Call for Public Comments on Medical Use Inventions and the Scope of Effect of Patent Term Extended Patents

The Osaka District Court Decision of March 3, 2026, Reiwa 7 (Wa) Nos. 10786 and 10790, an action seeking an injunction for infringement, concerned two medical use inventions relating to the originator drug AMITIZA Capsules 24 μg/12 μg, containing lubiprostone as the active ingredient. The plaintiffs sought an injunction against the generic drug SAWAI Lubiprostone Capsules 24 μg. Although the court found that the defendant’s product itself fell within the technical scope of the inventions, it held that the effect of the patent term extensions concerning the 12 μg formulation (Extensions 1-2 and 2-2) did not reach the 24 μg formulation and dismissedthe plaintiffs’ claims., Third-party public comments were solicited in the appeal, IP High Court Reiwa 8 (Ne) No. 10041, concerning how to determine the technical scope of medical use inventions and the scope of effect of patent term extended patents. This article outlines the Osaka District Court decision, the public-comment topics, and issues concerning medical use inventions and the patent term extension system.