Corvas International Inc. said that it has exclusive rights to a newly issued patentfor human tissue factor.

U.S. patent No. 5,110,730, which claims the DNA molecule for human tissue factor andthe method of preparing it, issued Tuesday to The Scripps Research Institute of La Jolla,Calif.

San Diego-based Corvas (NASDAQ:CVAS) is in advanced development of a diagnostic productusing the factor to determine the blood clotting capability of patients. Because Corvas isfocused on therapeutics, the company intends to license out the technology to adiagnostics company, said John Crawford, chief financial officer.

More than 500 million such tests are performed annually worldwide.

Because existing tests use non-human material, they do not provide consistentlyaccurate and reproducible results, the company said. Corvas shares rose 38 cents to $7.63on Thursday.