Patent interim injunction refused where non-disclosure and weak pleadings undermined the claim against a phosphate variant product.

Interim injunction in a patent infringement suit was refused because the plaintiff did not adequately plead or establish, for interim relief, that the defendant's sitagliptin phosphate monohydrate product was only a trifling variation of the patented sitagliptin and lacked inventive significance. The court found the infringement case weakened by incomplete pleadings on efficacy, the role of phosphate, and equivalence. Relief was also declined because the plaintiffs had not candidly disclosed their failed and abandoned separate patent applications for sitagliptin phosphate, which contained admissions inconsistent with the suit. The defendant was therefore left unrestrained, subject to maintaining accounts of manufacture and sales pending trial.

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Issues: (i) whether interim injunction should be granted in a patent infringement action where the defendant's product contains sitagliptin phosphate monohydrate and the plaintiffs' patent is in sitagliptin; (ii) whether the plaintiffs' non-disclosure of their failed and abandoned patent applications for sitagliptin phosphate disentitled them to interim relief.

Issue (i): Whether interim injunction should be granted in a patent infringement action where the defendant's product contains sitagliptin phosphate monohydrate and the plaintiffs' patent is in sitagliptin.

Analysis: The decisive question was whether the addition of phosphate to the patented molecule amounted to a material variation taking the defendant's product outside the patent, or whether it was only a trifling and unessential change. The patent was understood as covering sitagliptin and its pharmaceutically acceptable salts, but the Court found that the plaintiffs had not pleaded or established, on the basis required for interim relief, that the defendant's formulation embodied no inventive advancement and achieved the same therapeutic result only by using the patented substance. The plaintiffs' case on infringement was also weakened by the absence of detailed pleadings on efficacy, the role of phosphate, and the alleged equivalence of the two products.

Conclusion: Interim injunction was not warranted on the infringement case made out by the plaintiffs.

Issue (ii): Whether the plaintiffs' non-disclosure of their failed and abandoned patent applications for sitagliptin phosphate disentitled them to interim relief.

Analysis: The Court treated the plaintiffs' own applications for a separate patent in sitagliptin phosphate, including their description of it as a new invention, as highly material. Those applications had been rejected or abandoned, yet the plaint did not candidly explain that position or the circumstances in which the separate patent claims had been made. The Court held that interim relief cannot be granted on a case not properly pleaded, particularly where the plaintiffs' own materials contained admissions inconsistent with the stand taken in the suit. The defendant's material also indicated that several others were marketing the same product, which further weakened the case for discretionary relief.

Conclusion: The plaintiffs were disentitled to interim relief because of non-disclosure and the absence of a properly pleaded case.

Final Conclusion: The application for interim injunction failed, and the defendant was left free from the restraint sought, though directed to maintain accounts of manufacture and sales pending the suit.

Ratio Decidendi: Interim injunction in a patent suit will be refused where the plaintiff has not pleaded and established that the alleged variant lacks inventive significance, and where material non-disclosure and inconsistent admissions undermine the entitlement to discretionary relief.

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