Press Releases

September 23, 2009

European Commission Grants Conditional Marketing Authorization to Cayston(R) (Aztreonam Lysine) for the Treatment of Chronic Pulmonary Infections Due to Pseudomonas Aeruginosa in Patients with Cystic Fibrosis

CF is a chronic, debilitating genetic disease that affects the respiratory and digestive systems of approximately 70,000 people worldwide, including 35,000 people in the European Union. Chronic pulmonary infections due to P. aeruginosa are the single greatest cause of morbidity and mortality among patients with CF.

Cayston is an inhaled antibiotic that is dosed three times per day over a 28-day period. Cayston is delivered via the Altera^(R) Nebuliser System, a drug-specific delivery device from the eFlow^(R) Technology Platform, developed by PARI Pharma GmbH. PARI Pharma also contributed to the development of Cayston's drug formulation for delivery with the Altera Nebuliser System.

"Cayston is an important addition to the fight against infection in people with cystic fibrosis, and its approval will bring a further treatment option to patients suffering from this debilitating disease," said Stuart Elborn, Professor of Respiratory Medicine, Queens University of Belfast. "The cystic fibrosis community is very pleased that the EMEA has recognized the importance of bringing forward this effective new treatment."

The approval of Cayston is based on the results of two Phase III, single-course, placebo-controlled clinical studies (CP-AI-007 and CP-AI-005) and the results of an open-label, multiple-course extension study (CP-AI-006) of patients who participated in CP-AI-007 or CP-AI-005.

Conditional marketing authorizations are granted to products that address unmet medical needs and whose availability would result in a significant public health benefit. Consideration for full marketing authorization is contingent upon the completion of an additional ongoing Phase III study examining the efficacy and safety of Cayston compared to tobramycin nebuliser solution in CF patients with pulmonary P. aeruginosa.

Applications for marketing approval of Cayston are currently pending in Australia, Switzerland and Turkey. In September 2009, Cayston was approved in Canada. Earlier this year, the United States Food and Drug Administration (FDA) requested that Gilead conduct an additional clinical study before resubmitting its New Drug Application. In the United States, Cayston remains an investigational compound that has not yet been approved for use.

About Cayston

Cayston (aztreonam lysine 75 mg powder and solvent for nebuliser solution) is an inhaled antibiotic for the suppressive therapy of chronic pulmonary infections due to P. aeruginosa in patients with CF aged 18 years and older. Cayston has potent in vitro activity against Gram-negative bacteria such as P. aeruginosa. Aztreonam formulated with arginine is an approved agent for intravenous administration for treating various infections. Aztreonam lysine is a proprietary formulation of aztreonam developed specifically for inhalation. It has been designated with orphan drug status in the United States and Europe.

Cayston is for inhalation use only, and patients should use a bronchodilator before each dose of the medication. Dosing is three times per day over a 28-day treatment course, with doses taken at least four hours apart. Additional courses should be considered only at the discretion of the physician, and at least a 28-day off period between courses is recommended.

About the Altera Nebuliser System and eFlow Technology

Cayston is delivered via the Altera Nebuliser System, an inhalation delivery device optimized specifically for Cayston. Altera Nebuliser Systems are consistent with the specifications of the customized eFlow Nebuliser System used exclusively in all Cayston clinical trials. The Altera Nebuliser System uses eFlow Technology to enable highly efficient aerosolization of medication via a vibrating, perforated membrane that includes thousands of small holes to produce the aerosol mist. Compared to other nebulization technologies, eFlow Technology produces aerosols with a very high density of active drug, a precisely defined droplet size, and a high proportion of respirable droplets delivered in the shortest possible period of time. Combined with its quiet mode of operation, small size (it fits in the palm of the patient's hand), light weight, and battery use, eFlow Technology reduces the burden of taking daily, inhaled treatments. The Altera Nebuliser System and eFlow Technology are proprietary to PARI Pharma.

Important Safety Information

Cayston is not recommended for use in children below the age of 18 years due to insufficient data on safety and efficacy.

