On April 2, 2019, Eli Lilly and Company (“Lilly”) filed a Petition for Post-Grant Review (“PGR”) of Genentech’s U.S. Patent 10,011,654 (“the ’654 patent”). The ’654 patent, entitled “Antibodies Directed to IL-17A/IL-17F Heterodimers,” has just seven claims, with independent claim 1 drawn to “[a]n isolated humanized monoclonal antibody that binds to an IL-17A-17F heterodimer comprising the polypeptide of SEQ ID NO: 3 and the polypeptide of SEQ ID NO: 4 with or without their associated signal peptides.” The ’654 patent was issued on July 3, 2018, and within minutes of the issuance, Genentech filed suit against Lilly in the Southern District of California alleging infringement of the ’654 patent by Lilly’s Taltz® (containing ixekizumab as its active ingredient).[1] The case, captioned Genentech, Inc. v. Eli Lilly and Company, Case No. 18-cv-1518, is currently in the discovery stage. The PGR petition is timely filed within one year of that complaint and within nine months of the grant date of the patent.

Lilly’s PGR petition alleges that it is more likely than not that all seven claims of the ’654 patent are unpatentable on the following grounds: (1) claims 1-7 lack written description support under 35 U.S.C. § 112(a); (2) claims 1-7 lack enablement under 35 U.S.C. § 112(a); (3) claims 1-7 are anticipated under 35 U.S.C. § 102(a) by U.S. Publication No. 2010/0266609A1 to Adams et al.; and (4) claims 1-7 are anticipated under 35 U.S.C. § 102(a) by U.S. Publication No. 2013/0315911A1 to Stevens et al. Specifically, Lilly alleges that Genentech’s ’654 patent claims a genus of antibodies defined solely by function- the ability to bind to a particular protein: IL-17A/F. Lilly asserts that this functional characterization, without more, is insufficient to establish written description support for a claimed functional genus. According to Lilly, the appropriate tests for written description support are those set forth by the Federal Circuit in Amgen Inc. v. Sanofi [2] and Ariad Pharm., Inc. v. Eli Lilly & Co.[3], which the USPTO has expressly endorsed in recent guidance to examiners, but which was not available during prosecution of the ’654 patent. Because the ’654 patent – and its asserted priority applications – allegedly fail to disclose a representative number of antibodies falling within the scope of the claimed genus or any structural features common to the members of the genus such that one of skill in the art could visualize or recognize the members of that genus, Lilly asserts that the ’654 patent fails these tests and therefore does not meet the written description requirement. In a similar vein, the PGR petition further alleges that the specification of the ’654 patent (and its priority applications) does not enable those skilled in the art to make and use whole categories of antibodies falling within the claims, without undue experimentation.

Lilly also notes that European Patent No. 1641822B1 (“EP ‘822”), the European counterpart to the ’654 patent and claiming priority to the same U.S. provisional applications, was revoked in its entirety by the EPO on November 24, 2016, on added matter grounds after an opposition proceeding. The High Court of Justice in the U.K., according to Lilly, found the U.K. counterpart to be invalid as well, finding that the claims to the antibody and its uses in treating rheumatoid arthritis were obvious and that the claims directed to the use of the antibodies that bind to IL-17A/F to treat psoriasis were invalid on insufficiency grounds.

Interestingly, Lilly’s petition for PGR comes hot on the heels of another Petition for Post-Grant Review of the ’654 patent filed just a day before, on April 1, 2019, by UCB, Inc. (“UCB”). As in Lilly’s petition, UCB’s petition also alleges that claims 1-7 of the ’654 patent are unpatentable for a lack of written description, with UCB specifically asserting that the ’654 patent does not adequately describe a genus of anti-IL-17A/F humanized antibodies and does not disclose a representative number of species or common structural features, as required by the Federal Circuit case law.

Under 37 C.F.R. § 42.207, if patent owner Genentech wishes to file a preliminary response to the petitions, it must do so no later than three months after the date of the USPTO’s notice according a filing date to the petitions. The PTAB must then determine whether to institute a trial within three months of the earlier of (1) the patent owner’s preliminary response filing and (2) the preliminary response due date.[4]