PTAB Denies Priority Claim, Has No Affinity For "Antibody Rule"

Addressing enablement and written description issues in the context of a priority challenge, the Patent Trial and Appeal Board (PTAB or Board) found that the challenged claims were not entitled to the benefit of the parent application and thus were anticipated by an intervening reference. Daiichi Sankyo Company, Ltd. v. Alethia Biotherapeutics, Inc., Case No. IPR2015-00291 (PTAB, June 14, 2016) (Snedden, APJ).

The challenged patent’s claims are directed to a method of impairing osteoclast differentiation that includes administering to a subject an antibody or antigen binding fragment that specifically binds to human or murine Siglec-15. The challenged patent is a continuation in part of an earlier-filed patent. The petitioner challenged certain claims as anticipated by a single prior art reference. The patent owner did not dispute that the prior art reference disclosed the limitations of the claims, instead challenging only the availability of the reference as