HOECHST ALLEGES COGNEX INFRINGEMENT OF PATENT
HOECHST ALLEGES COGNEX INFRINGEMENT OF PATENT in a suit filed Sept. 30 in Wilmington, Del. federal court. Hoechst-Roussel Pharmaceuticals is charging Warner-Lambert with infringing a composition and use patent (#4,631,286) for a class of compounds called acridines, patented as "useful in the treatment of various memory dysfunctions characterized by decreased cholinergic function, such as Alzheimer's disease." Acridines are also patented as having utility "to inhibit the enzyme cholinesterase and thereby increase acetylcholine levels in the brain." The "286 patent was filed Oct. 25, 1984 and issued to Hoechst in Dec. 23, 1986. The inventors are Gregory Shutske and Frank Pieffat. Warner-Lambert began shipping the cholinesterase inhibitor Cognex (tacrine) at the end of September after receiving FDA approval Sept. 9 for the treatment of patients with "mild to moderate dementia of the Alzheimer's type" ("The Pink Sheet" Sept. 13, p. 6). Cognex labeling notes that it "presumably acts by elevating acetylcholine released by the still intact cholinergic neurons." Warner-Lambert described the Hoechst suit as without merit. Hoechst is completing studies of its potential Alzheimer's treatment, Mentane (voinacrine) that were requested by FDA's Peripheral & Central Nervous System Drugs Advisory Committee last November after the committee denied the company's Treatment IND request. Hoechst had filed the Mentane NDA five months before the advisory committee meeting based on one pivotal trial and interim results from an ongoing study ("The Pink Sheet" Nov. 9, 1992, p. 5). The Hoechst patent claims that its acridine compounds are "in general less toxic" than tacrine and some of the compounds "exhibit antidepressant activities, which activities being particularly helpful for patients suffering from Alzheimer's disease." The discussion of antidepressant activities in the patent might be an indication of a possible Hoechst strategy for differentiating Mentane from Cognex in a clinical and/or marketing context. The lawsuit seeks preliminary and permanent injunctions to prevent further infringement of the patent and treble damages. Attorneys William Wade and Thomas Beck of the Wilmington law firm, Richards, Layton & Finger, are representing Hoechst. Of counsel are Herbert Schwartz and Kenneth Herman of the New York City firm Fish & Neave.
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