Post-grant review (PGR) is potentially more powerful than IPR, as it allows challenges to any requirement of patentability, while IPR is limited to claim validity in view of patents and printed publications. Accordingly, PGR, if available, may in some cases be a better option for petitioners. In one recent case, PGR might have been the better option—had the petitioner persuaded the PTAB that the patent at issue qualified for PGR.
In the last two weeks, the PTAB has invalidated three patents covering Copaxone®, a multiple sclerosis drug marketed by Teva with annual sales of over $3 billion. Challenged by generic manufacturers Mylan and Amneal, the patents specifically covered a long-acting form of Copaxone®, known as “3-times-a-week COPAXONE® 40 mg/ml,” which Teva developed when the original version of Copaxone® was coming off patent protection.
These IPR decisions highlight the usefulness of post-grant proceedings for generic and biosimilar manufacturers, particularly for challenging follow-on patents, such as those covering specific dose regimens, as we discussed in earlier posts.
Despite black-letter law that IPRs can only resolve patentability based on prior art patents and printed publications, enablement and written description support can be key issues, particularly in life sciences patents with functional antibody claims. A final written decision in Daiichi Sankyo Company Limited v. Alethia Biotherapeutics, Inc. (IPR2015-00291) found such claims unpatentable after finding that the priority application failed to pass muster from a § 112 standpoint, but that the invention was disclosed in a reference published after the priority document was filed but before the filing of the continuation-in-part that was challenged.
Multiple IPRs challenging patents covering brand-name biologics have now been filed by biosimilar developers, for reasons we recently discussed, as well as by other entities. Institution decisions in these early IPRs and a small number of final written decisions suggest that broad mechanistic claims as well as follow-on patent claims—such as those covering methods of treating specific patient populations or specific dose regimens—will be vulnerable to obviousness challenges at the PTAB. However, a tougher time should be expected in challenging composition-of-matter patents.
Initially, biopharma represented a small percentage of post-grant proceedings; however, that percentage is increasing. In particular, generic and biosimilar manufacturers are recognizing advantages of this pathway. The high success rates achieved so far are compelling: For biopharma IPR petitions that have reached a final written decision, 66 percent have resulted in some or all of the challenged claims being invalidated.
The Cabilly patent family (including Cabilly I, II and III) is likely the most famous patent family in biotechnology. With claims that cover basic steps in generating therapeutic antibodies, these patents are gatekeepers in an industry that has shown unprecedented growth—currently, half of the 10 top-selling drugs in the world by sales are therapeutic antibodies. Through licensing to antibody manufacturers, Genentech—one of the owners of the Cabilly patents—is expected to reach a billion dollars in royalties from this patent family by 2018.