In IPR2015-01537, Momenta petitioned for IPR of claims 1-15 of U.S. Patent No. 8,476,239 owned by Bristol-Myers Squibb (BMS) on grounds of obviousness over three references: Cohen, Shire, and Carpenter.  Petitioner also relied on expert testimony.  The claims recite formulations containing CTLA4Ig, which is a stabilized form of a negative regulator (checkpoint inhibitor) of the immune system useful in treating autoimmune disease and rheumatoid arthritis, for example.  The Patent Owner opposed institution by attacking the Petitioner’s position as failing to provide a reason to combine the cited references and as relying on impermissible hindsight in arriving at a formulation that satisfied all features recited in the claims (i.e., tonicity, pH, excipient concentration, excipient:therapeutic mass ratio, volume, and stability).  The Board relied on KSR Int’l Co. v. Teleflex Inc. for principles underlying the obviousness inquiry, including reliance on general disclosures encompassing specific claim-recited features, on knowledge in the art, on common sense, and on recognition that persons of ordinary skill had ordinary creativity.  The Board also credited Petitioner’s expert witness testimony.  Finding that the Patent Owner’s opposition did not argue  that CTLA4Ig was a protein possessing unique characteristics that would have required specific formulations to be effective, the Board concluded that there was a reasonable likelihood that at least one of claims 1-15 would be obvious under 35 U.S.C. § 103(a) over Cohen, Shire, and Carpenter.

In asserting that the claims were obvious, Petitioner relied on Cohen as teaching that CTLA4Ig was known to be useful in treating rheumatoid arthritis, an autoimmune disorder, that Shire taught that subcutaneous administration was useful for the chronic administration of a therapeutic, in part because of its relative ease of use that promoted patient compliance, and that Carpenter established that one of ordinary skill would consider the various properties, or “constraints,” recited in the claims (see above).  In support of these assertions, Petitioner provided expert testimony to walk the Board through its consideration of the various claim limitations drawn to particular properties or “constraints.”  For example, the Board relied on expert testimony in considering the different therapeutic concentrations recited in the references and in the claims, and in establishing that the claim-recited excipient:therapeutic ratio was known in the art.

The Board found BMS’s argument that there was no disclosure or suggestion of the specific properties recited in the claims unpersuasive because KSR established that a precise teaching in the prior art of specific claimed subject matter is not required.  The Board relied on the teachings of interrelated patents, design demands in the field, and the background knowledge of those of ordinary skill to find a reason to combine the teachings in the cited art.  With respect to claim-recited properties not addressed in even a general sense in those references, the Board found that those of ordinary skill were aware of such properties and would routinely optimize them in developing therapeutic formulations for subcutaneous administration.  The Board further disagreed with the Patent Owner’s argument that the obviousness argument was based on impermissible hindsight reconstruction, asserting that all of the claim-recited properties were known in the art as relevant to therapeutic formulations and, thus, were not identified through impermissible hindsight.  Beyond these considerations, the Board emphasized that, at this stage in the development of the record, the Patent Owner had not submitted any documentary evidence or expert testimony, including any evidence of secondary considerations, in support of its position that the granted claims were non-obvious over the cited art.  This evidence and testimony may be expected during the trial.

Patent Owner does not argue or present evidence that CTLA4Ig has unique characteristics requiring a specific formulation or that secondary considerations, such as unexpected results, indicate the claimed formulations would not have been obvious.

As a result of the analysis summarized above, the Board concluded that there is a reasonable likelihood that at least one challenged claim is obvious, and instituted a trial.  While a final written decision has not yet been reached in this matter, the apparent lessons from the institution decision are that claims drawn to formulations of therapeutics not shown to exhibit unique characteristics could be vulnerable to obviousness attacks in IPRs and, if such claims are challenged in an IPR petition, serious consideration should be given to submission of documentary evidence and expert testimony (now permitted under revised PTAB rules, as previously reported) in support of a preliminary response to the petition. Further, the Board here offered a roadmap of the type of evidence and argument that a Patent Owner may present during the trial that ultimately may lead to the Patent Owner’s success in a final written decision. Thus, while the Patent Owner may not welcome a decision instituting an AIA trial, the Patent Owner may use the analysis in the decision to directly address the Board’s concerns in a way that may lead it to success and, in turn, estop the Petitioner from ever challenging validity on printed prior art grounds.