Eisai vs. Dr. Reddy’s: Lenvatinib Patent Consent Judgment Blocks Generic Entry

Case Overview

A negotiated consent judgment in the U.S. District Court for the District of New Jersey has reinforced Eisai’s patent fortress around lenvatinib — the active ingredient in the blockbuster oncology drug **Lenvima®** — blocking Dr. Reddy’s Laboratories from commercializing its generic equivalent ahead of patent expiration. Case No. **1:24-cv-06765**, filed June 6, 2024, and closed September 25, 2025, offers a sharply instructive example of how branded pharmaceutical companies leverage ANDA litigation strategically to defend high-value oncology franchises.

For patent attorneys, IP professionals, and R&D teams navigating the pharmaceutical patent landscape, this case illustrates the enduring power of layered patent portfolios, the tactical utility of consent judgments in Hatch-Waxman litigation, and the continuing vulnerability of ANDA filers who challenge robust compound and formulation patent estates.

The Parties

The Patents at Issue

Three patents were identified in the litigation:

• • US10,407,393 B2 — covers formulation or method-of-use aspects of lenvatinib
• • US11,186,547 B2 — covers additional compound or formulation claims for lenvatinib
• • US7,612,208 B2 — an earlier foundational patent in the lenvatinib portfolio

The consent judgment specifically confirmed that US10,407,393 and US11,186,547 are valid, enforceable, and would be infringed by DRL’s proposed generic product.

The Verdict & Legal Analysis

Outcome

The parties entered a Consent Judgment and Injunction stipulated by both sides and endorsed by the court. Crucially, the judgment contains an express acknowledgment by DRL that:

“United States Patent Numbers 10,407,393 and 11,186,547 are valid and enforceable with respect to the DRL Product and any Generic Equivalent, and would be infringed by the manufacture, use, sale, offer to sell, importation or distribution of the DRL Product in the United States.”

This is not a neutral dismissal. DRL affirmatively conceded validity and infringement — a significant strategic concession that goes beyond a standard covenant-not-to-sue or no-contest settlement. No monetary damages were disclosed; the settlement terms are governed by a confidential Settlement Agreement. An injunction was entered prohibiting DRL and its affiliates from making, using, selling, offering to sell, importing, or distributing the generic lenvatinib product prior to expiration of both patents. All claims, counterclaims, affirmative defenses, and demands were dismissed with prejudice.

Key Legal Issues

The case arose as a standard **Hatch-Waxman infringement action** triggered by DRL’s ANDA paragraph IV certification — a statutory assertion that Eisai’s listed patents are invalid, unenforceable, or not infringed. Eisai’s timely suit invoked the automatic 30-month stay of FDA approval, preserving market exclusivity during litigation.

DRL’s unqualified acknowledgment of validity and infringement in the consent judgment suggests the parties reached a resolution that strongly favored the patent holder’s legal position. In Hatch-Waxman practice, such express admissions are strategically significant, as they foreclose DRL’s ability to later assert invalidity in collateral proceedings involving the same patents.