Federal Court opines on precedential value of prior PM(NOC) proceedings and scope of experimental use exception to public disclosure
The Federal Court’s decision in the consolidated proceedings of Bayer Inc. v Cobalt Pharmaceuticals Company offers useful guidance as to the precedential value of proceedings under the Patented Medicines (Notice of Compliance) Regulations (PM(NOC)) in the context of subsequent infringement actions involving the same patent. It also provides helpful direction in respect of the scope of the Canadian experimental use exception to anticipatory public disclosure.
Background: Patent at Issue
Both the PM(NOC) proceedings and the Federal Court infringement action concerned Bayer’s Canadian Patent No. 2,383,426 (the ‘426 Patent). The ‘426 Patent relates to a pharmaceutical combination of ethinylestradiol and drospirenone for their use as a contraceptive. Ethinylestradiol functions as an estrogen, and drospirenone as a progestogen, and both were known to inhibit ovulation when used in combination. The ‘426 Patent contemplated a novel formulation using rapidly-dissolving drospirenone particles, which delivered unexpectedly consistent bioavailability. This was unexpected because drospirenone was known to be inactive at an acidic pH of 1 when tested in a laboratory setting, and the normal pH range of the stomach is 1.0 to 3.0. However, traditional coatings that would protect the drospirenone from the stomach environment released the drospirenone at variable rates, resulting in irregular effectiveness in different people. Bayer tested a rapidly-dissolving particulate version of drospirenone in clinical trials with women, and discovered it was effective as a contraceptive in the ethinylestradiol combination, and did not degrade or require any coating. Bayer patented this formulation of the contraceptive in the ‘426 Patent, with an effective Canadian filing date of August 31, 2000, and currently markets two products known as “Yaz” and “Yasmin”, which incorporate the patented invention, with different doses of ethinylestradiol .Continue Reading...