According to the official website of the US Court of Appeals for the Federal Circuit, on 16 April 2026, Teva Pharmaceutical Industries won a patent infringement case concerning a migraine drug. The Federal Circuit reinstated the $176.5 million (approximately 1.2 billion yuan) infringement damages award against Eli Lilly and overturned the district court’s contrary ruling.

The case dates back to 2018, when Teva and Eli Lilly received US Food and Drug Administration (FDA) approval for their migraine drugs Ajovy (fremanezumab) and Emgality (galcanezumab-gnlm) within 13 days of one another. Teva subsequently sued Eli Lilly, alleging that its drug Emgality infringed three patents relating to the CGRP pathway for the treatment of headaches.

In 2022, a federal jury in Boston found Eli Lilly guilty of willful infringement and ordered it to pay $176.5 million in damages, whilst also ruling that Eli Lilly had failed to prove the patents invalid. However, in 2023, District Court Judge Alison Burroughs overturned the verdict on the grounds that Teva’s patent claims were overly broad, lacked adequate written description and non-obviousness, and that the antibodies in the two drugs differed.

In reinstating the jury’s verdict, the Federal Circuit noted that the core of Teva’s patent lies in the method itself of using a specific type of antibody to treat migraine, rather than the chemical structure of the antibody, and therefore the claims are valid. The judges stated that the district court had erred in substituting its own judgement for the jury’s reasonable findings, and that Eli Lilly had failed to prove Teva’s patent invalid by “clear and convincing evidence”. Furthermore, the court upheld the jury’s assessment of the prior art, finding that Eli Lilly had failed to sufficiently demonstrate that the technology in question was ‘common knowledge’ as of the priority date.

The case will now be remanded to the US District Court for the District of Massachusetts for implementation of the Federal Circuit’s ruling. IP Finance will continue to monitor developments.

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