Wyeth v. Impax Laboratories, Inc.

526 F. Supp. 2d 474, 2007 U.S. Dist. LEXIS 91548, 2007 WL 4354985
CourtDistrict Court, D. Delaware
DecidedDecember 13, 2007
DocketCivil Action 06-222-JJF
StatusPublished
Cited by3 cases

This text of 526 F. Supp. 2d 474 (Wyeth v. Impax Laboratories, Inc.) is published on Counsel Stack Legal Research, covering District Court, D. Delaware primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Wyeth v. Impax Laboratories, Inc., 526 F. Supp. 2d 474, 2007 U.S. Dist. LEXIS 91548, 2007 WL 4354985 (D. Del. 2007).

Opinion

MEMORANDUM OPINION

JOSEPH J. FARNAN, District Judge.

This action was brought by Plaintiff Wyeth against Defendant Impax Laboratories, Inc. (“Impax”) alleging infringement of U.S. Patent Nos. 6,274,171 B1 (“the '171 patent”), 6,419,958 B2 (“the '958 patent”) and 6,403,120 B2 (“the '120 patent”) under the Hatch-Waxman Act in connection with Impax’s Abbreviated New Drug Application (“ANDA”) for a generic version of Wyeth’s Effexor ® XR. The issue currently before the Court is the claim construction of three terms and/or phrases from the patents-in-suit. The parties have briefed their respective positions on claim construction, and the Court has conducted a Markman hearing. This Memorandum Opinion represents the Court’s construction of the disputed claim terms and/or phrases.

I. BACKGROUND

The three patents-in-suit share the same specification and relate to a product marketed by Wyeth under the registered name Effexor ® XR. Generally, the asserted claims of the patents-in-suit pertain to methods for treating patients with depression or other disorders responsive to venlafaxine by administering an extended release formulation of venlafaxine hydrochloride that provides a therapeutic concentration of the drug over a 24 hour period and results in less nausea and vomiting than with an immediate release formulation of venlafaxine hydrochloride. The asserted claims are all method claims which require either peak blood plasma levels of venlafaxine within a specified time period or peak blood plasma levels of venlafaxine within specified concentrations. Some claims also provide that the claimed method result in “diminished incidences of nausea and emesis.”

Wyeth has asserted against Impax the following claims from the patents-in-suit: claims 20-25 of the '171 patent, claims 1-6 of the '958 patent and claims 1, 2, 13 and 14 of the '120 patent. From these claims, the parties have identified three disputed claim terms and/or phrases: (1) “extended release formulation,” (2) “diminished incidences of nausea and emesis,” and (3) “a method for eliminating the troughs and peaks of drug concentration in a patient’s *477 blood plasma.” The following claims from the '171 patent are illustrative of how these terms and/or phrases are used in all of the asserted claims:

20. A method for providing a therapeutic blood plasma concentration of venlafaxine over a twenty four hour period with diminished incidences of nausea and emesis which comprises administering orally to a patient in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.
21. A method for eliminating the troughs and peaks of drug concentration in a patients [sic] blood plasma attending the therapeutic metabolism of plural daily doses of venlafaxine hydrochloride which comprises administering orally to a patient in need thereof, an encapsulated extended release formula that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient.

The patents-in-suit have also been the subject of litigation between Wyeth and Teva Pharmaceuticals in the United States District Court for the District of New Jersey (the “Teva Litigation”). A Markman ruling was issued in that case concerning, among other things, two of the same terms asserted by Wyeth here. The parties settled the case before trial, and the New Jersey district court vacated its Markman ruling.

III. LEGAL STANDARD

Claim construction is a question of law. Markman v. Westview Instruments, Inc., 52 F.3d 967, 977-78 (Fed.Cir.1995), aff 'd, 517 U.S. 370, 388-90, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996). When construing the claims of a patent, a court considers the literal language of the claim, the patent specification and the prosecution history. Markman, 52 F.3d at 979. Of these sources, the specification is considered the single best guide for discerning the meaning of a claim. Phillips v. AWH Corporation, 415 F.3d 1303, 1312-1317 (Fed.Cir.2005).

A court may consider extrinsic evidence, including expert and inventor testimony, dictionaries, and learned treatises, in order to assist it in understanding the underlying technology, the meaning of terms to one skilled in the art and how the invention works. Phillips, 415 F.3d at 1318-19; Markman, 52 F.3d at 979-80 (citations omitted). However, extrinsic evidence is considered less reliable and less useful in claim construction than the patent and its prosecution history. Phillips, 415 F.3d at 1318-19 (discussing “flaws” inherent in extrinsic evidence and noting that extrinsic evidence “is unlikely to result in a reliable interpretation of a patent claim scope unless considered in the context of intrinsic evidence”).

In addition to these fundamental claim construction principles, a court should also interpret the language in a claim by applying the ordinary and accustomed meaning of the words in the claim. Envirotech Corp. v. Al George, Inc., 730 F.2d 753, 759 (Fed.Cir.1984). If the patent inventor clearly supplies a different meaning, however, then the claim should be interpreted according to the meaning supplied by the inventor. Markman, 52 F.3d at 980 (noting that patentee is free to be his own lexicographer, but emphasizing that any special definitions given to words must be clearly set forth in patent). If possible, claims should be construed to *478 uphold validity. In re Yamamoto, 740 F.2d 1569, 1571 (Fed.Cir.1984) (citations omitted).

IV. CONSTRUCTION OF THE DISPUTED TERMS AND/OR PHRASES

A. “Extended Release Formulation”

With respect to the term “extended release formulation,” Impax contends that the term requires specific ingredients referred to in the specification. Specifically, Impax contends that “extended release formulation” means “a formulation comprising venlafaxine, microcrystalline cellulose, and optionally, HPMC coated with a mixture of ethyl cellulose and HPMC in an amount needed to provide a specific unit dosage administered once-a-day to provide a therapeutic blood plasma level of venla-faxine over the entire 24 hour period of

Free access — add to your briefcase to read the full text and ask questions with AI

Related

Wyeth v. Sandoz, Inc.
703 F. Supp. 2d 508 (E.D. North Carolina, 2010)
Wyeth v. Lupin Ltd.
579 F. Supp. 2d 711 (D. Maryland, 2008)

Cite This Page — Counsel Stack

Bluebook (online)
526 F. Supp. 2d 474, 2007 U.S. Dist. LEXIS 91548, 2007 WL 4354985, Counsel Stack Legal Research, https://law.counselstack.com/opinion/wyeth-v-impax-laboratories-inc-ded-2007.