A Study of Sepiapterin in Participants With Phenylketonuria (PKU)

Phenylketonuria Clinical Trial

— EPIPHENY  

Official title:

A Phase 3b Open-Label Study of Long-Term Neurocognitive Outcomes in Children With Phenylketonuria Treated With Sepiapterin

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06302348
• Other study ID #: PTC923-PKU-401
• Status: Recruiting
• Phase: Phase 3
• Start date: March 4, 2024
• Est. completion date: February 28, 2031

Study information

• Verified date: April 2024
• Source: PTC Therapeutics
• Contact: Patient Advocacy
• Phone: 1-866-562-4620
• Email: medinfo[@]ptcbio.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The main purpose of this trial is to evaluate the long-term efficacy of sepiapterin on preserving neurocognitive functioning in children with PKU when treatment is initiated in early childhood.

Description:

The study includes 2 parts: Part 1 and 2. Part 1 is a sepiapterin-responsiveness test, and Part 2 is an open-label treatment period.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 56
• Est. completion date: February 28, 2031
• Est. primary completion date: February 28, 2031
• Accepts healthy volunteers: No
• Gender: All
• Age group: N/A to 12 Years

Eligibility

Key Inclusion Criteria:

• Women of childbearing potential must have a negative pregnancy test at screening and agree to abstinence or the use of at least one highly effective form of contraception for the duration of the study, and for up to 90 days after the last dose of the study drug.

• Established diagnosis of PKU with hyperphenylalaninemia (HPA) evidenced by at least 1 blood Phe measurement >600 µmol/L as documented in the medical history.

• For participants =1 month of age, a minimum of 1 documented blood Phe measurement <480 µmol/L within 1 month prior to Screening.

• For participants =1 month of age, 2 screening blood Phe concentration values must be in the range =120 to =480 µmol/L.

• Willing to continue prescribed diet during Screening and Part 1.

• For participants =30 months to <12 years of age, baseline FSIQ score =80.

Key Exclusion Criteria:

• History of allergies or adverse reactions to synthetic tetrahydrobiopterin (BH4) or sepiapterin.

• Serious neuropsychiatric illness (for example, major depression) not currently under medical control or other concurrent disease or condition that, in the opinion of the investigator or sponsor, would interfere with the participant's ability to participate in the study or increase the risk of participation for that participant.

• Treatment with BH4 supplementation (sapropterin dihydrochloride, KUVAN) within 3 months prior to Screening.

• Current participation in another investigational drug study or use of any investigational agent within 30 days prior to Screening.

• Confirmed diagnosis of a primary BH4 deficiency as evidenced by biallelic pathogenic mutations in 6-pyruvoyltetrahydropterin synthase, recessive Guanosine-5'-triphosphate (GTP) cyclohydrolase I, sepiapterin reductase, quinoid dihydropteridine reductase, or pterin 4-alphacarbinolamine dehydratase genes.

• Any clinically significant laboratory abnormality as determined by the investigator.

• Any past medical history of an abnormal physical examination and/or laboratory findings indicative of signs or symptoms of renal disease, including calculated (Bedside Schwartz Equation) glomerular filtration rate (GFR) <60 milliliters (mL)/minute (min)/1.73 square meter (m^2).

• Major surgery within the prior 90 days of Screening.

Note: Other protocol-defined inclusion and exclusion criteria may apply.

Related Conditions & MeSH terms

• Phenylketonuria
• Phenylketonurias

Intervention

Drug:
• Sepiapterin
Sepiapterin powder for oral use will be suspended in water or apple juice prior to administration.

Locations

Country	Name	City	State
United States	Indiana University	Indianapolis	Indiana

Sponsors (1)

Lead Sponsor	Collaborator
PTC Therapeutics

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mean Change From Baseline in Full-scale Intelligence Quotient (FSIQ) Weschler Preschool and Primary Scale of Intelligence - Fourth Edition (WPPSI-IV) Score	Analysis for participants aged =30 months to <6 years.	Baseline, Year 2
Primary	Mean Change From Baseline in FSIQ Weschler Intelligence Scale for Children - Fifth Edition (WISC-V) Score	Analysis for participants aged =6 years to 16 years.	Baseline, Year 2
Secondary	Change From Baseline in Phenylketonuria-Quality of Life (PKU-QOL) Questionnaire Score		Baseline up to 4 years
Secondary	Change From Baseline in the European Quality of Life - 5 Dimensions (EQ-5D) Score		Baseline up to 4 years
Secondary	Mean Change From Baseline in FSIQ (WPPSI-IV) Score	Analysis for participants aged =30 months to <6 years.	Baseline, Year 4
Secondary	Mean Change From Baseline in FSIQ (WISC-V) Score	Analysis for participants aged =6 years to 16 years.	Baseline, Year 4
Secondary	Change From Baseline in Mean Blood Phe Levels		Baseline up to 6 years