Cor Therapeutics Inc. is about to receive an exclusive license tothe platelet-derived growth factor (PDGF) receptor gene fromthe National Institutes of Health's Office of TechnologyTransfer.

Today is the cutoff date on a 60-day public comment period forthe licensing opportunity, announced in the Federal Register onJan. 27. It states that the Office of Technology Transfer "iscontemplating the grant of an exclusive worldwide license topractice the invention, entitled 'Alpha Platelet-Derived GrowthFactor Receptor Gene,' to Cor Therapeutics Inc. of South SanFrancisco, Calif."

Cor had approached NIH to acquire access to the receptor geneprimarily because of its potential application to cardiovasculardisease, the company's vice president of corporatedevelopment, R. Lee Douglas Jr., told BioWorld.

The principal inventor of the patent-pending alpha PDGFreceptor gene is cell biologist Stuart Aaronson, who heads theNational Cancer Institute's cellular and molecular biologylaboratory. PDGF he explained, is a ligand thought to play animportant role in stimulating overgrowth of smooth-musclecells in arteries that re-stenose after being scraped byangioplasty, or wounded by coronary bypass surgery.

"The market for restenosis includes about 350,000angioplasties and 380,000 coronary bypass surgeries each yearin the U.S. alone, " wrote Brandon Fradd of MontgomerySecurities in San Francisco in a financial analysis of Cor.

Restenosis occurs in 30 percent of angioplasty patients. "ThePDFG transmembrane receptor," Aaronson told BioWorld, "canprovide an antagonist to the platelet growth factor." Hecompared this strategy with deploying the CD4 receptor toblock the AIDS virus.

There are, in fact, two classes of PDGF receptor, alpha and beta,Douglas pointed out, and three types of the PDGF ligand protein.A Cor co-founder, Lewis T. Williams of the University ofCalifornia School of Medicine, discovered the beta receptor,which binds to two of the three PDGF molecular variants.Aaronson identified and cloned the alpha version, which reactswith all three.

Its potential therapeutic uses, Aaronson told BioWorld, extendbeyond the cardiovascular to "any place or time in whichabnormal production of the PDGF protein, and overstimulationof its target cells, lead to abnormal proliferation."

One example he cites is arthritis, "where joints become hurt bythe overproduction of connective-tissue cells." Cancer isanother. "In some brain tumors, the receptor is amplified andthe protein overexpressed, so one could envisage a radioisotopeor cytotoxin linked to antibodies or to the ligand itself, homingin on and maybe destroying tumor cells overexpressed by thereceptor."

Aaronson also emphasizes the receptor's longer-term potentialin screening for small-molecule drugs capable -- in a morepharmacologically useful form -- of mimicking the growthfactor or its receptor.

The technology-transfer offer stipulates that "if the prospectiveexclusive license is granted to Cor Therapeutics, licenses for theuse of the PDGF receptor for internal research purposes or itssale as a research reagent would still be available from theNIH."

"We are pleased to have the opportunity to obtain this license,"said Douglas, "because of our interest in this field, and itspotential for a number of cardiovascular applications, includingrestenosis."

Cor's stock (NASDAQ:CORR) closed unchanged Friday at $9.50 ashare.

-- David N. Leff Science Editor

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