Because some drug targets are particularly attractive, it's not uncommon for biotech companies working in similar areas to announce similar discoveries at the same time. Last week scientists from Agouron Pharmaceuticals Inc. (AGPH, La Jolla, Calif.) and Vertex Pharmaceuticals Inc. (VRTX, Cambridge, Mass.) published separate papers in Cell describing the three-dimensional structure of the hepatitis C virus's NS3 protease enzyme.

Because NS3 protease plays an important role in viral replication similar to that of HIV protease, for which several successful drugs have been developed, it represents an attractive therapeutic target.