Gilead Sciences Exercises Option to Acquire Corus Pharma for $365 Million

FOSTER CITY, Calif. & SEATTLE--(BUSINESS WIRE)--Aug. 2, 2006--Gilead Sciences, Inc. (Nasdaq:GILD) today announced that the company has exercised its option to purchase privately-held Corus Pharma for $365 million. The transaction is expected to close in the third quarter, subject to clearance under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, and is expected to be dilutive to Gilead's 2006 and 2007 earnings.

On July 19, Gilead notified Corus of its intention to exercise its option to acquire the company. 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 inhalation, is an inhaled antibiotic with activity against Gram-negative bacteria including Pseudomonas aeruginosa, which can cause lung infections in patients with cystic fibrosis (CF). Phase III studies to evaluate the product as a potential treatment for CF-related pulmonary infections are currently enrolling. In addition to aztreonam lysine, Corus is exploring an inhalation formulation of two antibiotics for the potential treatment of respiratory infections. This program is currently in preclinical development. The company is also exploring treatments for other respiratory diseases such as chronic cough and asthma.

"Cystic fibrosis represents an important area of unmet medical need and the early exercise of this option underscores the potential therapeutic advancement we believe aztreonam lysine represents for patients," said John F. Milligan, PhD, Executive Vice President and Chief Financial Officer, Gilead Sciences. "We intend to retain Corus' Seattle-based operations, and we look forward to welcoming the Corus employees to Gilead and to working together to advance the development of aztreonam lysine."

"We are excited to partner our efforts with a company that has demonstrated expertise and success in developing and commercializing novel products for infectious diseases, and whose leadership underscores the difference we can make for patients and physicians," said A. Bruce Montgomery, MD, Chief Executive Officer of Corus. "The completion of this transaction will help Corus more rapidly develop aztreonam lysine and will fuel additional progress across our research pipeline."

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company's mission is to advance the care of patients suffering from life-threatening diseases worldwide. Headquartered in Foster City, California, Gilead has operations in North America, Europe and Australia. For more information on Gilead Sciences, please visit the company's website at www.gilead.com or call Gilead Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.

About Corus Pharma

Corus Pharma is committed to developing and commercializing specialty products for respiratory and infectious diseases that can help provide improved health and superior quality of life. Corus is a privately-held, venture capital backed company whose investors include Bear Stearns Health Innoventures, Burrill & Company, JPMorgan Partners (now known as Panorama Capital), Novo A/S, Orbimed Advisors and others. More information about Corus Pharma may be found at www.coruspharma.com.

This press release includes forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995, that are subject to risks, uncertainties and other factors including the risks to both companies that the acquisition of Corus will not be consummated as the transaction is subject to certain closing conditions. In addition, if and when the transaction is consummated, there will be risks and uncertainties related to our ability to successfully integrate the products and employees of Gilead and Corus and the ability of aztreonam lysine for inhalation to receive regulatory approvals or market acceptance. These risks, uncertainties and other factors could cause actual results to differ materially from those referred to in the forward-looking statements. The reader is cautioned not to rely on these forward-looking statements. These and other risks are described in detail in Gilead's Annual Report on Form 10-K for the year ended December 31, 2005, Quarterly Report on Form 10-Q for the first quarter of 2006 and subsequent current reports on Form 8-K as filed with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to Gilead and Gilead assumes no obligation to update any such forward-looking statements.

CONTACT: Gilead Sciences Susan Hubbard, 650-522-5715 (Investors) Erin Edgley, 650-522-5635 (Media) or Corus Pharma Guy Seaton, 206-728-5090 or Dave Syferd and Partners (for Corus) Laurie Christomos, 206-262-0395 SOURCE: Gilead Sciences, Inc.