In the pharmaceutical industry, patentees occasionally find new uses for patented drugs. In those cases, courts have long held that they can obtain new patents on subsets of their old patents – called “selection patents” – if those subsets have “special advantages” not disclosed in the old patents.
But what happens if the patentee doesn’t find a new use, but finds that a subset is more effective for its original uses? In Pharmascience Inc v Bristol-Myers Squibb Canada Co, 2022 FCA 142, the Federal Court of Appeal (“FCA”) found a selection patent valid in precisely that case, among other interesting conclusions.
Facts and Arguments
In Pharmasience, the plaintiffs (respondents on appeal), Bristol-Myers Squibb Canada Co., Bristol-Myers Squibb Holdings Ireland Unlimited Company and Pfizer Inc. (collectively “BMS”), initially held patent No. 2,349,330 (the “Genus Patent”). The Genus Patent disclosed a large number of FXa inhibitors to treat thrombosis, including apixaban. Two years later, the BMS filed an application for patent No. 2,461,202 (the “Selection Patent”). The Selection Patent initially disclosed a subset of the drugs disclosed in the Genus Patent as more effective treatments for thrombosis, without singling out apixaban. Between filing and issuance, it was narrowed to only include apixaban, highlighting it as especially effective.
BMS sued Pharmascience Inc. (“PMS”) and Sandoz Canada Inc. (“Sandoz”) for breach of the Selection Patent and another patent.
PMS and Sandoz challenged the validity of the Selection Patent on seven bases, three of which led to important results on appeal. Those arguments were:
- Anticipation & Obviousness: The Genus Patent anticipated the Selection Patent, and the Selection Patent was obvious in light of the Genus Patent; and
- Insufficiency: At the time of filing, the disclosure for the Selection Patent was insufficient because it did not explicitly reference a special advantage.
The trial judge rejected these arguments and found PMS and Sandoz liable for patent infringement. Both PMS and Sandoz appealed. Shortly before the hearing of the appeal, Sandoz filed a notice discontinuance. On appeal, PMS also argued:
- Misunderstanding of the Patent: The trial judge failed to assess whether the Selection Patent was a selection patent, suggesting that he misunderstood the nature of that patent.
The FCA agreed with the trial judge’s decision, dismissing the appeal for reasons discussed below.