Federal Circuit IP
Teva Pharmaceuticals International GmbH v. Eli Lilly and Company
Teva Pharmaceuticals International GmbH v. Eli Lilly and Company
CAFC No. 2024-1094, Decided Apr. 16, 2026
(Prost, Cunningham, Andrews)
Background:
- D. Mass.: Teva sued Lilly, alleging Lilly’s Emgality product infringed three “headache patents” covering methods of treating headache with humanized anti-CGRP antagonist antibodies. Teva also asserted separate antibody patents. The headache patents claimed methods of treatment, not the antibodies themselves.
- CGRP is involved in headache signaling; anti-CGRP antibodies block CGRP activity. Humanization converts murine antibodies into a form less likely to be rejected by the human immune system.
- IPRs: Lilly challenged both patent groups. The headache patents survived, while the antibody patents were held unpatentable. The Federal Circuit affirmed both results, and Teva dismissed the antibody-patent claims.
- Trial and JMOL: The jury found willful infringement and rejected Lilly’s written description and enablement defenses. After trial, the district court granted JMOL of invalidity under § 112 ¶ 1, finding the patents disclosed only one humanized antibody and did not support or enable the full claimed genus. Teva appealed.
Issue: whether JMOL of invalidity under § 112 ¶ 1 was proper where the asserted method claims recite using a genus of humanized anti-CGRP antagonist antibodies to treat headache, but the specification disclosed only one humanized antibody.
Holding: Reversed and remanded.
Federal Circuit Analysis:
- Written Description: reversed.
- Lilly argued the specification disclosed only one humanized anti-CGRP antagonist antibody and did not support the full claimed genus.
- The Federal Circuit rejected that framing. The claims were directed to methods of using humanized anti-CGRP antagonist antibodies to treat headache, not to the antibodies themselves.
- Although the specification disclosed only one humanized antibody, it also disclosed several murine anti-CGRP antagonist antibodies, prior-art methods for humanization, and the use of such antibodies to treat headache. Evidence also showed that anti-CGRP antagonist antibodies were well known and humanization was routine, including Lilly’s own prior IPR statements.
- No bright-line rule based on structural differences. Structural differences may be relevant, but they do not automatically defeat written description where the claims are directed to a method of using a known class of antibodies.
- Enablement: reversed.
- Lilly argued that the claims were too broad because a POSITA would need to screen many candidate antibodies to determine which ones antagonize CGRP and treat headache.
- The Federal Circuit again emphasized that the claims were method-of-treatment claims, not composition claims to the antibodies themselves. The relevant “research assignment” was not making every antibody in the genus, but using humanized anti-CGRP antagonist antibodies to treat headache. Because the specification taught that such antibodies treat headache, and the record supported that the antibodies and humanization methods were known, a reasonable jury could find the claims enabled.
Takeaways:
- Patent prosecutors:
- For method-of-treatment claims using a known genus, emphasize that the invention is the use of the genus, not necessarily the genus itself.
- When the broader class is known, the modification is routine, and the claimed use applies across the class, even one working humanized antibody may be sufficient.
- Patent challenger:
- Prior statements in IPRs can matter. Consider possible consequences in parallel district court litigation.