"Loophole" Tightens Around Double Patenting

Dan Whalen is a JD Candidate at Osgoode Hall Law School

Bayer was dealt a blow when the Federal Court of Appeal upheld the decision to deny the company a patent of a medical compound because it held a product-by-process patent for the substance already. In 1987, when the pharmaceutical giant received said rights, the Patent Act barred patents for medical compounds except when prepared by a described and claimed process. Following the repeal of this policy, effective 1991, Bayer applied for a direct patent. The Commissioner of Patents refused on the basis that the application involved no inventive ingenuity and thus was not sufficiently distinct from the earlier claim – a form of “obviousness” double patenting prohibited by the seminal Whirlpool Corp. v. Camco Inc. case.

In challenging the decision, Bayer analogized its situation to the circumstances of Aventis Pharma Inc. v. Mayne Pharma (Canada) Inc. The Federal Court ruled in that case that holding a previous patent for a product by a claimed process does not itself preclude a later patent for the same product for reasons of double patenting. Such a statement must exclude “same invention” double patenting, argued Bayer, thus it necessarily considered “obviousness” double patenting. This doctrine must thereby not apply in such cases, the company inferred. Further, the ruling was upheld by the Federal Court of Appeal in Pfizer Canada Inc. v. Canada (Minister of Health), rendering it authoritative.

In the case at bar, the Court held that closer inspection of Mayne reveals that it did not, in fact, create an exception for “obviousness” double patenting. If it did, the Court reasoned, such a ruling would be inconsistent with a core principle of patent legislation: bargain theory. By this view, a patent may be conceptualized as a bargain wherein the applicant is granted a time-limited monopoly of an invention, in exchange for full disclosure so the public may use it after the patent has expired. If the claimed invention is obvious, however, the public draws no benefit from its disclosure and granting the monopoly is unwarranted. Bayer may continue to fight this reasoning on further appeal, or simply concede that this supposed loophole for double patenting has finally closed in on them.