Creative BioMolecules Inc. announced Thursday that it hasreceived a U.S. patent on the use of platelet derived growthfactor (PDGF) for treating gastrointestinal ulcers.

The patent, No. 5,234,908, was jointly issued to Brigham andWomen's Hospital in Boston, which collaborated with CreativeBioMolecules on the underlying research. "We both own thepatent," explained Wayne Mayhew III, vice president and chieffinancial officer of Creative BioMolecules. "We have to license itfrom each other to use it."

Platelet-derived growth factor is a potent growth stimulator.It's a naturally occurring peptide hormone that influences thebody's wound-repair process by triggering an influx ofinflammatory and repair cells into the site of damage. It'sbelieved that PDGF stimulates DNA synthesis by those cells,causing them to proliferate, thus accelerating the deposition ofnew scaffolding for tissue regeneration.

Creative BioMolecules (NASDAQ:CBMI) of Hopkinton, Mass., nowhas patent coverage on using PDGF for treating ulcers presentin the ileum and colon, and peptic ulcers of the duodenum,stomach and esophagus.

The company presented preclinical data in May at theAmerican Gastroenterological Association meeting on PDGF'shealing abilities in duodenal ulcers, showing that PDGFaccelerated healing of the gastrointestinal lesions, completelyrestored the normal mucosal tissue. PDGF had no effect on thenormal function of the gastrointestinal tract.

Creative BioMolecules holds a second use patent, No. 5,149,691,issued in September 1992, on PDGF for treating periodontaldisease (in combination with dexamethazone), said a companyscientist. The company reported at an FDA workshop preclinicaldata in April demonstrating that its PDGF significantlyregenerates periodontal tissue in 88 percent of the primatestested.

The company has applied for a patent for its own method ofproducing PDGF, but it hasn't issued yet, according to acompany spokesman.

Chiron Corp. (NASDAQ:CHIR) of Emeryville, Calif., and AmgenInc. (NASDAQ:AMGN) of Thousand Oaks, Calif., are alsodeveloping therapeutic applications for PDGF, and bothcompanies have patent positions.

Although the natural molecule can't be patented per se, thereare purified versions, analogs, variations (the PDGF moleculeconsists of two amino acid chains, termed alpha and beta; thisin itself allows for a certain number of permutations) andmethods of manufacture (processes) to be considered.

Chiron's PDGF for treating skin ulcers in diabetic patients is inPhase II trials under the sponsorship of the Robert WoodJohnson Research Institute (the R&D arm of Johnson &Johnson).

Chiron has applied for patents on the production of PDGF, itsuses and various formulations.

Amgen's version of PDGF is in Phase II clinical trials fortreating bedsores, which are chronic non-healing wounds thatcan even lead to death. Last spring, however, the companydecided to discontinue the clinical development of that PDGFbecause of lack of sufficient efficacy. Nonetheless, Amgen willcomplete the trials, according to Kimberly Dorsey, Amgen'sassociate manager of corporate communications.

The company has an issued U.S. composition-of-matter patenton its version of PDGF, Dorsey added.

And ZymoGenetics Inc. a wholly owned subsidiary of Novo-Nordisk, has "a number of issued patents in the U.S. coveringPDGF, both composition-of-matter and methods of production,"explained Mark Murray, director of new business developmentat the Seattle company.

-- Jennifer Van Brunt Senior Editor

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