Efficacy and Safety of Orally Administered Engineered Probiotics (CBT102-A) for the Treatment of Children With Phenylketonuria

Inclusion Criteria: * Blood phe ≥ 600μmol/L at newborn screening; * Blood phe ≥ 600μmol/L at least 3 times in the last 1 year before screening, and the blood Phe ≥ 600μmol/L in the last 1 time; * Screening laboratory evaluations (e.g., chemistry panel, complete blood count, urinalysis, creatinine clearance, CRP) within normal limits or judged to be not clinically significant by the investigator; * Stable diet for at least 60 days prior to screening; * Able to produce at least 2 bowel movements per week on average without using any form of laxatives; * Adolescents and children's guardians can voluntarily complete the whole process of informed consent, including stool, urine and blood collection, adherence to diet control, hospital monitoring, follow-up and oral trial drug compliance, and sign informed consent. Exclusion Criteria: * The standard percentile values of height and weight of Chinese children aged 0 to 18 years were evaluated with weight less than P3 or weight greater than P97； * History of active or chronic passage of 3 or more loose stools per day； * Have any medical conditions or medications that may affect the absorption of medications or nutrients； * History of or current immunodeficiency disorder including autoimmune disorders； * Subjects with obvious influenza-like symptoms caused by COVID-19 or other viral infections during screening； * Hepatitis B surface antigen and/or hepatitis C antibodies and/or treponema pallidum antibodies positive； * Subjects who are dependent on drugs and alcohol； * Received gene therapy related to PKU； * Intolerant or allergic to Escherichia coli Nissle 1917 (EcN)； * Active gastrointestinal bleeding or a proven history of gastrointestinal bleeding within 60 days prior to screening； * Antibiotics within 28 days before the planned first dose of investigational product (IP), or anticipated during the study period； * Take probiotic supplements within 28 days before the planned first dose of IP, or anticipated during the study period； * A history of fever, confirmed bacteremia, or other active infection within 30 days prior to the planned first dose of IP； * Drugs that use of the digestive system has been used within 30 days prior to the planned first dose of IP; * Drugs that may affect gastrointestinal function has been used within 30 days prior to the planned first dose of IP; * Major survery performed within 90 days before the anticipated first dose of IP or planned surgery or hospitalization during the study period； * Take sapropterin (KUVAN®) within 1 week before the planned first dose of IP； * Use pegylated recombinant phenylalanine ammonia lyase (PALYNZIQ™) within 30 days before the planned first dose of IP； * History of severe immune adverse reactions to PALYZIQ； * Participated in an interventional clinical trial and used the investigational drug within 60 days or 5 half-lives before the planned first dose of IP； * Subjects who may not be able to complete the study for other reasons.