By Randall Osborne

Fueled by technology gained in its merger last fall with GenPharm International Inc., Medarex Inc. signed its fourth corporate partnership — a potential $9 million deal to produce fully human antibodies for Schering AG.

Under the research collaboration and license agreement, Annandale, N.J.-based Medarex will make antibodies to a proprietary antigen from Schering, of Berlin.

The agreement includes research and development payments from Schering, a license fee and milestone payments, plus royalties.

Medarex acquired GenPharm, of Palo Alto, Calif., for $65 million in October, and gained as part of the takeover the HuMab-Mouse strain, which produces high-affinity, fully human antibodies to a target antigen in about three to six months. (See BioWorld Today, Oct. 28, 1997, p. 1.)

Other Medarex partnerships using the HuMab-Mouse technology are with Centocor Inc., of Malvern, Pa.; LeukoSite Inc., of Cambridge, Mass.; and Eisai Co. Ltd., of Tokyo. The Centocor deal involves payments that could exceed $50 million plus royalties. (See BioWorld Today, March 4, 1997, p. 1.)

On its own, Medarex developed bispecific antibodies, which are designed to attach to disease targets and immune system killer cells simultaneously, thus creating a "target and trigger" strategy. One portion of the bispecific antibody binds to the tumor cell or infectious agent and the other binds to the trigger cell on killer cells, for a one-two punch against the target.

"With the GenPharm mouse, we can create fully human targeting halves," said Michael Appelbaum, president and COO of GenPharm International, a subsidiary of Medarex. "We have a discovery technology that feeds right into our bispecific platform."

Anticancer Drugs Entering Late-Stage Trials

Medarex has collaborations in cancer with Novartis AG, of Basel, Switzerland; Merck KGaA, of Darmstadt, Germany; and Centeon LLC, of King of Prussia, Pa. These deals predate the takeover of GenPharm.

Kevin Tang, an analyst with BT Alex. Brown Inc., of New York, rated Medarex a "strong buy." Two of the company's lead cancer products could be launched in 2000 and 2001, pushing the company into profitability, Tang said in a report.

One of the cancer products, MDX-210 for prostate and kidney cancer, is "just finishing up Phase II," Appelbaum said. Medarex's partner for that drug is Novartis, which has agreed to pay up to $11 million in milestones upon completion of Phase II and the start of Phase III trials.

Medarex's most-developed product is an immunoconjugate known as MDX-RA for the prevention of secondary cataracts in patients who undergo cataract surgery. MDX-RA, which is in Phase III trials, was acquired with the $8.6 million buyout in 1997 by Medarex of Houston Biotechnology, of The Woodlands, Texas. (See BioWorld Today, Dec. 12, 1996, p. 1.)

Medarex's shares (NASDAQ:MEDX) closed Thursday at $5.625, down $0.125. *