Fed. Cir. Tightens Enablement Rules for Method of Treatment Patents
Life sciences companies and patent counsel filing method of treatment claims before clinical data is available must revise drafting strategies, after a Federal Circuit ruling invalidated a $107.5 million verdict by finding such claims unenabled when they lack patient-level dosing guidance and rely solely on unvalidated in vitro results.
On July 9, 2026, the U.S. Court of Appeals for the Federal Circuit issued a precedential ruling in Wyeth LLC v. AstraZeneca Pharmaceuticals LP, affirming a district court’s finding that Wyeth’s patents for methods of treating EGFR inhibitor-resistant non-small cell lung cancer were invalid for lack of enablement. The court held the patents’ in vitro cell assay data and broad, unvalidated dose ranges were insufficient to enable the claimed “unit dosage” requirement for patient administration, as disclosed doses for two of three candidate drugs exceeded safe human tolerance levels. The ruling clarifies method of treatment claims require more than lab efficacy data when claim language mandates patient-level therapeutic effect, and that specification language emphasizing dosing variability can support non-enablement findings. Life sciences innovators should avoid overbroad claim language importing patient efficacy requirements without corresponding specification support, limit language highlighting dosing unpredictability, and prioritize filing dosing claims after clinical trial data is available to strengthen enablement.