BioWorld International Correspondent

PARIS - French gene profiling company ExonHit Therapeutics SA signed a research contract with Roche Applied Science for the development of tests to diagnose bovine spongiform encephalopathy in living animals.

The collaboration will bring together Penzberg, Germany-based Roche's PCR-workflow diagnostics platform and ExonHit's qualitative gene profiling technology, DATAS, to identify RNA signatures in bovine blood correlating to BSE infection. The signatures will be used to develop a test for BSE (otherwise known as mad cow's disease) on live cattle.

The companies expect to develop the test within 12 months, and in the first instance will make it available to third parties for research and evaluation purposes. ExonHit's CEO, Bruno Tocqué, told BioWorld International that Roche would pay ExonHit for its services and that once the test is developed, the companies would negotiate a licensing agreement under which Roche would commercialize the product and ExonHit would receive royalties.

The value of the deal would depend on the test's commercial potential, Tocqué said. Not only are there millions of cattle to be tested, but the product also could be used to test sheep flocks, and could be extended to other prion-based diseases, such as scrapie. He added that ExonHit had been looking for an opportunity to collaborate on diagnostics for prion-based pathologies and hopes the deal with Roche would be "a first step that leads to others."

Roche Applied Science is a branch of Roche Diagnostics, a division of the Swiss pharmaceutical company F. Hoffmann-La Roche Ltd., of Basel, Switzerland.

ExonHit's DATAS (differential analysis of transcripts with alternative splicing) technology detects disease-relevant changes in mRNA sequences resulting from alternative RNA splicing, and can be used to characterize and systematically compare RNA splicing alterations that occur in the progression of a disease. RNA splicing occurs after gene transcription (the reading of the gene's information) and before protein is produced in accordance with the gene's information (protein translation). ExonHit said alternative splicing could be responsible for generating up to three times as many proteins as there are genes in the human genome - around 30,000 at the latest estimate.

The Paris-based company's most recent research collaboration agreement was signed in January with IDEC Pharmaceuticals Corp., of San Diego, for the discovery of new antigen targets for antibody therapy, with a particular focus on prostate carcinoma. It also was ExonHit's first deal with a U.S. company, and developing its activities in North America is now a priority for the company. To that end, it opened a regional research and development center in Gaithersburg, Md., in April, which is focusing on new therapeutic fields such as monoclonal antibodies, vaccines, small-molecule drugs and blood-based diagnostics. ExonHit plans to use it as a springboard to gain access to local scientific expertise and to negotiate more collaborations with North American companies.