A Japanese drug company received a broad...

A Japanese drug company received a broad U.S. patent on an anti-cancer product, interleukin-2, said Hoffmann-La Roche, the company that will market the drug exclusively in the United States. Under an agreement with Ajinomoto of Japan, La Roche said it will have the right in the United States and many other countries to exclude others from “making, using or selling” the drug. The news sparked a sharp drop in the stock of a competitor, Cetus Corp., a biotechnology company in Emeryville, Calif., that is considered the leader in developing the treatment. Cetus shares fell $1.25 to $12.50. Cetus vowed to defend its rights to the drug.