FDA Approves Inhaled Aztreonam for Cystic Fibrosis
By Yael Waknine
Medscape Medical News
February 24, 2010 — The US Food and Drug Administration (FDA) has approved aztreonam inhalation solution (Cayston, Gilead Sciences, Inc) to improve respiratory symptoms in patients with cystic fibrosis (CF) with Pseudomonas aeruginosa. The product is expected to be available in specialty pharmacies by the end of next week.
P aeruginosa colonization occurs in about 90% of patients with CF at some point during their lives and is an important contributor to the vicious cycle of infection and inflammation leading to bronchiectasis and eventual respiratory failure.
As the first new inhaled antibiotic to be approved for CF patients in more than a decade, aztreonam represents a much-needed therapeutic alternative for CF patients who have developed resistance to current therapies.
"We are delighted to have a new antibiotic in the arsenal to help fight the life-threatening infections associated with this disease, as we continue to push forward with other therapies that address the underlying cause of CF," said Robert J. Beall, PhD, president and chief executive officer of the Cystic Fibrosis Foundation, in a news release. The foundation invested $1 million in helping develop the therapy.
Aztreonam inhalation solution is administered as a 75-mg dose 3 times daily during a 28-day period. The antibiotic is delivered via a drug-specific portable nebulizer system (Altera, PARI Pharma GmbH) that uses proprietary eFlow technology to deliver each dose in less than 3 minutes, thereby reducing the burden for CF patients who often require 3 to 4 hours of treatment daily.
The product's approval was based on data from a 28-day study of 164 patients aged 7 years and older with forced expiratory volume in 1 second (FEV1) of 25% to 75% predicted (mean, 55%), who were randomly assigned to receive either 75 mg aztreonam inhalation solution or placebo 3 times daily, in addition to standard CF care.
Results on the last day of treatment showed that aztreonam significantly improved respiratory symptoms from baseline relative to placebo; mean improvements were substantially greater for pediatric compared with adult patients.
Pulmonary function was also significantly improved in aztreonam-treated patients relative to placebo (FEV1 treatment difference, 10%; 95% confidence interval [CI], 6% - 14%), and no differences were noted between adult and pediatric patients.
Two weeks after completion of therapy, a smaller difference in respiratory symptoms between treatment groups remained and the difference in FEV1 had decreased to 6% (95% CI, 2% - 9%).
Adverse events most commonly associated with aztreonam therapy (prevalence > 5%) included cough, nasal congestion, wheezing, pharyngolaryngeal pain, pyrexia, chest discomfort, abdominal pain, and vomiting.
To support patients, the company is launching a call center that was developed with a nonprofit subsidiary of the Cystic Fibrosis Foundation. The Cayston Access Program will assist people with CF and members of their care team with insurance verification, copay assistance, and claims support. Additional information is available online on the program's Web site or by calling 1-877-7CAYSTON begin_of_the_skype_highlighting
