Registered marks, generic prefixes, and medicinal product similarity shape infringement and passing off analysis in interim relief disputes.

A registered proprietor cannot ordinarily sustain an infringement claim against another registered proprietor of an identical or similar mark while both registrations subsist, and pending rectification proceedings do not automatically suspend the registered rights. In a passing off dispute over medicinal products, the common prefix drawn from a generic name was not treated as monopolisable, while differences in suffix, packaging, presentation, shelf life and price were relevant to deceptive similarity. The analysis also emphasises balance of convenience and public interest in medicines, with restraint being less likely where continued sale of the defendant's product would cause greater prejudice than allowing the market presence to continue.

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Issues: (i) Whether the plaintiffs could maintain an infringement claim and resist the defendant's registered mark in view of the defendant's registration and the provisions governing registration, rights of registered proprietors, and rectification proceedings; (ii) Whether the plaintiffs were entitled to continue the interim injunction on a passing off claim on the ground that the marks were deceptively similar, despite both parties using the same drug and a common prefix derived from the generic name.

Issue (i): Whether the plaintiffs could maintain an infringement claim and resist the defendant's registered mark in view of the defendant's registration and the provisions governing registration, rights of registered proprietors, and rectification proceedings.

Analysis: The defendant's mark was treated as registered from the date of the application. Once both marks stood registered, the statutory scheme did not permit one registered proprietor to claim exclusive infringement relief against another registered proprietor of an identical or nearly similar mark. The pending rectification proceedings did not, by themselves, suspend the defendant's registered rights, and the plaintiffs could not bypass the prima facie requirement contemplated for rectification-related proceedings.

Conclusion: The infringement-based challenge failed, and the plaintiffs could not sustain interim protection on that footing.

Issue (ii): Whether the plaintiffs were entitled to continue the interim injunction on a passing off claim on the ground that the marks were deceptively similar, despite both parties using the same drug and a common prefix derived from the generic name.

Analysis: The competing products were the same medicine, with similar composition and only limited differences in shelf life, packaging details, and price. The common prefix was treated as derived from the generic name and not capable of monopoly, while the distinguishing suffixes, appearance, and presentation were found materially different. In the context of medicinal products, the Court applied the balance of convenience and public interest, and found that the defendant's continued sale at a lower price would be more prejudiced by restraint than the plaintiffs would be by allowing the product to remain in the market. The apprehended confusion was not considered sufficient to justify continuation of the injunction.

Conclusion: The passing off claim did not justify continuation of the interim restraint, and the injunction was vacated.

Final Conclusion: The plaintiffs' interim relief failed on both infringement and passing off grounds, the defendant's application succeeded, and the earlier restraint order was set aside.

Ratio Decidendi: A registered proprietor cannot maintain infringement relief against another registered proprietor of a similar mark, and where the competing medicinal products are the same drug with a common generic prefix but materially distinct suffixes and presentation, interim restraint will not follow unless deceptive similarity and balance of convenience clearly justify it.

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