USPTO Relies on Prosecution History of Claim Language
In a recent case decided by the Federal Circuit, Aptalis Pharmatech, Inc. v. Apotex Inc., the Appeal Court held that the prosecution history can explain the claim meaning, even without clear and unmistakable disclaimer of the claim scope.
The patents at issue are listed in the Orange Book for Aptalis’s AMRIX® product. A representative claim is as follows:
1. A pharmaceutical dosage form comprising a population of extended release beads, wherein said extended release beads comprise:
- an active-containing core particle comprising cyclobenzaprine hydrochloride as the active; and
- an extended release coating comprising a water insoluble polymer membrane surrounding said core, wherein said water insoluble polymer membrane comprises a polymer selected from the group consisting of…
The claim language in dispute was “the extended release coating….surrounding the core.” In particular, the defendant argued that its product did not infringe because it used a matrix-type formulation and not an extended release coating.
The district court had construed the claims broadly enough to encompass the Apotex product. On appeal, the defendant argued that “an ‘extended release coating’ is limited to a continuous outer film, not simply “[a] layer of any substance that is applied onto the surface of another.” The Federal Circuit agreed.
How Did They Reach a Decision?
First, the court considered the “coating” and “surrounding” language of the claims. The plain claim language suggests that the coating must be located outside of the core. Then, the court looked to the specification. And finally, the court considered the prosecution history, and found an expert Declaration that confirmed the claim construction.
The court rejected the plaintiff’s argument that the prosecution history is irrelevant to the claim construction question here because there is no clear and unmistakable disavowal of “claim scope.” But the court disagreed and held that the prosecution history can be evaluated to determine how a person of ordinary skill would understand a given claim term.
This holding should be a reminder that anything said during prosecution can and will be used in a court of law.
Contact me with questions or comments at silvia@salvadorilaw.com.
Silvia Salvadori, PhD
(212) 897-1938