The U.S. Patent and Trademark Office has issued a broad patentfor Centocor Inc.'s Centoxin, a monoclonal antibody to treatgram-negative bacteremia and septic shock.

Analysts said the patent further strengthened Centocor's leadover rival Xoma Corp., driving Centocor stock (NASDAQ:CNTO)up $3.50 to $53.50.

The patent is comparable to a broad European composition ofmatter patent on Centoxin that issued in July, said Centocorspokesman Richard Koenig. The U.S. patent contains additionalmethod claims that aren't generally allowed in Europe.

"The patent relates to more than Centoxin alone," Koenig said."We think a reading of the patent will lead anybody to concludethat the types of antibodies covered is a broad one."

The composition of matter and method patent, No. 5,057,598,includes claims relating to monoclonal antibodies used intreating gram-negative bacterial infections, to pharmaceuticalcompositions comprising such antibodies, and to a method oftreating infections with such pharmaceutical compositions.

Koenig declined to speculate on whether the patent coversXoma's E5 antibody for gram-negative sepsis.

"At the moment, we're not really confronted with enforcementissues. No one's on the market, and on the basis of what weheard at the FDA advisory panel, there's reason to believe wecould be out there by ourselves," said Koenig. "So we're notspending much time on it as long as it appears to be moot. Atthis point, we don't have any plans to sue anybody, and mostparticularly that includes Xoma."

At an advisory committee meeting in September, the Food andDrug Administration said it wasn't ready to act on E5.

A spokeswoman for Berkeley, Calif.-based Xoma said thecompany has received a copy of the patent claims and isreviewing them. Xoma has sued Centocor of Malvern, Pa.,alleging that Centoxin has infringed Xoma's patent No.4,918,163 for use of antibodies that bind to the same bacterialsite as E5.

Xoma stock (NASDAQ:XOMA) was unchanged at $15.

Merrill Lynch analyst Stuart Weisbrod said it is almost a mootpoint whether or not Centocor's patent could block Xoma"because the Xoma product doesn't work. Centocor doesn't haveto do anything unless the Xoma product looks approvable."

Weisbrod said he has always assumed that the trial of thepatent infringement suit would lead to a narrowing of Xoma'spatent to cover only mouse antibodies, since that's what Xomahas reduced to practice. Closing arguments in the SanFrancisco trial are scheduled to begin Oct. 21.

Analyst Mark Simon of Robertson, Stephens & Co. echoedWeisbrod's sentiments. "This fills out (Centocor's) monopolyposition in Europe and the U.S., both in terms of patents andaccess to markets," he said. "We don't think there's a reason tosue Xoma since it's unclear if Xoma will reach market."

-- Karen Bernstein BioWorld Staff

(c) 1997 American Health Consultants. All rights reserved.