The Federal Court has held a patent covering DEXILANT® (dexlansoprazole) for treating heartburn associated with gastroesophageal reflux disease to be invalid and not infringed by Apotex’s dexlansoprazole oral dose capsules. She awarded the defendant Apotex 40% of its legal fees and 100% of its reasonably incurred disbursements. A couple of noteworthy points can be found in the decision:
First, success at trial largely depended on the credibility of each party’s experts. The trial judge appeared to prefer the evidence of Apotex’s experts on most substantive points. Further, the plaintiff did not call an expert to address the evidence of Apotex’s pharmacokineticist. The judge noted this left an important evidentiary gap that favoured Apotex. Further, the trial judge was concerned because the plaintiff’s expert did not fully read the prior art referred to in his report relating to obviousness and anticipation. He, instead, relied on summaries provided by the plaintiff’s counsel. Although the trial judge did not strike the plaintiff’s expert evidence, it is clear from her reasons that she gave it less weight as a result.
Second, the trial judge found some of the fact evidence of the plaintiff to be inadmissible hearsay which could not be saved by the “business records exemption.” And further, because the plaintiff objected to some questions during examination for discovery, it could not lead the same evidence at trial from its fact witnesses.
Third, the patent was found invalid for lack of utility. The patentee could not prove it had demonstrated utility at the relevant date, so attempted to rely upon a sound prediction of utility. However, the trial judge did not consider the intravenous infusion data disclosed in the patent and modelled in the patent using PK-PD modelling to be sufficient to soundly predict utility of an “oral dosage form with two doses releasing as two pulses.”