Patients receiving Cayston had an adjusted mean actual increase in FEV percent predicted from baseline over six months of 2.05% compared to a 0.66% decrease for patients receiving TIS.
Gilead Sciences said that the first co-primary endpoint of non-inferiority for mean percent change in FEV1 percent predicted at Day 28 was also achieved and Cayston met the statistical definition of superiority.
In the study, 268 patients were randomised to receive 28-day intermittent repeating courses of Cayston (75mg three times daily) via the Altera Nebulizer System (PARI Pharma) or TIS (300mg twice daily) via the PARI LC Plus Nebulizer over a 24-week treatment period.
Baylor College of Medicine, Houston, Texas Cystic Fibrosis Care Center director and Pediatrics associate professor Christopher Oermann said that the results of this trial demonstrate that Cayston is effective across three treatment cycles in improving lung function and respiratory symptom scores.
"Cayston is an important new therapy for the treatment of pseudomonal airway infection in people living with cystic fibrosis," Oermann said.
Cayston was approved by the US Food and Drug Administration and the Australian Therapeutic Goods Administration in 2010 and received conditional marketing authorisations in the EU and Canada in September 2009.