Federal Circuit Upholds Patent Invalidity for Lack of Enablement Due to Absence of Actual Dosage Disclosure

The Federal Circuit issued several significant patent rulings in early July 2026, addressing issues ranging from enablement and obviousness to claim construction and preliminary injunctions.

In Wyeth LLC v. AstraZeneca Pharmaceuticals LP (2024-2325), the court affirmed the district court’s judgment as a matter of law (JMOL) invalidating asserted claims of U.S. Patent Nos. 10,603,314 and 10,596,162 for lack of enablement. These patents relate to methods of treating gefitinib and/or erlotinib resistant non-small cell lung cancer (NSCLC) using irreversible EGFR inhibitors. Although a jury initially found infringement and no invalidity, the district court granted JMOL of invalidity, concluding that the patents did not enable a skilled artisan to administer the claimed “unit dosage” without undue experimentation.

The Federal Circuit agreed, emphasizing that the patent specification disclosed no working examples of unit dosages administered to patients. AstraZeneca’s unrebutted evidence showed that some disclosed dosage levels would be toxic, including those required to achieve therapeutic effects. Wyeth’s argument that the district court improperly altered claim construction post-verdict was rejected. The court explained that the claims inherently require administering a therapeutic unit dosage daily, a limitation that goes beyond killing cancer cells but does not demand full clinical safety standards akin to FDA approval.

Critically, the court found the specification failed to teach how to translate in vitro activity data into effective daily dosing regimens. Only three example compounds were disclosed, with no guidance on extrapolating in vivo dosing or calculating unit dosages. The court noted that some disclosed compounds would require dosages exceeding maximum tolerated levels in humans to be effective, reinforcing the lack of enablement. The court observed that while claiming a range of doses without clinical data is common, these patents were limited to dosage forms administered to patients but disclosed only broad, sometimes toxic dose ranges without actual dosages, leaving undue experimentation to practitioners.

In Intellectual Pixels Limited v. Sony Interactive Entertainment LLC (2024-2174), the court affirmed the Patent Trial and Appeal Board’s (PTAB) decision on remand holding claims 1–12 of U.S. Patent No. 10,681,109 unpatentable as obvious. The patent concerns methods for generating digital images using an external visual server. The court clarified that the PTAB did not exceed its mandate on remand by reconsidering issues related to image compression, as those issues were not decided in the prior appeal. The court found substantial evidence supported the PTAB’s conclusion that the primary prior art, Wiltshire, combined with a secondary reference, disclosed the claimed image generation and compression limitations.

In TrackTime, LLC v. Amazon.com Services LLC (2024-1102), the court vacated the district court’s ruling that claims of U.S. Patent No. 8,862,978 are indefinite and remanded for further proceedings. The district court had found the claims indefinite due to means-plus-function limitations lacking adequate structural disclosure. The Federal Circuit emphasized the need for a thorough § 112(f) analysis considering intrinsic evidence and industry understanding of the claimed executable program code. However, the court affirmed the invalidity of the only remaining asserted claim of U.S. Patent No. 8,856,638 as anticipated by prior art, rejecting arguments that the jury’s anticipation verdict lacked substantial evidence.

Finally, in Otsuka America Pharmaceutical, Inc. v. Hetero Labs Limited (2025-2016), the court affirmed a preliminary injunction preventing Hetero from launching a generic version of Nuedexta, a drug for treating pseudobulbar affect. The dispute centered on claim construction of the weight-to-weight ratio limitation between dextromethorphan and quinidine. The court sided with Otsuka, holding that the ratio includes both free-base and salt forms of the compounds, consistent with the specification and prosecution history. The court found that Hetero’s narrower construction excluding salt forms would exclude the patented product itself, an implausible result. Judge Dyk dissented in part, arguing the majority’s construction conflicted with the invention’s purpose to reduce quinidine exposure.

The court also vacated the district court’s waiver of the Federal Rule of Civil Procedure 65(c) bond requirement for the injunction, applying Third Circuit precedent that generally mandates a bond in commercial disputes. The case was remanded for determination of an appropriate bond amount.

These rulings underscore the Federal Circuit’s rigorous scrutiny of enablement, claim construction, and procedural requirements in patent litigation, particularly in the pharmaceutical and technology sectors.