A Study of PTC923 in Participants With Phenylketonuria

Completed · Phase 3 · Has a placebo group

Conditions studied: Phenylketonuria

In brief

The main purpose of this trial is to evaluate the efficacy of PTC923 in reducing blood phenylalanine (Phe) levels in participants with phenylketonuria as measured by mean change in blood Phe levels from baseline to Weeks 5 and 6 (that is, the average of each respective treatment dose 2-week period of double-blind treatment).

Key facts

Study ID

NCT05099640

Run by

PTC Therapeutics

People needed

157

Starts

2021-09-30

Expected to finish

2023-05-03

Last updated by the study team

2024-01-10

Who can join

Age: any. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• Uncontrolled blood Phe level ≥360 μmol/L on current therapy anytime during screening and uncontrolled blood Phe level ≥360 μmol/L on current therapy when taking the average of the 3 most recent Phe levels from the participant's medical history (inclusive of the screening value).
• Clinical diagnosis of phenylketonuria with hyperphenylalaninemia (HPA) documented by past medical history of at least 2 blood Phe measurements ≥600 μmol/L.
• 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 study drug.
• Males who are sexually active with women of childbearing potential who have not had a vasectomy must agree to use a barrier method of birth control during the study and for up to 90 days after the last dose of study drug. Males must also refrain from sperm donations during this time period.
• Willing to continue current diet unchanged while participating in the study.

You may not qualify if…

• Gastrointestinal disease (such as irritable bowel syndrome, inflammatory bowel disease, chronic gastritis, and peptic ulcer disease, etc.) that could affect the absorption of study drug.
• History of gastric surgery, including Roux-en-Y gastric bypass surgery or an antrectomy with vagotomy, or gastrectomy.
• History of allergies or adverse reactions to synthetic tetrahydrobiopterin (BH4) or sepiapterin.
• Current participation in any other investigational drug study or use of any investigational agent within 30 days prior to screening.
• Any clinically significant laboratory abnormality as determined by the investigator.
• A female who is pregnant or breastfeeding, or considering pregnancy.
• Serious neuropsychiatric illness (for example, major depression) not currently under medical control, 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.
• Past medical history and/or evidence of renal impairment and/or condition including moderate/severe renal insufficiency (glomerular filtration rate [GFR] <60 milliliters [mL]/minute [min]) and/or under care of a nephrologist.
• Any abnormal physical examination and/or laboratory findings indicative of signs or symptoms of renal disease, including calculated GFR <60 mL/min/1.73 square meter (m\^2).
• Requirement for concomitant treatment with any drug known to inhibit folate synthesis (for example, methotrexate).
• 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-alpha-carbinolamine dehydratase genes.
• Major surgery within the prior 90 days of screening.
• Concomitant treatment with BH4 supplementation (for example, sapropterin dihydrochloride, KUVAN) or pegvaliase-pqpz (PALYNZIQ).
• Unwillingness to washout from BH4 supplementation (for example, sapropterin dihydrochloride, KUVAN) or pegvaliase-pqpz (PALYNZIQ)

Where it is running

• Pediatric Surgery Center — Tbilisi, Georgia
• Stanford University Center for Academic Medicine — Stanford, California, United States
• University of Colorado and the Children's Hospital CO — Aurora, Colorado, United States
• UF College of Medicine, Department of Pediatrics Division of Genetics and Metabolism — Gainesville, Florida, United States
• Indiana University School of Medicine — Indianapolis, Indiana, United States
• Boston Children's Hospital — Boston, Massachusetts, United States
• Icahn School of Medicine at Mount Sinai (ISMMS) — New York, New York, United States
• The Children's Hospital of Philadelphia — Philadelphia, Pennsylvania, United States
• UPMC Children's Hospital of Pittsburgh — Pittsburgh, Pennsylvania, United States
• Children's Medical Center Dallas — Dallas, Texas, United States
• University of Texas Health Science Center of Texas — Houston, Texas, United States
• University of Utah, Division of Medical Genetics (pediatric and adult clinic) — Salt Lake City, Utah, United States
• Medical College of Wisconsin — Milwaukee, Wisconsin, United States
• Westmead Hospital — Westmead, New South Wales, Australia
• PARC Clinical Research — Adelaide, South Australia, Australia
• Royal Melbourne Hospital — Melbourne, Victoria, Australia
• Hospital de clinicas de Porto Alegre — Porto Alegre, Rio Grande do Sul, Brazil
• Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo — Ribeirão Preto, São Paulo, Brazil
• Metabolics and Genetics in Calgary (MAGIC) Clinic, Ltd. — Calgary, Alberta, Canada
• The Hospital for Sick Children University of Toronto, Adult Clinic: The Fred A Litwin Family Centre in Genetic Medicine University Health Network & Mt. Sinai Hospital — Toronto, Ontario, Canada
• Copenhagen University Hospital, Rigshospitalet — Copenhagen, Denmark
• Bretonneau Hospital - CHRU de Tours — Tours, Centre-Val de Loire, France
• CHRU de Tours- Hôpital Pédiatrique de Clocheville — Tours, Centre-Val de Loire, France
• University Children's Hospital Hamburg Eppendorf (Kinder-UKE) Klinik für Kinder- und Jugendmedizin (Kinder-UKE) — Hamburg, Germany
• Universitätsklinikum Heidelberg / Zentrum für Kinder- und Jugendmedizin / Sektion für Neuropädiatrie & Stoffwechselmedizin — Heidelberg, Germany

Full record on ClinicalTrials.gov

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