By Blake Brittain

WASHINGTON, April 16 (Reuters) - A U.S. appeals court on Thursday revived a patent lawsuit that Teva Pharmaceutical TEVA.TA brought against Eli Lilly LLY.N over the companies' competing migraine drugs, after a judge previously overturned a $176.5 million jury verdict for Teva in the case.

The U.S. Court of Appeals for the Federal Circuit reversed a Massachusetts judge's decision that Teva's patents at issue in the case were invalid.

Spokespeople and attorneys for the companies did not immediately respond to requests for comment on the ruling.

Teva sued Lilly in 2018, alleging Lilly's migraine drug Emgality infringed patents related to Teva's rival drug Ajovy. Emgality earned Lilly more than $870 million in revenue worldwide in 2024, while Ajovy earned Teva $673 million last year, according to company reports.

A jury determined in 2022 that Lilly's drug infringed Teva's patents and awarded Teva $176.5 million in damages. U.S. District Judge Allison Burroughs overturned the verdict in 2023 after finding that Teva's patents covering the use of antibodies to inhibit headache-causing peptides were invalid.

Burroughs concluded that the patents were overly broad and did not enable scientists to recreate the antibodies without "undue experimentation."

The Federal Circuit determined on appeal that the patents were valid and sent the case back to Massachusetts federal court.

The case is Teva Pharmaceuticals International GmbH v. Eli Lilly & Co, U.S. Court of Appeals for the Federal Circuit, No. 24-1094.

For Teva: Kevin Martin of Goodwin Procter

For Lilly: William Raich of Finnegan Henderson Farabow Garrett & Dunner

Read more:

Eli Lilly ordered to pay $176.5 mln to Teva in U.S. migraine drug patent trial

US judge overturns Eli Lilly's $176.5 million loss in Teva patent case