Overview of Phase 2a Clinical Trial

PTC Therapeutics has initiated a Phase 2a clinical trial of ataluren (formerly referred to as PTC124®) in patients with nonsense mutation hemophilia type A and B (nmHA and nmHB). The trial is a multi-center, open label, dose escalation study. The main goals of the trial are to determine whether treatment with ataluren can result in an increase in Factor VIII or IX levels and whether the drug can safely be given to people with severe hemophilia due to a nonsense mutation.

The trial will last approximately 2 months for each participant. All participants will receive the investigational drug ataluren, which is supplied as a vanilla-flavored powder packaged in an aluminum foil packet. The drug is mixed in water or milk and is taken by mouth. Participants will need to take the ataluren 3 times per day (in the morning, midday, and evening).

In order to determine whether ataluren improves factor levels and the safety of different dose level of ataluren, 2 different doses will be tested in the Phase 2a study. As shown below, the drug will be given in 2 cycles. A lower dose level of ataluren will be given for 14 days. After a break of about 14 days, a higher dose level of ataluren will be given for 14 days and patients will be followed up again about 14 days later.

Cycle 1
o Lower-dose ataluren – 5 milligrams (mg) per kilogram (kg) of body weight in the morning, 5 mg/kg at midday, and 10 mg/kg in the evening – for 14 days
o Approximately 14 days of no ataluren

Cycle 2
o Higher-dose ataluren – 20 mg/kg in the morning, 20 mg/kg at midday, and 40 mg/kg in the evening – for 14 days
o Approximately 14 days of no ataluren with a follow-up visit at the end of that time

Requirements for Participating in this Study
To be eligible for this trial, patients must have a DNA blood test, or genetic test, to determine if their hemophilia is caused by a nonsense mutation. Participants must also meet the following criteria:
• be male
• be at least 18 years of age
• have severe hemophilia type A or B (Factor VIII or Factor IX level less than 1%)
• not be regularly infusing Factor VIII or Factor IX concentrates to prevent bleeding
• not have a history of inhibitors
• not have a history of any bleeding or coagulation abnormalities other than hemophilia

Other eligibility requirements will be explained at the trial site.

• Trial sites
• Frequently Asked Questions
• ClinicalTrials.gov Overview
• Ataluren overview
• Genetic Testing

Additional details about this ataluren clinical trial can be found at www.clinicaltrials.gov or by contacting PTC Therapeutics Patient and Professional Advocacy at (866) 282-5873 or PatientInfo@ptcbio.com.