By Matthew Willett

Corixa Corp. entered an agreement with Purdue BioPharma L.P. to develop novel therapeutic antibodies against cancer based on tumor surface antigen targets, a deal that provides the pharma company with antigens isolated by Corixa.

Purdue, a subsidiary of Norwalk, Conn.-based Purdue Pharma, will provide Corixa with guaranteed research funding for up to four therapeutic antibodies to be targeted using Purdue's Synthebody antibody engineering platform. Corixa also holds the option to license resultant targets to Purdue for development for up-front fees, milestone payments and royalties.

The agreement is a two-year collaboration with multiple renewal opportunities.

Corixa CEO Steven Gillis said Purdue found Corixa and expressed interest in the company's antigens.

"I think their interest was in taking advantage of some of the antibody technology they've developed over the years and attempting to get into the area of oncology," Gillis said. "And I think they felt that we had distinguished ourselves as one of the premier antigen discovery companies, and as a result of that they started talks with us on a collaboration."

Corixa will provide Purdue with antigens from its discovery pipeline for development into synthesized human antibodies. Corixa will maintain rights to those antigens and to any antibodies produced by Purdue, but agreed to license antibodies and targets to Purdue for up-front fees, milestone payments and royalties negotiated in the collaborative agreement.

The antigens Corixa will provide Purdue are cell-surface proteins overexpressed in cancer cells. Their functions currently are unknown. Purdue kept an option to develop small molecules that might interact with antigen targets to mediate an antitumor effect.

Seattle-based Corixa focuses on cancer and autoimmune disease vaccines and immunotherapeutics, monoclonal antibody-based therapeutics and diagnostics and delivery systems and adjuvants designed to increase vaccine and immunotherapeutic effectiveness.

Since foundation in 1994, Corixa has developed core technologies in antigen discovery through mapping patient immune responses and isolating pathogen or tumor genes that encode immune system response-generating antigens. Corixa then formulates those antigens as recombinant protein or biosynthetically produced peptide microspheres.

The company currently partners with 35 companies for vaccine programs, Gillis said, including multiple-target collaborations with SmithKline Beecham plc, of London, for tuberculosis, prostate, ovarian, and colon cancer research; Schering Plough Corp. of Madison, N.J., for a melanoma vaccine in Phase III testing; and Biomira Inc., of Edmonton, Alberta, for the Detox adjuvant, which also is in Phase III.

In addition to those collaborations, Corixa joined with Princeton, N.J.-based Medarex Inc. in June to develop fully human monoclonal antibodies. Corixa entered a similar agreement with Abgenix Inc., of Fremont, Calif., in March. (See BioWorld Today, June 8, 2000, p. 1.)

Gillis said the agreement with Purdue is one Corixa would like to see duplicated in the future.

"We wholeheartedly embrace this as an opportunity to continue to leverage value from our primary focus of developing antigen vaccines," he said.

Thomas Dietz of Pacific Growth Equities reiterated his buy rating for Corixa on the news. "This deal represents yet another potentially lucrative collaboration in which Corixa's portfolio of antigens are being exploited for the development of antibodies and potentially small-molecule drugs," Dietz said in a research note.

Corixa shares (NASDAQ:CRXA) rose 31.25 cents Monday to close at $49.44.