Enzon Inc. and Oncologix Inc. announced Tuesday that theyhave agreed to cross-license patents that will allow thedevelopment of new cancer therapies.

Enzon's patent concerns its single-chain antigen-binding (SCA)proteins, while Oncologix's relates to an erbB-2 monoclonalantibody.

Under the terms of the agreement, Enzon of Piscataway, N.J.,will receive non-exclusive rights to certain of Oncologix'smonoclonal antibodies that recognize and target the erbB-2tumor marker. Enzon (NASDAQ:ENZN) intends to develop anti-cancer therapies based on targeting this marker with SCAproteins, which are designed to have greater tumor penetrationand localization than monoclonal antibodies.

Oncologix, a development-stage company based inGaithersburg, Md., will receive worldwide exclusive rights toapply the SCA protein technology to its ReT-9 compound, agenetically engineered anti-tumor toxin designed to target anddestroy cancer cells that overexpress the erbB-2 oncogene.

Enzon will receive an initial payment, milestone payments androyalties on Oncologix's product sales, while Oncologix willreceive milestone payments and royalties if Enzoncommercializes products based on the erbB-2 monoclonals.

Oncologix was started in 1987 by Healthcare Investment Corp."with a singular focus on cancer," explained Charles Blitzer, itspresident and chief executive officer. The company alreadyoffers a cancer testing service and diagnostic reference lab tooncologists through its subsidiary Molecular Oncology Inc.

For developing therapeutics, Blitzer said, the company has itsown in-house research, which it will fuel with cash generatedfrom oncology compounds in-licensed from largepharmaceutical houses.

Oncologix's lead compound, ReT-9, is a toxin linked -- notconjugated -- to an SCA. The toxin moiety is a 40,000 molecularweight Pseudomonas exotoxin that has been modifiedchemically, Blitzer explained. It's specific for tumors thatexpress the erbB-2 oncogene. "When ReT-9 is internalized bythe target cell, the toxin is released. It's the toxin that does thekilling and the cell shrinkage," Blitzer told BioWorld. He addedthat company researchers have already demonstrated thatReT-9 reproducibly shrinks gastric tumors in nude mice, andthat it's not toxic in rats. The compound is currently inprimates, and Oncologix could be ready to start Phase I humanclinical trials by mid-1994, Blitzer told BioWorld.

Enzon inherited the SCA technology as part of its acquisition ofGenex Corp. in October 1991. Enzon also is "negotiating the finalagreements for cross-licensing" with Creative Biomolecules Inc.of Hopkinton, Mass., which has developed a similar technologybased on biosynthetic antibody binding (BAB) proteins,explained R. Douglas Hulse, Enzon's vice president of businessdevelopment.

Enzon has already granted non-exclusive licenses to its SCAtechnology to Neoprobe Corp., Hybritech Inc., BaxterInternational Inc. and Pharmacia. Neoprobe of Columbus, Ohio,licensed the technology in August 1992 for use in itsradioimmunoguided surgery for detecting breast and othercancers.

Hybritech, an Eli Lilly and Co. subsidiary, licensed thetechnology in December '92 , several days after Enzon granteda non-exclusive license to Baxter to use the SCA technology inits cancer research programs focusing on human stem cellisolation and gene therapy. And Pharmacia licensed thetechnology in Sept. '92 to develop research kits to screen forSCAs, Hulse told BioWorld.

-- Jennifer Van Brunt Senior Editor

(c) 1997 American Health Consultants. All rights reserved.