Study of Ataluren (PTC124™) in Cystic Fibrosis

PTC Therapeutics238 enrolled

Overview

Cystic fibrosis (CF) is a genetic disorder caused by a mutation in the gene that makes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. A specific type of mutation called a nonsense (premature stop codon) mutation is the cause of CF in approximately 10% of patients with the disease. Ataluren is an orally delivered investigational drug that has the potential to overcome the effects of the nonsense mutation. This study is a Phase 3 trial that will evaluate the clinical benefit of ataluren in adult and pediatric participants with CF due to a nonsense mutation. The main goals of the study are to understand whether ataluren can improve pulmonary function and whether the drug can safely be given for a long period of time. The study will also assess the effects of ataluren on CF pulmonary exacerbation frequency, cough frequency, health-related quality of life, antibiotic use for CF-related infections, CF-related disruptions to daily living, body weight, and CF pathophysiology.

This study is a Phase 3, multicenter, randomized, double-blind, placebo-controlled, efficacy and safety study, designed to document the clinical benefit of ataluren when administered as therapy of participants with CF due to a nonsense mutation (premature stop codon) in the CFTR gene. It is planned that \~208 participants who are ≥6 years of age and have a forced expiratory volume in 1 second (FEV1) ≥40% and ≤90% of predicted will be enrolled. Study participants will be enrolled at sites in North America, Europe, and Israel. They will be randomized in a 1:1 ratio to either ataluren or placebo. Participants will receive study drug 3 times per day (at morning, midday, and evening) for 48 weeks. Participants will be evaluated at clinic visits every 8 weeks. Additional safety laboratory testing, which may be performed at the investigational site or at an accredited local laboratory or clinic, is required every 4 weeks for the first 6 months of study participation. At the completion of blinded treatment, all compliant participants will be eligible to receive open-label ataluren in a separate extension study.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Eligibility

Sex: ALLMin age: 6 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Ability to provide written informed consent (parental/guardian consent and participant assent if \<18 years of age) * Age ≥6 years * Body weight ≥16 kg * Abnormal nasal transepithelial potential difference (TEPD) total chloride conductance (a less electrically negative value than -5 millivolts (mV) for total chloride conductance \[Δchloride-free+isoproterenol\]) * Sweat chloride \>40 milliequivalents/liter (mEq/L) * Documentation of the simultaneous presence of a nonsense mutation in at least 1 allele of the CFTR gene and a CF-causing mutation in the other CFTR allele, as determined by gene sequencing from a laboratory certified by the College of American Pathologists (CAP), under the Clinical Laboratory Improvement Act/Amendment (CLIA), or by an equivalent organization * Verification that a blood sample has been drawn for confirmation of the presence of a nonsense mutation in the CFTR gene * Ability to perform a valid, reproducible spirometry test using the study-specific spirometer with demonstration of an FEV1 ≥40% and ≤90% of predicted for age, gender, and height * Resting oxygen saturation (as measured by pulse oximetry) ≥92% on room air * Documentation by VivoMetrics that the participant has satisfactorily completed a 24-hour LifeShirt® cough frequency assessment * Confirmed screening laboratory values within the central laboratory ranges (hepatic, adrenal, renal, serum electrolytes, and reproduction \[women only\] parameters) * In participants who are sexually active, willingness to abstain from sexual intercourse or employ a barrier or medical method of contraception during the study drug administration and 4-week follow-up period * Willingness and ability to comply with scheduled visits, drug administration plan, study restrictions, and study procedures Exclusion Criteria: * Known hypersensitivity to any of the ingredients or excipients of the study drug * Any change (initiation, change in type of drug, dose modification, schedule modification, interruption, discontinuation, or reinitiation) in a chronic treatment/prophylaxis regimen for CF or for CF-related conditions within 4 weeks prior to start of study treatment * Exposure to another investigational drug within 4 weeks prior to start of study treatment * Treatment with systemic aminoglycoside antibiotics at the time of the Baseline TEPD assessment * Treatment with intravenous antibiotics within 3 weeks prior to start of study treatment * History of solid organ or hematological transplantation * Ongoing immunosuppressive therapy (other than corticosteroids) * Ongoing warfarin, phenytoin, or tolbutamide therapy * Ongoing participation in any other therapeutic clinical trial * Major complications of lung disease (including massive hemoptysis, pneumothorax, or pleural effusion) within 8 weeks prior to start of study treatment * Evidence of pulmonary exacerbation or acute upper or lower respiratory tract infection (including viral illnesses) within 3 weeks prior to randomization * Known portal hypertension * Positive hepatitis B surface antigen, hepatitis C antibody test, or human immunodeficiency virus (HIV) test * Pregnancy or breast-feeding * Current smoker or a smoking history of ≥10 pack-years (number of cigarette packs/day \* number of years smoked) * Prior or ongoing medical condition (for example, concomitant illness, alcoholism, drug abuse, psychiatric condition), medical history, physical findings, electrocardiography findings, or laboratory abnormality that, in the Investigator's opinion, could adversely affect the safety of the participant, makes it unlikely that the course of treatment or follow-up would be completed, or could impair the assessment of study results.

