Paediatric CF trial reports positive results

Pharmaceutical company Pharmaxis (ASX:PXS) has announced positive results for its recently completed Phase II trial of Bronchitol in children and adolescents with cystic fibrosis (CF). Bronchitol is a precision spray-dried form of mannitol, delivered to the lungs by a specially designed inhaler.

The trial was a crossover design, with 6- to 17-year-old patients receiving either 400 mg of Bronchitol or a placebo for eight weeks on top of the standard of care before a washout period of eight weeks, followed by a further eight-week period on the alternate treatment. The trial was conducted across 39 centres in Belgium, Canada, France, Germany, Italy, the Netherlands, Switzerland and the UK.

During the Bronchitol treatment period, patients had a statistically significant improvement in lung function compared to the placebo, showing an absolute improvement of 3.42% in FEV₁, which equates to a relative change in FEV₁ of 4.97%. This treatment improvement in the primary endpoint occurred irrespective of whether patients were taking dornase alfa.

Secondary endpoints in the trial included absolute change in FEF_25-75, which is thought to have particular significance in younger patients. Bronchitol produced an absolute improvement of 5.75% in FEF_25-75, equating to a relative improvement of 10.5%. In other secondary endpoints, treatment-induced sputum weight was significantly increased and a positive trend was seen in FVC. Patients on Bronchitol also experienced approximately 25% fewer lung infections and exacerbations of CF.

Pharmaxis CEO Gary Phillips said the clinical trial results were “very pleasing”, especially as the trial utilised a number of different design features to overcome issues seen in the 6–17 age group in earlier phase three studies. For example, the European Medicines Agency (EMEA) agreed to the use of large particle size non-respirable mannitol as the placebo, rather than a smaller dose of the active drug; as a result, the placebo effect observed in the study was minimal.

“The young patients entered into this study were already receiving high levels of concomitant medication and had moderately impaired lung function, so the improvements shown with Bronchitol on top of this standard of care are very welcome,” said Phillips. “Crossover studies of this type are challenging, and I would like to thank everyone involved in the study for their valuable contribution.”

Pharmaxis (ASX: PXS) shares were trading 8% higher at $0.27 as of around 4.30 pm on Wednesday.