Swiss drug maker company Roche Holding AG says it is buying San Diego-based Anadys Pharmaceuticals Inc. for $230 million.
Roche says it will pay $3.70 per share, a premium of more than 250 percent on Anadys's closing price Friday.
Roche said in a statement Monday that the acquisition would boost its portfolio of drugs to treat hepatitis C.
Anadys has developed an oral drug called Setrobuvir that is currently being trialed for treatment of chronic hepatitis C infections.
Roche last week reported third-quarter sales of 9.82 billion Swiss francs ($10.98).