West Coast Editor

Cancer-focused Agensys Inc. nailed down its second big pharma deal of the month, licensing its Phase I monoclonal antibody for prostate stem cell antigen (PSCA) to Merck & Co. Inc. for $17.5 million up front and as much as $11.5 million more over the next year, depending on milestones.

If the drug, known as AGS-PSCA, is launched, Agensys would get more milestone payments, adding another $95 million - an amount that could increase to upward of $170 million if the compound is approved for multiple oncology indications.

"We can't give a finer breakdown than what is in the press release, but the milestones are the standard kinds," tied to phases of development, market approvals and the like, said Paul Kanan, vice president of operations and chief financial officer for Santa Monica, Calif.-based Agensys.

Aya Jakobovits, chief scientific officer for the company, said that although the first indication will be hormone-refractory prostate cancer, the drug has shown promise against pancreatic and bladder tumors, as monotherapy and in combination with other drugs.

"We've put a lot of thought about additional studies we would like to initiate," she told BioWorld Today, based on "very strong efficacy that we have observed in animals." But the next steps will be determined in talks with Merck.

"PSCA is a proprietary target, so there's nobody else who's working [on it]," she said, adding that "there are not really too many antibodies currently under development" as targeted therapies.

The timeline for developing AGS-PSCA is "difficult to say" until more discussions are held with Merck, Jakobovits said. "What goes to our advantage is that it's a naked antibody, which means it doesn't need any type of payload technology."

Having proven itself "extremely safe" so far, the drug "has all the right features" for relatively quick development, she said.

Under the terms of the deal, Whitehouse Station, N.J.-based Merck and Agensys will co-develop and jointly fund AGS-PSCA for advanced prostate cancer and other indications through Phase II. The ongoing Phase I study at Memorial Sloan-Kettering Cancer Center and Johns Hopkins Kimmel Cancer Center uses supplies of the drug made by Agensys, which will keep manufacturing AGS-PSCA until production can be transferred.

Merck will lead the future worldwide clinical development program with what the companies described as "significant participation" by Agensys, with Merck taking primary responsibility for commercialization and commercial manufacture.

Agensys retains an option to take part in Phase III efforts in the U.S.

AGS-PSCA is a high-affinity, fully human IgG1k monoclonal antibody directed to PSCA, generated using Fremont, Calif.-based Abgenix Inc.'s XenoMouse technology, which Jakobovits was instrumental in developing when she worked for that firm. PSCA is expressed at significant levels on tumor cells from a majority of patients with all stages of prostate, pancreatic and bladder cancers.

Earlier this month, Agensys entered a three-year research agreement with Sanofi Pasteur, the vaccines business of Sanofi-Aventis Group, of Paris, to collaborate on vaccines for colorectal and prostate cancers. The deal gave Sanofi exclusive access to a portfolio of Agensys' proprietary targets, plus an option for exclusive worldwide licenses for up to six selected targets. Financial terms were not disclosed.

Agensys also has a licensing arrangement, signed last year, with South San Francisco-based Genentech Inc., under which the former could earn more than $90 million. Genentech is paying for research, development and commercialization rights to therapeutic and diagnostic products surrounding two cancer targets. (See BioWorld Today, July 23, 2004.)

Kanan said Agensys has "a lot of antibodies under development right now for other proprietary targets, and as we develop these we'll make a decision on a case-by-case basis" whether to partner them.

The company believes it can "carry [some of them] a very long way" on its own and maybe "all the way through to approval," he added.