Federal Court Reaffirms Disclosure Requirement for Sound Prediction of Compound Patent

On January 15, 2016, Canada’s Federal Court released the decision of Barnes J in Eli Lilly Canada v Hospira Healthcare, 2016 FC 47, dismissing a prohibition application brought by Eli Lilly Canada Inc (Lilly) against Hospira Healthcare Corporation (Hospira) regarding its proposed generic versions of Lilly’s cancer drug ALIMTA® (pemetrexed disodium).

The patent at issue is Canadian Patent No. 1,340,794 (794 Patent), which is a compound patent claiming a class of pyrrolopyrimidine derivatives including pemetrexed that are useful as antitumor agents.  It was common ground that the vast majority of the claimed compounds (in the thousands) were not specifically disclosed, made, or tested by the Canadian filing date.  The key issue was whether the utility promised in the 794 Patent for the untested compounds would nonetheless have been soundly predicted from the results for the tested compounds. 

Barnes J was not persuaded by the finding in AstraZeneca v Apotex, 2014 FC 638 that the disclosure requirement for sound prediction was limited to new use patents (reported previously in E-TIPS® newsletter here).  He concluded that the utility of the untested compounds was not soundly predicted, noting that “small structural differences to classical antifolates can result in dramatic differences in biological activity”.  As a result, the skilled person could not extrapolate the antifolate activity of an untested compound from the data for the tested compounds.

Lilly did not appeal Barnes J’s decision and Hospira has obtained market approval for its generic pemetrexed products.