Locations (38)

University of Alabama-Birmingham

Birmingham, Alabama, United States

Miller Children's Hospital Long Beach

Long Beach, California, United States

Lucile Packard Children's Hospital

Palo Alto, California, United States

Stanford

Palo Alto, California, United States

Rady Children's Hospital - San Diego

San Diego, California, United States

Outcomes

Primary Outcomes

Percentage of Predicted Function (Percent-Predicted) of Forced Expiratory Volume in One Second (FEV1) at Baseline

Time frame: Baseline (Week 1)

Percentage Change From Baseline in Percent-Predicted of FEV1 at Week 48

Spirometry was used to assess pulmonary function by measuring the percentage of predicted function, which was determined on the basis of the height value obtained at the same study visit, for FEV1 (the amount of air that can be exhaled in 1 second). Spirometry was assessed by using current guidelines of the American Thoracic Society (ATS) and European Respiratory Society (ERS). The percentage of change in percent-predicted of FEV1 was calculated as follows: (\[percent-predicted FEV1-Baseline percent-predicted FEV1\]/Baseline percent-predicted FEV1)\*100. Baseline was the average of percent-predicted FEV1 at screening and randomization. A negative change from Baseline indicates that percent-predicted of FEV1 decreased.

Time frame: End of Treatment (EOT) (Week 48)

Secondary Outcomes

Rate of Pulmonary Exacerbations as Defined by Modified Fuch's Criteria Over 48 Weeks

A Respiratory Event Form, which collected data on various signs, symptoms, and effects for each event, was completed by the Investigator when informed by the participant of a respiratory event. Pulmonary exacerbations were assessed by using the modified Fuchs' criteria, which defines an exacerbation as a respiratory event requiring treatment with parenteral antibiotics for any 4 of the following 12 symptoms, with or without intravenous antibiotics: change in sputum; new or increased hemoptysis; increased cough; increased dyspnea; fatigue; temperature \>38°C; anorexia; sinus pain; change in sinus discharge; change in physical examination of the chest; decrease in pulmonary function by 10% or more from a previously recorded value; or radiographic changes indicative of pulmonary function. The 48-week exacerbation rate was determined by adding the weekly rates for each arm and dividing the sum by 48.

Time frame: Baseline to EOT (Week 48)

Change From Baseline in Awake Cough Hourly Rate at Week 48

The frequency of awake cough was measured using the LifeShirt, which incorporates motion-sensing transducers, electrodes, a microphone, and a 3-axis accelerometer into a lightweight vest. The rate was determined by dividing the total number of coughs by 24 (the number of hours of the observation period). Baseline was the latest, valid assessment prior to the treatment. A negative change from Baseline indicates that coughing decreased.

Time frame: Baseline, EOT (Week 48)

Change From Baseline in the Respiratory Domain Score of the Revised Cystic Fibrosis Questionnaire (CFQ-R) at Week 48

The CFQ-R consists of 44 items, including generic scales of physical functioning, role functioning, vitality, health perceptions, emotional functioning, and social functioning, and CF-specific scales of respiratory and digestive symptoms, body image, eating disturbances, and treatment burden. Each domain score ranges from 1 to 4. Scores were linearly transformed to a 0 to 100 scale, with higher scores indicating better health. Domain scores were calculated by using the following formula: 100 \* (sum of responses - minimum possible sum)/ (maximum possible sum - minimum possible sum). The minimum possible sum = number of questions \* 1; the maximum possible = the number of questions \* 4. Baseline was the latest, valid assessment prior to the treatment. A negative change from Baseline indicates that health has worsened. Participants may have switched age groups during the study.

Time frame: Baseline, EOT (Week 48)

Percent-Predicted of Forced Vital Capacity (FVC) at Baseline

Time frame: Baseline (Week 1)

Percentage Change From Baseline in Percent-Predicted of FVC at Week 48

Spirometry was used to assess pulmonary function by measuring the percentage of predicted function, which was determined on the basis of the height value obtained at the same study visit, for FVC (the amount of air that can be exhaled after taking a deep breath). Spirometry was assessed by using current guidelines of the ATS and ERS. The percentage of change in percent-predicted of FVC was calculated as follows: ((percent-predicted FVC-Baseline percent-predicted FVC)/Baseline percent-predicted FVC)\*100. Baseline was the average of percent-predicted FVC at screening and randomization. A negative change from Baseline indicates that percent-predicted of FVC decreased.

Time frame: EOT (Week 48)