Atazanavir - Canada

On Apr 11, 2017, the Federal Court of Appeal delivered its decision in BMS. v. Teva case regarding drug Atazanavir.

In 1998, BristolMyers Squibb Canada Co. (BMS), having acquired rights to the atazanavir molecule, filed a patent application for Type-I atazanavir bisulfate, a salt of atazanavir whose superior bioavailability makes it useful in the formulation of an oral dosage of atazanavir. BMS obtained Canadian Letters Patent No. 2,317,736 (the ‘736 patent) in 2004.

In proceedings under the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133, the Federal Court found that Teva Canada Limited’s (Teva) allegation that the ‘736 patent was invalid for obviousness was justified and dismissed BMS’ application for a writ of prohibition. This is an appeal from that decision.

BMS argues that the Federal Court erred in its application of the “obvious to try” test and in concluding that Teva’s allegation of obviousness was justified in spite of the fact that it found that some of the properties of Type-I atazanavir bisulfate were not predictable before it was made and tested.

In dismissing BMS' appeal, the Court of Appeal held that a categorical approach to obviousness, such as that advocated by BMS, is inappropriate. The elaboration of a hard and fast rule that obviousness cannot be shown unless all the elements of the inventive concept can be predicted with a high degree of certainty is the antithesis of the approach to obviousness that the Supreme Court favored in Plavix 1. Not every case requires recourse to the “obvious to try” test and not every recourse to the “obvious to try” test must follow in the furrow of the preceding application of that test.

Court of Appeal further concluded that the Applications Judge had not erred in the application of the "obvious to try" test, but had erred by finding that the anhydrous nature and physical stability of the salt formed part of the inventive concept of the 736 Patent. This error, however, did not lead the Court of Appeal to overturn the judgment.