Clinical trial Recruiting at 1 site Phase 1 Interventional Ages 18 to 55

PL54 injection safety in adults with PKU

Official title: A Phase I Multicenter Open-label Dose-escalation Study of Safety, Tolerability, PK/PD and Immunogenicity of Single/Multiple Subcutaneous PL54 Injection in Adult PKU Patients

Run by Chongqing Peg-Bio Biopharm Co., Ltd. · NCT07672756 · Data updated 2026-11-12

This study tests whether PL54 is safe and tolerable when given once or in multiple weekly shots to adults with phenylketonuria.

Quick facts

PhasePhase 1
Study typeInterventional
Ages18 Years to 55 Years
SexAll
Enrollment48 (estimated)
SponsorChongqing Peg-Bio Biopharm Co., Ltd.
Industry-sponsored
Locations1 site (Hefei, Anhui)
StatusRecruiting
StartedJuly 20, 2025
Main results expectedJune 1, 2027
Study endsAugust 1, 2027
Registry record updatedJuly 1, 2026
Trial IDNCT07672756 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Adults aged 18–55 with diagnosed PKU and elevated phenylalanine levels who can maintain dietary stability and consent to the trial.

Probably not a fit

Patients with hypersensitivity to PL54 or with conditions that exclude trial participation may not benefit.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This multicenter, open-label Phase 1 trial evaluates the safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of PL54 in adults with PKU. It has two parts: Phase Ia tests single subcutaneous doses across five weight-based groups, followed by a 2-week screening and 4-week safety follow-up; Phase Ib tests four weekly injections with ongoing safety monitoring and ADA/PK analyses. Dose escalation to new groups depends on safety data and a Safety Monitoring Committee decision. About 30 subjects are planned for Phase Ia and around 18 for Phase Ib, enrolled at The First Affiliated Hospital of Anhui Medical University in China. The study will assess how body weight influences dose and how repeated dosing affects safety and immune responses.

Why it matters

Potential benefit: If successful, PL54 could offer a new therapeutic option for lowering or managing phenylalanine levels in PKU.

How similar studies have gone: Open-label Phase 1 studies of similar subcutaneous biologics in PKU have shown acceptable safety in early doses, but this exact approach is exploratory for PL54.

Who can join: the full rules

Show full inclusion / exclusion criteria
Key Inclusion Criteria:

* 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.

Key Exclusion Criteria:

* 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.
* Prior use of any gene therapy for phenylketonuria (including participation in clinical studies).
* Any other condition deemed by the investigator to preclude participation in the trial.

Where it's running

  • The First Affiliated Hospital of Anhui Medical University
    Hefei, Anhui, China
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.