Eli Lilly and Co. notified Canada it plans to file a trade complaint, claiming court decisions invalidating one of the company’s patents breach international obligations.

Companies that produce generic drugs have challenged Lilly’s patent for Strattera, used for treating attention-deficit disorder. The Indianapolis-based firm claims recent decisions by Canadian courts invalidating 17 drug patents over “utility” requirements have made the country an outlier among major developed countries.

“All domestic avenues of appeal in Canada have been exhausted and the only recourse left to Lilly is to seek arbitration,” the company said in a statement. “Lilly did not make this decision lightly.”

The Canadian court decision shows the “sharp divergence of Canadian law from Canada’s international obligations and internationally accepted standards,” the company said. Strattera generated $457.5 million in global sales in the first nine months of the year for Lilly.

Lilly filed a notice that it will seek arbitration under the terms of the North American Free Trade Agreement. The company said it hopes to resolve the dispute “through consultations and negotiations.”

Last year, Lilly won an appeals court ruling in the U.S. that overturned a judge’s decision invalidating the Strattera patent.