On 16 April 2026, the US Court of Appeals for the Federal Circuit published its decision in an appeal by Teva Pharmaceuticals in proceedings commenced in September 2018 alleging that Eli Lilly indirectly infringed Teva’s US patents 8586045, 9884907 and 9884908. The patents relate to methods of treating headache using humanised anti-CGRP antagonist antibodies, such as Teva’s Ajovy® (fremanezumab-vfrm).
In the proceedings before the US District Court for the District of Massachusetts, the jury found that Eli Lilly wilfully infringed the asserted claims of the patents via its Emgality® (galcanezumab-gnlm) and awarded Teva US$176.5 million in damages. The jury also found the asserted claims of the patents to be valid. The District Court subsequently overturned the jury’s verdict on validity, granting “judgment as a matter of law” (JMOL) that the asserted claims are invalid for lack of written description and enablement. Teva appealed to the Court of Appeals.
In relation to written description, which requires that the inventor of a patent “had possession of the claimed subject matter” of that patent at its filing date, the relevant dispute concerned whether the specification disclosed a representative number of species of the asserted claims’ genus of anti-CGRP antagonist antibodies. The Court of Appeals determined that the patents make clear that the claimed invention is the use of anti-CGRP antagonist antibodies to treat headache, not the antibodies themselves, and a reasonable jury could have found facts sufficient to show that the inventors had possession of the invention, including that methods of making the antibodies, and humanisation of antibodies, were well-known in the prior art.
In relation to enablement, which requires that the patent specification “must teach those skilled in the art how to make and use the full scope of the claimed invention without undue experimentation”, Eli Lilly argued that there was insufficient teaching in the specification for the large number of candidate antibodies included in the claimed genus. However, the Court concluded that because the asserted claims were to a method of treatment (not to the antibodies themselves), and the specification disclosed that all the claimed antibodies worked for the claimed method of treatment, the District Court’s finding of no enablement was improper.