Canada’s Intellectual Property Firm

Federal Court finds invalidity allegations relating to patent for metformin formulations not justified

On March 8, 2019, Justice Fothergill granted Valeant Canada’s application for an order prohibiting the Minister of Health from issuing a notice of compliance to Generic Partners for its generic version of Valeant’s GLUMETZA, a metformin formulation: Valeant Canada v Generic Partners Canada2019 FC 253.

Generic Partners had alleged that Patent No. 2,290,624, for controlled release dosage forms of drugs such as metformin, was invalid for anticipation, obviousness, double-patenting and insufficiency. The patent claims swellable dosage forms that include a size element (the lengths of the axes of the formulation), a time element (the time required to swell to the claimed size) and a shape element (an oval or parallelogram). When these elements are combined, they increase gastric retention of the dosage form.

With respect to anticipation and double-patenting, the Court found that the prior art document on which Generic Partners relied for both allegations did not disclose all three of the size, shape and time elements of the claimed formulations. With respect to obviousness, the Court found that although the size and time elements may have been disclosed, neither the shape element nor the combination of all three elements had been. Given that it was not known that dosage shapes would affect gastric retention, it could not be obvious to use an oval shape. With respect to insufficiency, the Court accepted Valeant’s evidence that any experimentation required to optimize the claimed dosage forms would be routine, and found the lack of data and examples in the patent irrelevant to sufficiency. 

Generic Partners may appeal as of right.

If you have any questions or would like further information, please contact a member of our firm’s Pharmaceutical and Life Sciences group.

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