FDA panel backs tobramycin inhalation powder for patients with cystic fibrosis

An FDA advisory panel voted 13 to 1 that there was adequate evidence of efficacy and safety to support the use of tobramycin inhalation powder (TIP) (Novartis) for the management of cystic fibrosis (CF) patients whose lungs contain bacteria called Pseudomonas aeruginosa (Pa). Pa is the leading cause of loss of lung function in people with CF. TIP is intended for use in CF patients aged 6 years and older whose lung function is within a certain range (ie, FEV₁ between 25% and 80% predicted).

The Anti-Infective Drugs Advisory Committee (AIDAC) based its recommendation on 3 phase 3 clinical studies involving more than 650 CF patients aged 6 years and older, of whom 425 patients received at least 1 dose of TIP. The studies found that treatment with TIP resulted in improved lung function.

"While advances in research and medical treatments have substantially enhanced and extended the lives of patients with CF, the treatment burden remains very high," TIP clinical investigator Michael Konstan, MD, chairman of the department of pediatrics and director of the Cystic Fibrosis Center at Rainbow Babies and Children's Hospital and Case Western Reserve University School of Medicine in Cleveland, Ohio, said in a Novartis press release.

Tobramycin is currently marketed in the United States by Novartis as TOBI (tobramycin inhalation solution, USP), and is administered as a nebulized solution with an indication similar to that proposed for TIP. In contrast, investigational TIP is a new inhaled formulation of tobramycin consisting of dry powder in capsules delivered via a dry powder inhaler. The new formulation was developed using proprietary Novartis PulmoSphere technology. This enabled the creation of hollow porous particles of tobramycin that can be delivered as a dry powder rather than as a nebulized solution.

According to the Cystic Fibrosis Foundation, cystic fibrosis is an inherited chronic disease that affects the lungs and digestive system of about 30,000 children and adults in the United States (70,000 worldwide). The treatment burden for CF is extremely high, with as many as 20 medications having to be used every day with a combined average treatment time of 108 minutes. The overall time to administer all the necessary treatments and perform physiotherapy and exercise can be as much as 2 to 3 hours each day.

If patients are allergic to antibiotics in the same family as TOBI (ie, aminoglycosides), they should not take TOBI. They should tell their doctor before starting treatment if they have any history of hearing, kidney, balance, or muscle problems.

Patients taking TOBI may have temporary side effects like coughing or difficulty breathing. Some people taking TOBI experienced ringing in the ears, hearing loss, or changes in voice (hoarseness).

In studies, kidney damage was not seen in patients taking TOBI. However, antibiotics in the same family as TOBI have been linked to kidney damage.

If patients are pregnant, plan to become pregnant, or if they are breast-feeding, they should talk with their doctor before taking TOBI.

Some drugs may interact with TOBI. Patients should discuss all medications they are taking with their doctor.