Cayston should only be reconstituted with the solvent provided and it is recommended that Cayston be administered immediately after reconstitution with solvent. Cayston is only to be used with the Altera Nebuliser System or with the Altera Nebuliser Handset (including the Altera Aerosol Head) connected to a universal eFlow Technology controller (e.g. eBase Controller or eFlow(R)rapid Control Unit).

Aztreonam for injection must not be used in the Altera Nebuliser System or any other nebuliser.

If an allergic reaction to Cayston occurs, stop administration of the medicinal product and initiate treatment as appropriate. Cross-reactivity may occur in patients with a history of allergy to beta-lactam antibiotics, such as penicillins, cephalosporins, and/or carbapenems. Caution is advised when administering Cayston to patients if they have a history of beta-lactam allergy.

The following rare and severe adverse reactions, although these have not been observed to date with Cayston, have been reported after parenteral use of other aztreonam containing products: toxic epidermal necrolysis, anaphylaxis, purpura, erythema multiforme, exfoliative dermatitis, urticaria, petechiae, pruritus and diaphoresis. Bronchospasm is a complication associated with nebulised therapies. Patients should use a bronchodilator before each dose of Cayston. If a case of bronchospasm is suspected to be part of an allergic reaction appropriate measures should be taken.

The development of antibiotic-resistant P. aeruginosa and superinfection with other pathogens represent potential risks associated with antibiotic therapy. Development of resistance during inhaled aztreonam therapy could limit treatment options during acute exacerbations.

The adverse reactions with suspected (at least possible) relationship to treatment in the placebo-controlled studies are as follows: very common - wheezing, cough, pharyngolaryngeal pain, nasal congestion and pyrexia; common - non-allergic bronchospasm, chest discomfort, rhinorrhoea and rash.

For full prescribing information, please consult the European Summary of Product Characteristics (SmPC).

About PARI Pharma

PARI Pharma focuses on the development of aerosol delivery devices and comprehensive inhalation drug development to advance aerosol therapies where drug and device can be optimized together. Based on PARI's 100-year history working with aerosols, PARI Pharma develops treatments for pulmonary and nasal administration customized with advanced delivery platforms, such as eFlow (lower respiratory) and Vibrent (upper respiratory) Technologies. PARI Pharma partners with pharmaceutical companies to develop new or improved therapies. PARI Pharma has several clinical development programs ongoing, either partnered or on its own, for cystic fibrosis, asthma, COPD, respiratory syncytial virus (RSV) infection, and treatments for lung transplant patients among other indications. More information is available at www.paripharma.com.

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.

Forward-Looking Statement

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 related to Gilead's ability to complete the additional ongoing Phase III study of Cayston required by the European Commission. For example, safety issues may arise or the results from the clinical study may be otherwise inadequate to support regulatory approval of Cayston. As a result, full marketing authorization for Cayston may not be obtained. Further, Gilead may not obtain marketing approval of Cayston in the United States, Australia, Switzerland and Turkey, where new drug applications are pending. For example, existing data from ongoing clinical trials or any additional clinical trial that we may commence to satisfy any regulatory authorities' concerns may not support the approval of Cayston in such countries, which may cause us considerable expense and may lead to further delays or cause us to abandon further development of the product in such countries, including the United States. 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 Quarterly Report on Form 10-Q for the first and second quarters of 2009, 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.

Cayston is a registered trademark of Gilead Sciences, Inc.

For more information on Gilead, please call the Gilead Public Affairs Department at 1-800-GILEAD-5 (1-800-445-3235) or visit www.gilead.com.

In Europe, for medical information about Cayston or to obtain the European Summary of Product Characteristics, please contact Gilead's EU Medical Information department at intlmed.info@gilead.com.

SOURCE: Gilead Sciences, Inc.

Gilead Sciences, Inc.
Susan Hubbard, Investors, 650-522-5715
James Read, Media (Europe), +44(0)208 587 2323
Amy Flood, Media (U.S.), 650-522-5643