A USA based Food and Drug Administration advisory panel on Thursday said it found Gilead Sciences Inc.'s aztreonam an effective new treatment for life-threatening lung infections in cystic fibrosis patients.

Aztreonam won marketing approval in September in Europe and Canada under the brand name Cayston.

The drug is aimed at treating unceasing lung infections caused by the bacterium Pseudomonas aeruginosa. Gilead has said those lung infections are the biggest killer of people with cystic fibrosis.

The anti-infective drugs panel said that the drug was safe. The panel's opinion carries great weight even as the agency was not required to follow an advisory panel's recommendation.

Cystic fibrosis is an inherited chronic disease that affects the lungs and digestive systems of about 70,000 people worldwide, according to the Cystic Fibrosis Foundation. A defective gene and the protein it produces cause the body to produce thick, sticky mucus that clogs the lungs, leads to life-threatening lung infections and obstructs the pancreas.

Aztreonam sales could reach at least $200 million globally by 2015, according to Summer Street Research analyst Carol Werther.

Dr Bruce Marshall of the Cystic Fibrosis Foundation said there was a desperate need for additional inhaled antibiotics.

Shares of Gilead rose by 4 cents to $46.33 in after-hours trading after rising by 29 cents to close at $46.29 during the regular trading session.