By Mary Welch

Chiron Corp. has sued Vertex Pharmaceuticals Inc. and its partner Eli Lilly and Co., claiming the two infringed Chiron's hepatitis C virus (HCV) protease patents.

Vertex, of Cambridge, Mass., and Lilly, of Indianapolis, entered a collaboration in June 1997 to develop oral inhibitors of HCV protease, an enzyme linked to growth and replication of the virus. The work is based on Vertex's small molecule drug design and identification of the 3-D structure of the target. (See BioWorld Today, June 13, 1997, p. 1.)

Chiron, of Emeryville, Calif., alleged in its U.S. District Court lawsuit the firms are in violation of Chiron's U.S. patent Nos., 5,371,017, 5,585,258, and 5,597,691.

Vertex and Lilly are among several companies working on HCV protease inhibitors. In September 1997, Chiron initiated a program to grant non-exclusive licensing rights to its HCV protease patents, which the company said cover inhibitors to the HCV NS 3 protease. Chiron is also pursuing its own research and product development activities for the disease. (See BioWorld Today, Sept. 3, 1997, p. 1.)

To date, four companies have signed non-exclusive HCV licenses, three of which were made public. They are Axys Pharmaceuticals Inc., of South San Francisco; Bristol-Myers Squibb Co., of New York; and Pharmacia & Upjohn, of London.

"I guess Vertex didn't make use of our offer, or else we wouldn't be suing them," said Jim Knighton, vice president of investor relations.

"Vertex has no comment since we have not seen nor been served with the complaint," said Andrew Marks, patent attorney for Vertex.

Chiron has been actively involved in hepatitis research since the early 1980s. Chiron scientist Michael Houghton identified the hepatitis C virus in 1989.

Chiron's stock (NASDAQ:CHIR) closed Friday at $17, down $0.75.

Vertex's shares (NASDAQ:VRTX) ended the day at $20.875, down $0.187. *