Sandoz served a notice of allegation (“NOA”) upon Abbott and filed an Abbreviated New Drug Submission (“ANDS”) with respect to clarithromycin extended-release. The ANDS compared Sandoz’s product with BIAXIN XL marketed in Canada by Abbott. The NOA addressed four patents but only three were relevant to the appeal.

The judge had held the allegations of invalidity contained in the NOA to be unjustified with respect to Abbott’s ‘266 patent and issued an order prohibiting the Minister of Health from issuing a Notice of Compliance (“NOC”) to Sandoz until expiry of the ‘266 patent. The ‘266 patent protects an extended release formulation of clarithromycin. Sandoz had argued that a prior patent application disclosed an extended release formulation of azithromycin; a drug similar to clarithromycin. Sandoz submitted that as the formulation of the disclosed azithromycin product was almost identical to the formulation of the ‘266 patent (except, of course, for the different active ingredients) the skilled person would have considered it obvious to substitute clarithromycin for azithromycin . The judge disagreed and Sandoz appealed. The Federal Court of Appeal dismissed Sandoz’ appeal and highlighted, from the evidence, a number of differences between clarithromycin and azithromycin that it said did not make substitution obvious.

The judge had held that the allegation of invalidity for double patenting in respect of Abbott’s ‘395 patent was justified, notwithstanding that Abbott had dedicated its conflicting patent (‘541 patent) to the public. The dedication had been made by Abbott after the NOA had been served but before the prohibition hearing. The judge held that had the dedication been executed prior to the service of the NOA, Sandoz would have had no ground for alleging double patenting in respect of the ‘395 patent. Abbott cross-appealed this decision alleging, in part, that the proper date for considering the justification of allegations in a NOA is the date of the hearing not the date of the NOA. The FCA referred to various earlier cases (including one, Merck, from the Supreme Court of Canada) and allowed the cross-appeal. The FCA held that the judge had erred and should have considered the status of the ‘541 patent at the date of the hearing - and by then it had been dedicated to the public. So at the hearing the ‘541 patent was to have been read as if its claims had never issued and, as such, had the judge taken cognizance of the dedication she would have concluded that the allegation of double patenting was unjustified.

The full text of the decision can be found at: