SAN FRANCISCO -- Jury deliberations began late Wednesdayhere in the trial of Xoma Corp.'s patent infringement suitagainst Centocor Inc. involving their competing antibodyproducts for treatment of gram-negative sepsis.

The jury must decide whether Centocor Inc. has proved itscontention that claim 7 of Xoma's patent is invalid by clear andconvincing evidence -- evidence that produces a firm belief orconviction that a fact is true, according to instructions issuedat the close of the trial Wednesday by U.S. District Court JudgeRobert H. Schnacke.

Claim 7 describes a method to therapeutically treat a humanwith a gram-negative bacterial infection using an anti-lipid Amonoclonal antibody.

By comparison, to find literal infringement of Xoma's patent,jurors must conclude that Xoma proved its case by apreponderance of the evidence, Schnacke said. This is a lowerstandard than "clear and convincing evidence," requiring onlythat a fact is more likely so than not so, Schnacke said.

At issue is whether Centocor's HA-1A antibody competitivelyinhibits Xoma's E5. If it does, Centocor is infringing Xoma'spatent.

In his closing arguments earlier in the day, Donald Dunner,counsel for Malvern, Pa.-based Centocor, said that Claim 7 ofXoma's patent is invalid because the language of the claim isindefinite since it doesn't tell a person of ordinary skill in theart whether use of an antibody infringes; the descriptionrequirement isn't satisfied because the original patentapplication didn't specify competitive inhibition; and Claim 7is not new or novel because it was anticipated by prior artmore than a year before the patent application was filed.

A finding of literal infringement will result in an automaticfinding of infringement under the doctrine of equivalence,Schnacke said. But if the jury doesn't find literal infringement,it must still decide whether a preponderance of the evidenceshows infringement under the doctrine of equivalence.

Dunner told the jury that Centocor wasn't infringing under thedoctrine of equivalence because Xoma can't prove reverse-competitive inhibition -- that E5 inhibits HA-1A by binding tothe same epitope. In addition, he said, Xoma didn't prove thatthe two products work in substantially the same way or thatthey produce substantially the same result.

Gerald Sobel, lead counsel for Xoma, presented the Berkeley,Calif., company's closing arguments on Tuesday.

The jury must return unanimous verdicts on the issues.

Xoma shares (NASDAQ:XOMA) closed down 25 cents onWednesday at $16.25. Centocor (NASDAQ:CNTO) was down 88cents to $51.50.

-- Karen Bernstein BioWorld Staff

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