Study of Ataluren (PTC124) in Hemophilia A and B

Number of Participants With a Change From Baseline in Plasma Anti-FVIII/FIX Inhibitor Titers at Day 14

To assess the change from Baseline in plasma anti-FVIII/FIX inhibitor titers, it was determined if any potential antibodies were neutralizing using the Bethesda assay. The Bethesda assay demonstrates antibodies that are neutralizing by quantifying residual FVIII/FIX activity in normal plasma after serial dilutions with participant plasma. For this assay, the neutralizing antibody threshold value was 0.6 Bethesda units (BU).

Time frame: Baseline and Day 14

Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious Adverse Events (SAEs) by Severity and Relationship to Study Drug

The relationship of TEAEs and SAEs to the study drugs was assessed as: probable related, possible related, unlikely related, and unrelated. The severity of TEAEs were graded using the Common Terminology Criteria for Adverse Events, Version 3.0, as: Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe), Grade 4 (life-threatening), or Grade 5 (fatal). A summary of other non-serious adverse events (AEs) and all serious AEs, regardless of causality is located in Reported AE section.

Time frame: Baseline up to Day 28

Number of Participants With a Clinically Meaningful Abnormal Clinical Laboratory (Hematology, Adrenal Assays, Biochemistry, and Urinalysis) Parameters

The Investigator used his/her judgment in determining whether an abnormality was clinically significant, diagnostic evaluation was warranted, and potential interruption of ataluren was appropriate. Life-threatening (Grade 4) or severe (Grade 3) laboratory abnormalities were considered dose-limiting, although recurrent or persistent moderate (Grade 2) events were also considered dose-limiting in certain circumstances. Values considered abnormal included -Hematology: Serum total bilirubin Grade 2 (\>1.5-3.0\*upper limit of normal \[ULN\]) and Serum alanine aminotransferase, Serum aspartate aminotransferase, and Serum gamma glutamyl transferase Grade 2 (\>2.5-3.0\*ULN); -Adrenal: Plasma adrenocorticotropic hormone \>ULN (and cortisol within normal limits); and -Renal: serum creatinine Grade 1 (\>ULN-1.5\*ULN) and Serum blood urea nitrogen ≥1.5-3.0\*ULN. A summary of other non-serious AEs and all serious AEs, regardless of causality is located in Reported AE section.

Time frame: Baseline up to Day 28

Compliance With Ataluren Administration

Ataluren compliance as assessed by quantification of used and unused drug. Data were not collected or analyzed for this measure because participants were terminated early from the study.

Time frame: Baseline up to Day 28

Ataluren Plasma Exposure

The ataluren plasma concentrations before and 2 hours after the first morning dose at end of treatment was measured.

Time frame: Day 10 (pre-dose) and Day 14 (post-dose)

Occurrence of Bleeding Episodes

Frequency, timing, anatomic location, and severity of any bleeding episodes were recorded. A summary of serious and all other non-serious adverse events, regardless of causality, is located in the Reported Adverse Events module.

Time frame: Baseline up to Day 28