In January 2021, the Federal Court found Janssen's Canadian Patent No. 2,661,422 (the 422 patent) invalid on the basis of obviousness and dismissed its actions against Apotex, Dr. Reddy's Laboratories, and Pharmascience (for further details, see "Janssen's abiraterone acetate and prednisone combination therapy patent found invalid").

In a decision released on 1 November 2022, the Federal Court of Appeal dismissed Janssen's appeal on all issues.(1)


Trial judge's finding that abiraterone acetate was known to be prostate cancer treatment
The 422 patent concerns the treatment of prostate cancer in humans by co-administration of abiraterone acetate (AA) and prednisone (PN). The trial judge found, as part of the state of the art, that AA was known to treat prostate cancer. Janssen argued that this conclusion had been based on two erroneous findings – namely, that:

  • an admission in the 422 patent to this effect was binding on Janssen; and
  • the results of a study of AA as a treatment for prostate cancer (the 001 study) were reported in the prior art O'Donnell 2004 paper.

With respect to the first alleged error, Locke JA for the panel held that there was evidence on which the trial judge had been entitled to rely that supported the factual conclusion. He declined to decide whether, to what extent and under what circumstances an admission in a patent will be binding on the patentee. As to the erroneous statement that the 001 study was reported in O'Donnell 2004, Locke JA agreed with the respondents that it was merely a "slip of the pen", which "may at any time be corrected by the Court" pursuant to rule 397(2) of the Federal Courts Rules.

Identifying and applying gap between state of the art and inventive concept
The Federal Court of Appeal also dismissed Janssen's arguments that the trial judge had failed to:

  • explain how AA contributed to the treatment of cancer independent of PN; and
  • consider the treatment of refractory prostate cancer in his obviousness analysis.

Locke JA found that there was sufficient evidence to support the trial judge's conclusion that the invention was obvious to try. Whether the skilled person trying the invention would know that AA had anti-cancer effects independent of the combination was not critical – it was enough that a skilled person would have "expected" that each of AA and PN would contribute. As to the second error, the phrase "excluding those being refractory patients" in the trial judge's decision was simply a clerical error and had been intended to read "including".

Declaring that 422 patent is invalid
With respect to Apotex's counterclaim, Janssen argued that the validity of the non-asserted claims should not have been addressed in the trial decision, as they are not permissible under section 6(3)(a) of the Patented Medicines (Notice of Compliance) Regulations (the Regulations). The Federal Court of Appeal disagreed. Having regard to the objectives of the Regulations as set out in the Regulatory Impact Analysis Statement, the Court held that the intention of the Regulations is to leave to the Federal Court the discretion to permit a counterclaim that includes non-asserted claims and declined to interfere with the exercise of discretion. However, the Court left open the question of whether a defendant to a section 6(1) action may bring such a counterclaim as of right.

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(1) Janssen Inc v Apotex Inc, 2022 FCA 184.