Canada’s Intellectual Property Firm

Janssen’s abiraterone acetate and prednisone combination therapy patent found invalid

Authored byChen Li

Update: On November 1, 2022, the Federal Court of Appeal upheld the trial judge’s decision: Janssen Inc v Apotex Inc, 2022 FCA 184.


On January 14, 2020, the Federal Court released a decision by Phelan J. in patent infringement actions pursuant to subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations (PMNOC Regulations) relating to the drug abiraterone acetate (Janssen’s ZYTIGA). The Court found Canadian Patent No. 2,661,422 (the 422 patent) invalid on the basis of obviousness and dismissed the Plaintiffs’ actions against Apotex, Dr. Reddy’s Laboratories, and Pharmascience: Janssen Inc v Apotex Inc, 2021 FC 7.

As reported earlier, Phelan J. previously granted an order prohibiting the Minister of Health from issuing a Notice of Compliance (NOC) to Apotex for a generic version of ZYTIGA in the last decision under the pre-amended PMNOC Regulations. However, estoppel was not raised and both the Court and the parties treated the matter as a new proceeding.

The 422 patent generally claims the use of the combination of abiraterone acetate and prednisone for the treatment of prostate cancer. The Court found that abiraterone acetate was known to effectively treat prostate cancer; prednisone was known to effectively treat prostate cancer; and the state of the art taught combination of drugs like abiraterone acetate and prednisone.  Further, the common general knowledge and the state of the art at the relevant time suggested that the combination had a reasonable probability of success in treating prostate cancer. Accordingly, the 422 patent was found invalid for obviousness. The Court rejected the Defendants’ validity challenges based on lack of demonstrated utility, insufficiency, and unpatentable subject matter. Had the 422 patent been found valid, the Court would have found that the Defendants would induce infringement of the Asserted Claims based on the product monographs.

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