As of July 2017 there had been at least 363 inter partes review petitions filed against patents listed in the Food and Drug Administration's Orange Book and 74 filed against patents that have been identified as reading on Purple Book Centre for Drug Evaluation and Research-listed biologic drugs. Of these 437 inter partes reviews, 116 resulted in a final written decision. There are a number of lessons to be learned from these.
There has been some concern regarding the statistics periodically issued by the US Patent Trial and Appeal Board, owing to the fact that the reported numbers overlook multiple inter partes review challenges to the same patents and, potentially, different outcomes in those challenges. While certain drug patents have been challenged in multiple inter partes review petitions, concern as to different outcomes appears to be unfounded.
The US Patent Trial and Appeal Board (PTAB) recently released updated statistics showing the fate of resolved inter partes review proceedings. These statistics show that a total of 4,563 inter partes review petitions were resolved as of March 31 2017, including 1,577 final written decisions. In 81% of these final written decisions, at least some instituted patent claims were found unpatentable. This statistic has contributed to concerns that the PTAB is a patent 'death squad'.
In a turning point for the emerging US biosimilars market, the US Food and Drug Administration approved Sandoz's application to market Zarxio, the first biosimilar drug in the United States. IP owners in the biologics industry should begin identifying relevant patents and conducting due diligence to prepare not only for patent litigation, but also potentially for inter partes review proceedings.