PTC124 for Cystic Fibrosis

In this study, patients with CF due to a nonsense mutation will be treated with a new investigational drug called PTC124. Evaluation procedures (history, physical examination, blood and urine tests to assess organ function, electrocardiogram (ECG), chest x-ray, and CF-specific tests) to determine if a patient qualifies for the study will be performed within 21 days prior to the start of treatment. Eligible patients who elect to enroll in the study will then participate in two 28-day treatment and follow-up periods (56 days total). Within the first 28-day period, PTC124 treatment will be taken 3 times per day with meals for 14 days at doses of 4 mg/kg (breakfast), 4 mg/kg (lunch) and 8 mg/kg (dinner); there will then be an interval of 14 days without treatment. Within the second 28-day period, PTC124 treatment will be taken 3 times per day with meals for 14 days at doses of 10 mg/kg (breakfast), 10 mg/kg (lunch) and 20 mg/kg (dinner); there will then be an interval of 14 days without treatment. There will be a 2-night stay at the clinical research center at the beginning and at the end of each 14 days of PTC124 treatment, which means that there will be four 2-night stays at the clinical research center during the study. During the study, PTC124 efficacy, safety, and pharmacokinetics will be evaluated periodically with measurement of transepithelial potential difference (TEPD), nasal mucosal brushing to assess for cellular CFTR mRNA and protein, medical history, physical examinations, blood tests, urinalysis, ECGs, chest x-ray, and pulmonary function tests.