By Matthew Willett

Abgenix Inc. boosted its efforts at fully human monoclonal antibody discovery, expanding its collaborations with both Immunex Corp. and CuraGen Corp. to develop, cumulatively, 140 new potential therapeutics over the next five years.

In an expansion of the July development and commercialization agreement with Immunex for ABX-EGF, an anticancer antibody directed against the epidermal growth factor receptor, Abgenix agreed to co-develop 10 cancer-specific antigen targets for development over five years, contributing half that amount from its own preclinical pipeline. (See BioWorld Today, July 28, 2000.)

That agreement in July to equally share in development costs and profits called for Immunex to head the product's commercialization after FDA approval. ABX-EGF is currently in a Phase I trial, and Abgenix, of Fremont, Calif., said it expects results early next year.

In the expanded agreement, Immunex, of Seattle, also will contribute five cancer-specific targets to the 10-target, five-year collaboration, which also calls for an equal distribution of development costs and an equal sharing of resultant candidates from the 10 targets. Some of those targets, Abgenix Chief Financial Officer Kurt Leutzinger said, could come from the CuraGen deal.

Dain Raucher Wessels analyst Andrew Milne said the Immunex deal was just the thing Abgenix investors are looking for. He called it a validation of Abgenix's program.

"This is the type of agreement we believe investors want to see Abgenix sign," Milne told BioWorld Today. "Immunex has a significant amount of experience in preclinical target validation and toxicology studies and a very strong presence in the genomics/informatics area. With all this we think they represent a marquee partner for Abgenix over the next five years.

"If you look back a few months," he continued, "to the agreement that licensed ABX-EGF to Immunex, we think Immunex took a long hard look and decided to come back to Abgenix and sign a much broader agreement. I think they're impressed with the antibody technology of Abgenix."

Immunex isn't alone in its respect for the roar of the Abgenix XenoMouse, a technology that produces fully human antibodies using transgenic mice for production. Those antibodies, the company said, avoid rejection risk by being fully human antibodies, not mouse antibodies.

CuraGen and Abgenix, now longtime partners in MAb research, expanded their already large-scale collaboration to find and commercialize 120 fully human MAbs, to include up to 250 fully human antibody therapeutic candidates.

The original deal a year ago called for research support payments from CuraGen totaling $7.5 million and an equity investment by Abgenix in CuraGen of $15 million. (See BioWorld Today, Dec.10, 1999.)

This expansion deal calls for a $50 million Abgenix investment in CuraGen, and each company expects to invest about $100 million over the life of the agreement to support research and development.

Leutzinger said the CuraGen deal is one that grew naturally from the progress of the target identification work with the New Haven, Conn.-based company.

"I think it was a mutual commitment to each other that led to this," Leutzinger said. "I think they've decided we're their antibody company, and they felt it was in their interest to get closer to us. We think it's in our interest to be closer to them, and the technology works so well together that together we'll generate a lot of product candidates."

This expansion makes for the largest antibody discovery and development collaboration in biotechnology, Milne said, and positions both companies, he added, to become the next generation of pharma company.

Abgenix has announced the discovery of 24 candidates for evaluation stemming from the alliance. Abgenix uses its proprietary XenoMouse technology to produce antibodies for CuraGen-discovered targets. (See BioWorld Today, Aug. 16, 2000.)

"It's an enormous deal, the largest antibody development deal to date," Milne said. "Abgenix and CuraGen in mid-August gave people a heads-up that they were advancing quickly and had produced 24 targets. We think that number is now over 30. Over the next several years this will turn CuraGen and Abgenix into the next generation of pharma company. What we see is the ability of Abgenix to broadly leverage an entire technology platform, and the CuraGen expansion is another validation of the antibody production capability of the XenoMouse system."

CuraGen will use its gene discovery technologies, SeqCalling, a sequence database product; PathCalling, a pathway and target discovery technology; and GeneCalling, which produces annotated and PathCalling-integrated databases, to identify targets.

Abgenix's stock (NASDAQ:ABGX) closed Tuesday at $52.375, down $7.062. Immunex's stock (NASDAQ:IMNX) fell $2.031 to close at $37.531, and Curagen's stock (NASDAQ:CRGN) rose 87.5 cents to close at $37.375.