A Phase 1 interventional study of AG-181 in Phenylketonuria, sponsored by Agios Pharmaceuticals, Inc.. Recruiting at 5 sites in 2 countries. Open to participants aged 18 Years to 69 Years. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by Agios Pharmaceuticals, Inc. · Phase 1, Interventional, and Treatment
The primary purpose of this study is to assess the safety and tolerability of AG-181 in subjects with Phenylketonuria (PKU).
191 studies on the registry are indexed under Phenylketonurias; 40 are open to participants now.
This study's planned enrollment of 20 is below the median of 27 across 122 interventional studies indexed under Phenylketonurias.
Browse Phenylketonurias studies →Agios Pharmaceuticals, Inc. is the lead sponsor of 52 studies on the registry; 6 are open to participants now.
Of its 23 completed or terminated interventional studies of FDA-regulated products, 4 (17%) have results posted.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria:
Key Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CYP3A (CYP3A4) inhibitors and inducers
CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.
Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Subjects will receive AG-181 from Day 1 to Day 28.
Drug: AG-181
Subjects will receive AG-181.
Drug: AG-181
AG-181 film-coated tablets
Number of Subjects with Adverse Events (AEs) and Serious Adverse Events (SAEs) by Type, Severity, and Relationship to the Study Drug
Time frame: Up to Day 42
Plasma Concentration of AG-181
Time frame: Up to Day 28
Maximum Concentration (Cmax) of AG-181
Time frame: Up to Day 28
Time to Maximum (Peak) Concentration (Tmax) of AG-181
Time frame: Up to Day 28
Area Under the Concentration-Time Curve (AUC) of AG-181
Time frame: Up to Day 28
Apparent Total Body Clearance (CL/F) of AG-181
Time frame: Up to Day 28
Apparent Volume of Distribution in the Terminal Phase (Vz/F) of AG-181
Time frame: Up to Day 28
Change From Baseline in Phenylalanine (Phe) Concentration
Time frame: Baseline up to Day 28
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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