Structure Of Hep C Protease Solved; On Your Marks]

As biotechnology companies with a key interest in virology, Agouron and Vertex have a lot in common. But even more so last week, as the two firms simultaneously published the three-dimensional atomic structure of hepatitis C virus' NS3 protease, determined by X-ray crystallography. Both papers are published in the October 18 issue of the journal Cell.

Vertex reported some details of the structure at this year's International Conference on Antimicrobial Agents and Chemotherapy (Marketletter October 7), and both companies are now engaged in a race to develop new inhibitors for HCV. As is usual in these cases, they have reported enough of the detail of the structure to satisfy the demands of peer-review publication, but have left out certain elements that may be helpful to competitors.

There is a desperate need for new drug treatments for HCV, as the only approved drug, interferon alpha, achieves an extremely low rate of viral clearance, with durable responses seen in only 15% of patients or lower. Approaches in drug discovery used to date, such as high-throughput screening of chemical libraries, have yielded little apparent progress. HCV is thought to infect more than 1% of the US population, and is associated with a high rate of persistent, carrier states (70%-85%).