West Coast Editor

Geron Corp. granted license rights to Revivicor Inc. that allows the transgenic pig firm to use Geron's nuclear transfer technology for animal cloning and make human proteins such as polyclonal antibodies for vaccines from animal blood. In return, privately held Revivicor is giving Geron an equity interest, plus a royalty on future revenues.

The deal adds to about a dozen such arrangements with licensees, said David Greenwood, chief financial officer of Menlo Park, Calif.-based Geron.

"Most of them are structured in this fashion, where we have an equity interest up front," he said, calling the interest in Revivicor "substantial," but declining to provide further details.

Geron's stock (NASDAQ:GERN) closed Tuesday at $6.95, down 2 cents.

Revivicor, whose former parent company is Edinburgh, UK-based PPL Therapeutics plc - maker of "Dolly," the cloned sheep - is working to produce genetically modified pigs from which cells, tissues and organs can be used for transplants into humans that will not be rejected. PPL "folded its tent" last year, Greenwood noted.

"We did this [deal] for strategic reasons," he said. "We're just not an [agricultural] company," adding that "I don't know if you would call xenotransplantation human therapeutics or ag," but in any case the efforts by Revivicor fall outside Geron's area of interest.

Revivicor's team produced the world's first cloned pigs in March 2000, as well as the first cloned knockout pigs lacking both copies of the gene responsible for triggering acute immune rejection in humans - the alpha 1,3 gal gene. Now the Geron technology will be used for second-generation animals.

Preclinical trials have begun to test the use of xenograft hearts, kidneys and islets, in collaboration with its partners at the University of Pittsburgh Medical Center and the London Health Sciences Center in Canada. The Pittsburgh center includes transplant pioneer Thomas Starzl, who developed cyclosporine and is working with Revivicor on pig-to-primate studies, while examining the long-term survival of pig organs along with islet-cell transplants to reverse diabetes.

"The thought there would simply be, if you can deal with rejection issues, you might be able to use pig islets," Greenwood said.

Polyclonal antibodies made in the blood of pigs, covered by one of two licenses granted by Geron, will be studied as remedies for infectious agents, which include antibiotic-resistant bacteria, viruses and potential biowarfare pathogens, as well as for clearance of toxins.

Geron, which has licensed nuclear transfer technology to firms other than Revivicor, is working on cancer treatments based on its telomerase technology and cell-based drugs using embryonic stem cells. The firm raised $40 million last week. (See BioWorld Today, Nov. 12, 2004.)