A Study of MZE782 in Adults With PKU

• MZE782 (Drug): Tablet, Low Dose
• Placebo (Other): Tablet
• MZE782 (Drug): Tablet, High Dose

Primary outcomes

• Safety and tolerability based on incidence of adverse events (AEs) [Week 0 to Week 17]
• For Cohorts 1A and 1B: Absolute change in plasma Phe levels from Baseline to the mean of plasma Phe levels [Baseline and Weeks 2, 3, and 4]

Secondary outcomes

• For Cohorts 1A and 1B, analyzed separately: Geometric mean plasma concentrations of MZE782 [Weeks 1, 2, 3, 4, 8, and 13]
• For Cohorts 1A and 1B, analyzed separately: Absolute and Percent change in plasma Phe levels from Baseline to the mean of plasma Phe levels [Baseline up to Week 13]
• For Cohorts 1A and 1B, analyzed separately: Proportion of participants with mean plasma Phe levels ≤600 μMol/L, ≤360 μMol/L, and ≤120 μMol/L [Baseline and Weeks 2, 3, 4, 8, 10, and 13]

Sex: All, ages: 18 Years to 75 Years

Key Inclusion Criteria:

* Males and females 18 to 75 years old
* Confirmed diagnosis of PKU
* Willing and able to keep diet and protein intake consistent during the study
* For some study groups, is willing and able to stop certain PKU medications before starting study treatment
* For some study groups, may need to meet additional blood phenylalanine level or background-treatment requirements
* Meets minimum blood phenylalanine level requirements for study group

Key Exclusion Criteria:

* Is pregnant, breastfeeding, or planning to become pregnant or conceive a child during the study
* Medical conditions or abnormal test results that could make participation unsafe or make it difficult to complete study procedures or interpret study results
* Has recently received another investigational drug
* Is unable to swallow tablets or tolerate oral medication

Other inclusion/exclusion criteria defined in protocol apply.

• Medical Director, Study director, Maze Therapeutics