A Long-Term Safety Study of PTC923 in Participants With Phenylketonuria

Launched by PTC THERAPEUTICS · Dec 8, 2021

Keywords

ClinConnect Summary

This clinical trial is looking at the long-term safety of a medication called PTC923 for people with a condition known as phenylketonuria (PKU). PKU is a genetic disorder that affects how the body processes a substance called phenylalanine, which is found in many protein-rich foods. The study aims to see how well this medication works over time and how it affects participants' dietary habits, particularly their intake of phenylalanine and protein.

To be eligible for the trial, participants need to have a clinical diagnosis of PKU and a history of high phenylalanine levels in their blood. They should be willing to keep their current diet the same during the study, unless instructed otherwise. Women who can become pregnant must have a negative pregnancy test and agree to use effective birth control, while sexually active men must also use a barrier method of contraception. Participants will be carefully monitored throughout the study, and they can expect support and guidance from the research team. If you're considering joining this study, it's important to discuss it with your healthcare provider to understand if it's right for you.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Clinical diagnosis of PKU 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 the 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 (unless specifically instructed to change diet during the study by the investigator).
• Exclusion Criteria:
• • Inability to tolerate oral medication.
• • 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 PTC, 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 \[min\] min as estimated most recently during qualifying participation in a feeder study) and/or under care of a nephrologist.
• • Any other condition that in the opinion of the investigator or PTC, would interfere with the participant's ability to participate in the study or increase the risk of participation for that participant.
• • Requirement for concomitant treatment with any drug known to inhibit folate synthesis (for example, methotrexate).
• • Concomitant treatment with tetrahydrobiopterin (BH4) supplementation (for example, sapropterin dihydrochloride, KUVAN) or pegvaliase-pqpz (PALYNZIQ).
• Additional criteria for non-feeder participants who did not participate in a feeder study:
• • 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 BH4 or sepiapterin.
• • Any clinically significant laboratory abnormality as determined by the investigator.
• • Any abnormal physical examination and/or laboratory findings indicative of signs or symptoms of renal disease, including calculated GFR \<60 milliliters (mL)/minute/1.73 square meter (m\^2).
• • Confirmed diagnosis of a primary BH4 deficiency as evidenced by biallelic pathogenic mutations in 6-pyruvoyltetrahydropterin synthase, recessive GTP cyclohydrolase I, sepiapterin reductase, quinoid dihydropteridine reductase, or pterin-4-alphacarbinolamine dehydratase genes.