A Clinical Study on the Safety and Tolerability of PL54 Injection in Adult Patients With Phenylketonuria (PKU)

NCT07672756 | Recruiting Phase 1 DMC

• 1 other identifier: PL54-A101
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

The primary objective of this clinical trial is to evaluate the safety and tolerability of single and multiple administrations of PL54 in patients aged 18-55 years. The key questions it aims to answer include: How safe and tolerable is PL54 in PKU patients following single and multiple administrations? Researchers will compare the safety and tolerability profiles between single and multiple dosing regimens to assess PL54. Participants will be required to: Phase Ia (Single Administration): Receive a single subcutaneous injection of PL54 based on body weight. Undergo a 28-day observation period post-injection. Visit the clinic for assessments on: D1 (administration day), D2, D7, D8, D10, D15, D22, and D29. Phase Ib (Multiple Administrations): Receive subcutaneous injections of PL54 every 7 days (4 doses total) based on body weight. Undergo a 35-day observation period after the last injection. Visit the clinic for assessments on: D1 (first administration), D3, D8, D15, D21, D22, D29, D36, D43, and D57 Data to be recorded include: Incidence, severity, seriousness, relationship to PL54 treatment, duration, and outcome of adverse events (AEs). Change from baseline in blood phenylalanine (Phe) concentration.

Conditions

Phenylketonuria (PKU)

Keywords

Phenylketonuria; PKU

Outcome Measures

Primary Outcomes (1)

• Adverse Events (AEs)

  including the incidence of overall and categorized AEs

  Day 1-29 of Phase Ia; Day 1-57 of Phase Ib

Secondary Outcomes (4)

• The change in blood phenylalanine concentration from baseline

  Day 1-29 of Phase Ia; Day 1-57 of Phase Ib

• The proportion of subjects whose blood phenylalanine concentration decreased to the target range (60-600 μmol/L)

  Day 1-29 of Phase Ia; Day 1-57 of Phase Ib

• PK parameters of PL54 after single dose and multiple doses

  Day 1-29 of Phase Ia; Day 1-57 of Phase Ib

• Immunogenicity of PL54

  Day 1-29 of Phase Ia; Day 1-57 of Phase Ib

Study Arms (1)

PL54

EXPERIMENTAL

subcutaneous injection administration. Single -dose escalation will start from the initial dose of 0.01 mg/kg and proceed sequentially to higher doses.

Biological: PL54

Interventions

PL54 BIOLOGICAL

Phase Ia: Single, subcutaneous injection administration. Dose escalation will start from the initial dose of 0.01 mg/kg and proceed sequentially to higher doses. Phase Ib: Administration via subcutaneous injection. Dosing frequency: once weekly. Dose escalation will start from the initial dose of 0.04 mg/kg and proceed sequentially to higher doses.

Also known as: PEGylated Recombinant Phenylalanine Ammonia-Lyase

PL54

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Adult patients aged 18 to 55 years, inclusive, regardless of sex.
• Subjects with a prior diagnosis of phenylketonuria (PKU) meeting the following criteria:
• Blood Phe concentration ≥600 µmol/L at screening;
• Average blood Phe concentration ≥600 μmol/L within the 12 months prior to screening (with at least two test results available);
• Genetic test report confirming the presence of phenylalanine hydroxylase (PAH) gene defects.
• Ability to maintain dietary stability from 3 days prior to screening through the end of the trial.
• Subjects (including partners) capable of practicing effective contraception during the trial period, with no plans for conception within 3 months after trial completion.
• Voluntarily sign the informed consent form and, in the investigator's judgment, able to comply with all study requirements.

You may not qualify if:

• Known hypersensitivity to PL54 injection or any of its excipients.
• Medical conditions or history assessed by the investigator that may increase the risk of severe allergic reactions (e.g., acute exacerbation of allergic asthma, atopic constitution, history of anaphylaxis, etc.).
• Use of any medication for PKU (including large neutral amino acids) within 14 days prior to study drug administration or within 5 half-lives of the drug (whichever is longer).
• Use or planned use of any injectable medication containing polyethylene glycol (PEG) (except the investigational drug) within 3 months prior to screening or during the study period, including medroxyprogesterone acetate injection.
• Prior use of Pegvaliase (PALYNZIQ®).
• History of any of the following manifestations associated with prior PEG-containing product use: systemic symptoms (e.g., respiratory or gastrointestinal symptoms, hypotension, angioedema, allergic reactions). The investigator will determine eligibility based on the severity of previous symptoms.
• Clinically significant abnormal vital signs, physical examination, laboratory tests, or other relevant findings at screening, deemed by the investigator to render the subject unsuitable for enrollment.
• Significant medical history of immunological, cardiovascular, respiratory, gastrointestinal, endocrine, renal, hematological, neurological, psychiatric, or malignant diseases (except basal cell carcinoma of the skin or carcinoma in situ of the cervix that has been excised with no evidence of recurrence) assessed by the investigator prior to screening.
• Stable use of immunosuppressants (e.g., cyclosporine, azathioprine) within 4 weeks prior to screening, with inability to discontinue use during the study period.
• Vaccination within 4 weeks prior to screening or planned vaccination during the study period.
• Positive serology for Treponema pallidum-specific antibodies, human immunodeficiency virus (HIV) antibodies, hepatitis C virus (HCV) antibodies, or hepatitis B virus (HBV) surface antigen.
• Serum creatinine ratio \> 1.5 × upper limit of normal (ULN).
• Alanine aminotransferase (ALT) \> 2 × ULN.
• Pregnant or breastfeeding women.
• Participation in any investigational drug trial and receipt of an investigational product within 3 months prior to screening.

Sponsors & Collaborators

• Chongqing Peg-Bio Biopharm Co., Ltd.: lead

Study Sites (1)

The First Affiliated Hospital of Anhui Medical University

Hefei, Anhui, 230022, China

RECRUITING

MeSH Terms

Conditions

Phenylketonurias

Condition Hierarchy (Ancestors)

Brain Diseases, Metabolic, Inborn; Brain Diseases, Metabolic; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Amino Acid Metabolism, Inborn Errors; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases

Central Study Contacts

Jing Sun

CONTACT

86-13983367811; sunj@pegbiocq.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 17, 2026
• First Posted: June 29, 2026
• Study Start: July 20, 2025
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: July 1, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)