likely reason for the limited use of IPR on pharmaceutical patents, particularly those listed in the Orange Book, is the estoppel provisions of the IPR proceedings. See 35 U.S.C. §§ 315(e).

Following an IPR proceeding, the petitioner may not assert in a subsequent or concurrent district court or ITC action that a claim is invalid on any ground that the petitioner raised or reasonably could have raised in the inter partes review. Thus, in most cases, an ANDA filer would likely be barred from raising any defense that the Orange Book listed patent is invalid in any subsequent or concurrent Hatch-Waxman litigation.

In the case of Ranbaxy, it is not clear why Ranbaxy was not a named-party in a Hatch-Waxman litigation. Vertex asserted the ‘989 Patent against Mylan Inc. and Mylan Pharmaceuticals Inc. (“Mylan”) in the District of Delaware on August 22, 2012 (Civ. No. 12-1065-RGA). Ranbaxy was not a named defendant in that, or any other litigation. It is possible that Ranbaxy did not file a paragraph IV certification or Vertex chose not to file suit.

Nonetheless, on October 18, 2012, shortly after Vertex had asserted the ‘989 patent against Mylan, Ranbaxy filed its petition at the United States Patent and Trademark Office challenging all of the ‘989 patent claims. On March 5, 2013, the Patent Trial and Appeal Board found that Ranbaxy had demonstrated a reasonable likelihood that it would prevail, and thus instituted the IPR. On October 31, 2013, Vertex and Ranbaxy filed a joint motion to terminate the IPR. The parties’ motion not only resolved the IPR, but also stated that the parties had resolved “any potential Hatch-Waxman litigation on [the ‘989 Patent] between these parties.”

Given the limited precedent on this issue, Gibbons will continue to track future developments (if any) stemming from this case.