Gilead Sciences has exercised its option to purchase Corus Pharma for $365 million. The transaction is expected to close in the third quarter of this year, subject to clearance under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. In April 2006, Gilead invested $25 million in Corus, becoming the second largest shareholder in the company and gaining an exclusive option to purchase the remaining shares of the company. Corus’ lead product candidate, aztreonam lysine for in...