ClinicalTrials.gov record NCT07672756

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

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 6, 2026

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

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 1An early-stage study, usually small, mainly to check safety, side effects and how much of a treatment can be given. Whether it works is not the main question yet.
Age18 years old to 55 years old
SexAll
LocationChina
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

A Phase I, open‑label study testing single and weekly repeated subcutaneous injections of PL54 in adults with phenylketonuria (PKU). The study's main goal is to assess safety and tolerability and to collect PK/PD and immune-response data. It includes a single‑dose part (several escalating dose groups) and a multiple‑dose part (weekly doses). Key gates: adults 18–55; prior pegvaliase use and recent PKU medications or recent PEG‑containing injectable products are excluded; pregnant or breastfeeding people are excluded.

What it is studying. The study is measuring how safe and tolerable PL54 injections are in adults with PKU, and is collecting pharmacokinetic (PK) and pharmacodynamic (PD) data plus tests for immune responses to the drug. It also records changes in blood phenylalanine levels and tracks adverse events after single and multiple subcutaneous doses.

What the researchers hope to learn. To define the safety and tolerability profile of single and multiple doses of PL54; to describe PL54 pharmacokinetics and pharmacodynamics; to measure effects on blood phenylalanine levels; and to assess immunogenicity (anti‑drug and anti‑PEG antibody responses).

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

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.

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Biological
  • PL54

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

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.

Study description and what participation involves

The study's detailed description, as published on ClinicalTrials.gov.

Show the detailed description from the registry

This is a multicenter, open-label, dose-escalation Phase I clinical study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of single or multiple subcutaneous injections of PL54 injection in adult patients with phenylketonuria (PKU). The trial is divided into Phase Ia and Phase Ib. Phase Ia: A single subcutaneous injection will be administered. The phase includes a 2-week screening period, a single administration on Day 1 (D1), and a 4-week follow-up period, totaling approximately 6 weeks. Approximately 30 subjects will be enrolled across five dose groups: 0.01 mg/kg, 0.04 mg/kg, 0.1 mg/kg, 0.25 mg/kg, and 0.5 mg/kg, with 6 subjects per group (including 1 sentinel). The first subject in each dose group will receive a single subcutaneous injection of PL54, and the remaining subjects in the same dose group will be enrolled only after the first subject has completed at least 14 days of safety assessment. Dose escalation to the next group will proceed only after all subjects in the previous dose group have completed at least 14 days of visit assessments and the Safety Monitoring Committee (SMC) determines that the dose escalation termination criteria have not been met. Phase Ib: Approximately 18 subjects will be enrolled. Subcutaneous injections will be administered once weekly for 4 consecutive weeks (the dosing period for subsequent dose groups may be adjusted based on observed anti-drug antibody [ADA], pharmacokinetic [PK], and pharmacodynamic [PD] results from previous dose groups). Three dose groups are planned: 0.04 mg/kg, 0.1 mg/kg, and 0.25 mg/kg, with 6 subjects per group (the actual dose groups and dosing regimen will be adjusted based on Phase Ia results). Dose escalation to the next group will proceed only after all subjects in the previous dose group have completed at least 28 days of visit assessments and the SMC determines that the dose escalation termination criteria have not been met.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants receive subcutaneous injections of PL54 either as a single dose (Phase Ia) or once weekly for four weeks (Phase Ib). They will attend multiple clinic visits for safety checks and blood tests to measure phenylalanine, drug levels, and antibody responses, and to record any adverse events. Phase Ia involves a 28-day follow-up after the single injection with several scheduled visits; Phase Ib involves a follow-up period after the last of four weekly injections with multiple scheduled visits up to about Day 57. The study includes close safety monitoring and possible dose-escalation steps based on earlier groups' results.

How the study is structured. Multicenter, open‑label, non‑randomized dose‑escalation Phase I trial. Phase Ia enrolls multiple single‑dose groups (sequential escalation with sentinel subject per group). Phase Ib enrolls multiple‑dose groups receiving weekly subcutaneous injections for four weeks (dose escalation based on earlier safety/PK/PD results). Safety is assessed at scheduled clinic visits over several weeks after dosing; no placebo or masking is used.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • This is an early-phase study, mainly about safety and dose. What is already known about this treatment?
  • The listed sites are in China. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on phenylketonuria

Clinical trials38 trials listed for phenylketonuriaEvery trial the registry lists for phenylketonuria, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in phenylketonuria researchLatest monthly update: September 2026. Includes: Diet supply gaps. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Jul 20, 2025
Primary completion
Jun 1, 2027 (estimated)
Study completion
Aug 1, 2027 (estimated)
Target enrollment
48 participants (estimated)
Last updated on registry
Jul 1, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
Chongqing Peg-Bio Biopharm Co., Ltd.

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (1)

  • The First Affiliated Hospital of Anhui Medical UniversityRecruiting

    Hefei, Anhui, 230022 · China

Terms used on this page · explanations by MedicalUpdates.ai

primary objective
The main result the study is designed to measure and report on. Other results, called secondary outcomes, are also collected.
adverse events
Any unwanted medical problem that happens during a study, whether or not it was caused by the treatment. A 'serious' adverse event is one that meets specific criteria, such as causing death, being life-threatening, requiring or prolonging hospital admission, causing significant disability, or another medically important outcome.
baseline
Measurements taken at the start of the study, before any study treatment, so that later results can be compared with them.
at screening
The checks done before enrolment to see whether a person qualifies, such as tests, scans or a review of medical history.
informed consent form
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
study drug
A treatment that is being tested and has not been approved for this use. It may be approved for a different condition. Being studied does not mean it works or is available outside the study.
5 half-lives
The time it takes for the amount of a drug in the body to fall by half. 'Five half-lives' is often used as the point at which a previous drug has essentially left the body.
enrollment
The number of participants a study plans to include, or has included. 'Estimated' means the planned number; 'actual' means the number who joined.
immunosuppressants
A medicine that reduces the activity of the immune system. Studies of autoimmune conditions often require a stable dose, a prior failure, or a washout of such medicines.
upper limit of normal
The highest value of a blood test that a laboratory considers normal. Criteria such as '≤ 3 × ULN' mean the result must be no more than three times that value.
Key Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Key Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.
open-label
No masking is used, so the assigned intervention is not deliberately hidden from participants or study staff.
dose-escalation
Groups of participants receive increasing doses of a treatment, one group after another, to find a dose that can be given safely.
pharmacokinetics
How the body absorbs, distributes, breaks down and removes a drug. It is studied by measuring drug levels or related substances at set times after a dose.
pharmacodynamics
What a drug does to the body, for example how it changes a blood marker or a symptom, and how that relates to the dose.
follow-up
The period after treatment or enrolment during which participants are observed or contacted, for example to record side effects or outcomes.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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