On Apr. 05, 2024, Federal Circuit vacated PTAB’s decision in an IPR and remanded the case for the PTAB to dismiss the  proceedings as the case got moot.

Sumitomo Pharma Co., Ltd. owned a patent (U.S. Patent No. 9,815,827) titled “Agent for Treatment of Schizophrenia,” which detailed dosing regimens for treating certain psychotic disorders with lurasidone, a pharmaceutical compound. The patent specifically claimed dosing regimens that treated schizophrenia without causing clinically significant weight gain, a common adverse side effect of many antipsychotic drugs. Slayback Pharma LLC petitioned for an inter partes review (IPR) of the patent, and the Patent Trial and Appeal Board (PTAB) held all claims of the patent to be unpatentable for obviousness over a prior-art reference. The PTAB’s decision was based on its finding that the prior art sufficiently taught or suggested the use of lurasidone at the claimed dosages and frequencies for treating psychotic disorders. While the prior art did not expressly disclose the absence-of-weight-gain property claimed in the patent, the PTAB inferred it to be inherent in the claimed method of treatment.

Sumitomo appealed the PTAB’s decision, arguing that the PTAB did not properly consider certain evidence and made errors in its application of the law regarding obviousness. However, just before oral argument, the patent in question expired. Sumitomo indicated during oral argument that it lacked a concrete interest in the outcome of the litigation, as it did not seek damages for pre-expiration infringement of the patent. Sumitomo expressed no interest in pursuing damages from potential infringers who used the claimed methods before the patent’s expiration.

In light of Sumitomo’s lack of a legally cognizable interest in the validity of the patent post-expiration, the court found the case to be moot. Consequently, the court vacated the PTAB’s decision and remanded the case for the PTAB to dismiss the IPR proceedings.

“CAFC opinion”