Intrinsic Evidence Decodes Disputed Claim Terms

• Published date: 14 June 2023
• Subject Matter: Intellectual Property, Food, Drugs, Healthcare, Life Sciences, Patent
• Law Firm: Finnegan, Henderson, Farabow, Garrett & Dunner, LLP
• Author: Mr Pu-Cheng (Leo) Huang, Adriana Burgy and Stacy Lewis

Holding

In Newron Pharms. v. Aurobindo, No. 21-cv-843 (D. Del. April 14, 2023), the District Court of Delaware addressed several disputed terms in a patent related to the treatment of idiopathic Parkinson's disease. Based on the intrinsic evidence, the Court agreed with Plaintiff's proposed construction of terms like "stable dose of levodopa," "maintaining," and "a therapeutically effective stable dose of levodopa."

Background

Plaintiffs Newron Pharmaceuticals sued MSN Laboratories for infringement of U.S. Patent No. 8,076,515 ("the '515 patent"), U.S. Patent No. 8,278,485 ("the '485 patent"), and U.S. Patent No. 8,283,380 ("the '380 patent"). Before the court was the issue of claim construction.

1. "Stable Dose of Levodopa" of the '380 patent

The first term in dispute was "stable dose of levodopa." The claim at issue recites:

1. In a method of treating idiopathic Parkinson's disease in a patient receiving a stable dose of levodopa, the improvement comprising: concurrently administering safinamide, or a pharmaceutically acceptable salt thereof, on an oral dosage schedule of about 0.5 mg/kg/day to about 5 mg/kg/day, while maintaining the patient on a stable dose of levodopa.

Plaintiffs argued that "stable dose of levodopa" meant a dose that neither increased nor decreased. Id. at *4. Defendants claimed that the term was indefinite due to the lack of specific information on duration and frequency. Id.

The court analyzed the patent claims, noting that the use of the terms "maintaining" and "therapeutically effective" in the claims implied an unchanged dose. Id. The specification mentioned a clinical trial with patients on stable doses of dopamine agonist for at least four weeks, indicating that stable doses remained unchanged. Id. at *5.

The prosecution history supported the interpretation of a stable dose as an unchanged dose of levodopa. Id. The examiner considered that a stable dose referred to a dose that is neither increased nor decreased. Id. Considering the intrinsic record, including claims, specification, and prosecution history, the court concluded that "stable dose of levodopa" meant a dose that did not change. Id. Here, Defendants' argument of indefiniteness failed to show how one of ordinary skill in the art would not understand the claims' scope. Id. at *6. Moreover, the court found that the specification provided "an objective anchor" allowing one of ordinary skill in the art to determine the boundaries of the claim. Id.

2. "Maintaining" the...