Gilead Sciences, Inc announced that the European Commission has granted conditional marketing authorization for Cayston 75 mg powder and solvent for nebuliser solution (aztreonam lysine) for the suppressive therapy of chronic pulmonary infections due to Pseudomonas aeruginosa (P. aeruginosa) in patients with cystic fibrosis (CF) aged 18 years and older. Cayston will be made available in certain countries of the European Union, subject to the requirements of national authorities, beginning in early 2010.

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 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.

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.

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.