Scilex Pharmaceuticals v. Aveva — Lidocaine Patch Claims Require the Claimed Agent to Dissolve the Drug

Background

Scilex and its co-plaintiffs asserted three patents covering non-aqueous lidocaine patches against Aveva’s proposed generic version of ZTlido. They conceded there was no literal infringement and argued instead that Aveva’s use of isostearic acid and oleyl alcohol was equivalent to the claimed two-component dissolving agent made of an organic acid and a polyalcohol.

The Court’s Holding

The Federal Circuit affirmed the judgment of noninfringement. Reading the claims with the specification and prosecution history, the court held that the claimed “dissolving agent” must do two jobs: dissolve the lidocaine and maintain it in a non-crystalline state in the finished patch. During prosecution, the applicant repeatedly described lidocaine as dissolved in the claimed organic acid and polyalcohol. Those consistent statements informed claim meaning even if they did not amount to a formal disclaimer.

Aveva instead used n-heptane to dissolve lidocaine. Because that solvent was not equivalent to the claimed dissolving agent, Scilex could not prove infringement under the governing construction. The panel therefore did not reach the district court’s alternative claim-vitiation and prosecution-history-estoppel rulings.

Key Takeaways

• Repeated prosecution statements can define how a skilled reader understands a claim term without satisfying the stricter test for disclaimer.
• The doctrine of equivalents cannot rescue an infringement theory when the accused product assigns the claimed function to a materially different component.
• Patent drafting and prosecution descriptions of what a component does can become decisive in later ANDA litigation.

Why It Matters

The decision reinforces that prosecution history is not merely an estoppel tool. It can shape ordinary claim construction, especially where an applicant repeatedly explains the functional role of a claimed ingredient.