On August 14, 2024, the District Court for the District of Delaware vacated a $107.5 million jury verdict award against AstraZeneca Pharmaceuticals. The court concluded that two patents owned by Wyeth LLC, a subsidiary of Pfizer Inc., were invalid due to both lack of enablement and lack of written description under 35 U.S.C. § 112(a), specifically for failing to provide support for a safe and effective dosage.
In 2021, Wyeth filed a lawsuit against AstraZeneca, alleging that sales of AstraZeneca’s anti-cancer drug, Tagrisso, induced infringement of several claims of Wyeth’s U.S. Patents Nos. 10,603,314 and 10,596,162. Initially, a jury found in favor of Wyeth and awarded damages. AstraZeneca then filed a motion for judgment as a matter of law, arguing that no reasonable jury could have found that (1) AstraZeneca induced infringement of the patents-in-suit, (2) the patents were valid, or (3) Wyeth suffered damages. The Court granted AstraZeneca’s motion, but only on the question of invalidity, citing a lack of enablement and a lack of written description, while rejecting arguments related to anticipation and obviousness.
In 2023, Tagrisso generated nearly $5.8 billion in revenue for AstraZeneca. Had Pfizer identified a unit dosage that could be administered daily at a safe yet therapeutically effective level in the two patents allegedly infringed by Tagrisso, AstraZeneca may lose a multiple billion-dollar drug. To fend off competitors, a patent for method of treatment should describe a completed invention, not an unfinished project.
Lack of Enablement. AstraZeneca challenged three aspects of the asserted claims as not being enabled. While the court declined to grant judgment on the other grounds, it concluded that “no reasonable jury could find that the patents-in-suit enabled a Person of Ordinary Skill in the Art (POSA) to administer a unit dosage of any irreversible EGFR inhibitor covered by the claims to a patient without undue experimentation.” Wyeth’s expert agreed at trial that some dosages of the compounds could be toxic or even fatal to patients. However, the specification of Wyeth’s patents did not disclose any working examples of unit dosages administered to patients, and there is no non-toxic therapeutic range for any given compound.
The court held that a POSA would need to undertake undue experimentation to find a “unit dosage” that would not fatally poison a patient for each of the myriad irreversible EGFR inhibitors encompassed within the scope of the asserted claims and, thus, the patents-in-suit did not enable a POSA to daily administer a unit dosage to a patient.
Lack of Written Description. AstraZeneca’s arguments with respect to written description mirrored its arguments with respect to enablement. As above, the court agreed with AstraZeneca that “the patents-in-suit do not contain a written description that ‘clearly allow[s] persons of ordinary skill in the art to recognize that [the inventor] invented what is claimed,’ i.e. a unit dosage of an irreversible EGFR inhibitor that can be administered daily to patient.” Furthermore, the Court found that “although the specification discusses a suggested range for a unit dosage between 2 and 500 milligrams per day, nothing in the specification suggests that the inventors in fact had identified a unit dosage of the specified compounds that could be administered daily to a patient at levels high enough to show the desired therapeutic effect”. Therefore, a POSA would be required to engage in undue experimentation to determine an administrable unit dosage for different compounds covered by the asserted claims of Wyeth’s patent. As almost an aside, the Court explained that “the patents-in-suit perhaps contain a sufficient written description of a process for disrupting EGFR pathways and eliminating cancer cells, but that is not the extent of what the patents claim.” In other words, with respect to a method of treatment involving administering daily a unit dosage to a patient, the specification describes “an unfinished project, not a completed invention” by failing to identify a safe but effective dosage, and thus the patents are invalid.