By Marilyn Bitomsky
BRISBANE, Australia (Reuters Health) – Drugs to prevent or treat cystic fibrosis (CF) are being developed by researchers at the University of North Carolina at Chapel Hill.
Presenting promising early results at the Fourth Australian and New Zealand Cystic Fibrosis conference, chemistry professor Dr. Michael Knowles explained that a gene mutation in CF leads to thick airway secretions, which is somehow linked to abnormal high-end transport of salt and water across the airways.
"The problem in CF is that there is too little water in the mucus," he said. "We are trying to develop drugs to block the reabsorption of salt in water, specifically focusing on derivatives of amiloride."
Amiloride is effective in the short term, for a few doses over a few weeks, but not over the long term, so the goal is to develop longer-acting forms of this drug.
P2Y2 agonists, which activate chloride channels in the airways to cause liquid secretion, are also being tested, Dr. Knowles reported.
Phase I studies of P2Y2 agonists in 96 CF patients, both adults and children, have been completed, said Dr. Knowles. "These drugs are tolerated [in the short term], but we don't have any hard data yet to show they will be effective in the long term."
Dr. Knowles also said that pediatric patients have a better response because their baseline lung function is usually better.
"It is likely that we will enter into phase II studies in 2003." He added that if the drugs appear useful in those studies, it is possible that they will be available commercially 2 years later.