Pegvaliase: Pegvaliase 2.5mg/10mg/20mg/40mg/60mg self-administered from 1 time up to 7 times a week
Diet Only: Diet Control
Study summary
This is a Phase 3 open-label randomized controlled study enrolling approximately 54 adolescents with PKU. The study is designed to assess the safety and efficacy of pegvaliase injections.
Eligibility
Sex
ALL
Min age
12 Years
Max age
17 Years
Healthy volunteers
No
Inclusion Criteria
* Is 12 to 17 years old (US), inclusive, or 12 to 15 years (EU), inclusive, at the start of the Screening/Run-in Period (Day -28).
* Diagnosis of PKU and failure to maintain recommended blood Phe levels on existing management (sapropterin dihydrochloride and Phe-restricted diet) demonstrated by 2 blood Phe concentration measurements \> 600 μmol/L during the Screening/Run-in Period (7 to 10 days in between blood Phe assessments) and average blood Phe concentration \> 600 μmol/L over the past 12 months (per available data).
* Willing and able to maintain and adjust dietary and medical protein food intake according to the study protocol under the supervision of a study dietician or adequately trained designee per investigator discretion during study participation.
* If on medication for ADHD, depression, or other psychiatric disorder, stable dose of medication for ≥ 8 weeks prior to enrollment and willing to maintain stable dose unless a change is medically indicated.
* An adult (≥ 18 years of age) has been identified who is willing and competent to observe the participant during study drug administration and for a minimum of 1 hour following administration.
* Participants must be capable of giving signed informed consent
* If sexually active, male or female participants must not plan to become pregnant (self or partner) and must use 2 acceptable methods of contraception while participating in the study beginning at Screening and for 4 weeks after discontinuing study drug.
Exclusion Criteria
* Previous treatment with pegvaliase.
* Use of any medication that is intended to treat PKU, including the use of large neutral amino acids, within 14 days prior to the administration of study drug on Day 1.
* Use or planned use of any injectable drugs containing polyethylene glycol (PEG; other than pegvaliase), including medroxyprogesterone injection, within 3 months prior to the start of Screening/Run-in and during study participation with the exception of COVID-19 vaccinations.
* A history of organ transplantation or on chronic immunosuppressive therapy.
* Use of any investigational product or investigational medical device within 30 days prior to Screening/Run-in or requirement for any investigational agent prior to completion of all scheduled study assessments.
* A positive test for HIV antibody, hepatitis B surface antigen, or hepatitis C antibody.
* Alanine aminotransferase (ALT) concentration \> 2 × the upper limit of normal (ULN).
* Creatinine \> 1.5 × ULN.
* Inability to identify and/or communicate to others that the participant is experiencing symptoms of potential anaphylaxis due to cognitive impairment or other reasons.
Primary outcome measure(s)
Change From Baseline in Blood Phe Concentration Following 72 Weeks (Average of the Week 69 and Week 73) on Study. — Baseline to Week 72 (average of the Week 69 and Week 73) The blood Phe measurement following 72 weeks on study is defined as the average of the Week 69 and Week 73 blood Phe measurements. Change from baseline in blood Phe will be compared between participants in the active (pegvaliase) and the control (diet-only) treatment arms.
Baseline blood Phe concentration at Part 1 was defined as the average of 3 pre-treatment measurements collected between Screening/Run-in (2) and Day 1 pre-dose (1).
Incidence of Treatment-emergent Adverse Events (Part 1) — Up to Week 73 Treatment-emergent adverse events (TEAE) is defined as any AE that newly appeared or worsened in severity after first dose of pegvaliase (pegvaliase arm) or on or after study day 1 (diet-only arm) until 30 days after last dose of the study.
Serious adverse event (SAE).
Percentage of Participants With Positive Anti-pegvaliase Total Antibody (TAb) — Baseline (Day 1), Week 73 The anti-pegvaliase total antibody (TAb) method captures drug-binding antibodies comprised of different isotypes and specificities.
Antibody Positivity = number of subjects testing positive at any study visit / total number of subjects at study visit.
The baseline was defined as the last non-missing measurement collected prior to the first pegvaliase dose (pegvaliase arm) or prior to or on Visit 1 date (diet-only arm)
Percentage of Participants With Positive PAL IgG Antibody — Baseline (Day 1), Week 73 The presence of immunoglobulin G (IgG) Antibodies against phenylalanine ammonia lyase (PAL) is measured overtime.
The baseline was defined as the last non-missing measurement collected prior to the first pegvaliase dose (pegvaliase arm) or prior to or on Visit 1 date (diet-only arm)
Percentage of Participants With Positive PAL IgM Antibody — Baseline (Day 1), Week 73 The presence of immunoglobulin M (IgM) Antibodies against PAL (phenylalanine ammonia lyase) is measured overtime.
PAL IgM was positive if the titer value was greater than or equal to the median of all baseline PAL IgM titers.
The baseline was defined as the last non-missing measurement collected prior to the first pegvaliase dose (pegvaliase arm) or prior to or on Visit 1 date (diet-only arm)
Percentage of Participants With Positive PEG IgG Antibody — Baseline (Day 1), Week 73 The presence of IgG Antibodies against polyethylene glycol (PEG) is measured overtime
The baseline was defined as the last non-missing measurement collected prior to the first pegvaliase dose (pegvaliase arm) or prior to or on Visit 1 date (diet-only arm)
Percentage of Participants With Positive PEG IgM Antibody — Baseline (Day 1), Week 73 The presence of IgM Antibodies against PEG (polyethylene glycol) is measured overtime
The baseline was defined as the last non-missing measurement collected prior to the first pegvaliase dose (pegvaliase arm) or prior to or on Visit 1 date (diet-only arm)
Percentage of Participants With Positive Neutralizing Antibodies (NAb) — Baseline (Day 1), Week 73 Neutralizing antibodies (NAbs) capable of inhibiting the enzymatic activity of pegvaliase were measured.
The baseline was defined as the last non-missing measurement collected prior to the first pegvaliase dose (pegvaliase arm) or prior to or on Visit 1 date (diet-only arm)
Trial sites (16)
Facility
City
Region
Status
Phoenix Children's Hospital
Phoenix
Arizona
Arkansas Children's Hospital
Little Rock
Arkansas
Children's Hospital of Colorado
Aurora
Colorado
University of South Florida
Tampa
Florida
Ann and Robert H. Lurie Children's Hospital of Chicago
Chicago
Illinois
IU Health University Hospital
Indianapolis
Indiana
University of Kentucky College of Medicine
Lexington
Kentucky
Boston Children's Hospital
Boston
Massachusetts
University of Pittsburgh Medical Center
Pittsburgh
Pennsylvania
McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth)
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
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