Eisai Co. Ltd. & Anr. v. Satish Reddy & Anr.

The plaintiffs instituted an infringement suit seeking an interim injunction against the defendants to prevent them from launching an anti-obesity drug covering the patented molecule Lorcaserin and its salts. In response, the defendants argued that their salt form was excluded from the suit patent, asserted that the patent was invalid, and highlighted that the plaintiffs had not worked the invention in India. The court rejected these defenses at the interlocutory stage, finding that the broad genus patent covered the contested salt form and that non-working should be addressed via compulsory licensing rather than unauthorized manufacture. Additionally, the court underscored that the defendants failed to seek revocation or clear the way before securing commercial permissions despite acknowledging the plaintiffs' patent. Consequently, the court granted an interim injunction restraining the defendants from manufacturing or distributing the infringing pharmaceutical product pending final disposal of the suit. Result: Plaintiffs' application for interim injunction allowed; defendants restrained from manufacturing, marketing, or offering for sale the patented drug pending trial.