To Evaluate the Safety and Efficacy of GS1168 Injection in Adult Phenylketonuria

December 19, 2025 updated by: Gritgen Therapeutics Co., Ltd.

A Clinical Exploration Study of Adeno-Associated Virus Vector Expressing Human Phenylalanine Hydroxylase Gene in Adult Classical Phenylketonuria

This study is a single-arm, open-label, dose-escalation, exploratory study to evaluate the safety, tolerability, and efficacy of a single administration of GS1168 Injection in Chinese adult phenylketonuria (PKU) with PAH mutation.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
9

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • China
    • Anhui
      • Hefei, Anhui, China, 230022
        • The First Affiliated Hospital of Anhui Medical University
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Understand the purpose and risks of the study and voluntarily sign Informed Consent Forms (ICF).
  2. Male or female, aged 18-55 years.
  3. Diagnosis of PKU due to PAH mutation, and be inadequately controlled with current therapy (e.g., dietary management) in the judgement of the investigator.
  4. Intolerant of unresponsive to available treatment such as Kuvan or Palynziq, and have come off the medication for at least 28 days prior to signing the ICF.
  5. Ability and willingness to maintain dietary protein intake consistent with baseline
  6. Male and female subjects of childbearing potential must agree to use effective contraception methods from signing ICF until at least 52 weeks after GS1168 infusion. Female subjects must not be breastfeeding.
  7. Agree to avoid alcohol consumption from 30 days prior to GS1168 infusion until at least 52 weeks after infusion.
  8. Ability to communicate well with the Investigator and to understand and comply with the requirements of the study.

Exclusion Criteria:

  1. Diagnosis of PKU due to other gene mutations.
  2. Body weight ≥100 kg or Body Mass Index (BMI) ≥30 kg/m² at screening.
  3. Presence of anti-AAV8 neutralizing antibody.

  4. Abnormal liver function tests at screening:

    • ALT or AST >1.25 × Upper Limit of Normal (ULN)
    • GGT >1.25 × ULN
    • Total Bilirubin >1.5 × ULN

  5. Abnormal laboratory findings at screening:

    • Hemoglobin <9 g/dL
    • Neutrophil count <1.0 × 10⁹/L
    • Platelet count <100 × 10⁹/L
    • Serum Creatinine ≥1.5 mg/dL (133 μmol/L)
    • Glycated Hemoglobin (HbA1c) >6% or Fasting Blood Glucose >6.1 mmol/L
  6. Active or occult hepatitis B virus (HBV) infection, active hepatitis C virus (HCV) infection, positive Human Immunodeficiency Virus (HIV) antibodies and positive syphilis test.
  7. Any severe conditions of respiratory, cardiovascular, gastrointestinal, renal, neurological, endocrine, immunological, hematological, psychiatric, etc.
  8. History of malignancy.
  9. Any other condition that, in the opinion of the Investigator, may affect subject compliance or render the subject unsuitable for participation in this trial.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Treatment group Arm of GS1168
Dose level 1, level 2 and level 3 will be administered
Drug: GS1168 injection

The dose levels are as follows:

  1. A single intravenous administration of GS1168 injection at dose level 1;
  2. A single intravenous administration of GS1168 injection at dose level 2;
  3. A single intravenous administration of GS1168 injection at dose level 3.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of adverse event (AE), including serious adverse event (SAE) and adverse event of special interest (AESI)
Time Frame: Week 52
Incidence of adverse event (AE), including serious adverse event (SAE) and adverse event of special interest (AESI) as assessed by CTCAE V5.0, from baseline to week 52
Week 52

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Plasma Phe levels
Time Frame: Week 52
Change from baseline in plasma level of Phe following GS1168 injection administration
Week 52
Total protein intake
Time Frame: Week 52
Change from baseline in total protein intake following GS1168 injection administration
Week 52
Phenylketonuria Quality of Life (PKU-QOL) scores
Time Frame: Week 52
Change in Phenylketonuria Quality of Life Questionnaire (PKU-QOL, Score range: 0-100, higher scores indicate worse outcomes.)
Week 52

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Gritgen Therapeutics Co., Ltd.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 31, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 30, 2031

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
December 1, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 19, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 6, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 6, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 19, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • GS1168-201

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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