Mylan Pharmaceuticals ULC

Mylan Pharmaceuticals ULC in its patent litigation victory against Eli Lilly


Mylan Pharmaceuticals ULC




Intellectual Property

Date Closed

June 2023


Pharmaceuticals and Life Sciences

Lead Office



In ongoing litigation lasting years, Osler has been representing Mylan Pharmaceuticals ULC in defence of an action for patent infringement brought by Eli Lilly in relation to the blockbuster drug Tadalafil (Cialis).

In 2020, Osler successfully defended Mylan Pharmaceuticals ULC in an action for patent infringement brought by Eli Lilly regarding the drug tadalafil (CIALIS). As the first-to-market for generic tadalafil in Canada, Mylan faced potential patent infringement damages for several years of generic sales. In the almost month long trial, Osler’s multi-party defence team established that Eli Lilly’s patent was invalid on two separate grounds including obviousness and anticipation, resulting in a victory for Mylan.

The appeal of the decision was heard in March 2023, and the Court accepted Mylan’s and the other respondents’ arguments that the appeal would be unsuccessful even if a claim construction argument proposed by Eli Lilly was accepted, because the factual evidence led at trial, and associated facts found by the trial judge, established the obviousness of tadalafil dosing irrespective of construction of the claims. On June 2, 2023, Federal Court of Appeal therefore upheld the trial victory that invalidated Lilly’s Canadian Patent No. 2,371,684, a drug dosing patent that has been litigated around the world. This was a tremendous legal and commercial victory for Mylan.  Costs were awarded in Mylan’s favour both at trial and on appeal.

Mylan Pharmaceuticals ULC is a leading generics and specialty pharmaceutical company focused on manufacturing and marketing 1,400 different medicines to retail, wholesale, government and institutional customers.

Osler, Hoskin & Harcourt LLP advised Mylan Pharmaceuticals ULC with a team consisting of Brad White and Nathaniel Lipkus (Intellectual Property).