Study to Evaluate the Safety and Efficacy of Pegvaliase in Adolescents (Ages 12-17) With Phenylketonuria

NCT ID: NCT05270837

Last Updated: 2025-09-12

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: PHASE3
• Total Enrollment: 55 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-06-17
• Study Completion Date: 2027-10-31

Brief 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.

Detailed Description

This Phase 3 multicenter study is designed to evaluate the safety and efficacy of pegvaliase administered daily to adolescents (ages 12 to 17 years old (US), inclusive, and 12 to 15 years old (EU), inclusive 12-17) with phenylketonuria (PKU). Participants will be randomized in a 2:1 ratio to the active (pegvaliase) and control (diet-only) treatment arms, respectively, with 36 participants receiving pegvaliase and 18 participants managing their PKU with diet alone.

Conditions

Phenylketonuria (PKU)

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Pegvaliase

Group Type: EXPERIMENTAL

Pegvaliase

Intervention Type: DRUG

Pegvaliase 2.5mg/10mg/20mg/40mg/60mg self-administered from 1 time up to 7 times a week

Diet Only

Participants will be managing their PKU with diet alone. Participants in the diet-only control arm will be required to maintain and adjust dietary and medical protein food intake through Week 72, initiating pegvaliase treatment beginning Week 73 and, from Weeks 73 through 215.

Group Type: OTHER

Diet Only

Intervention Type: OTHER

Diet Control

Interventions

Pegvaliase

Pegvaliase 2.5mg/10mg/20mg/40mg/60mg self-administered from 1 time up to 7 times a week

Intervention Type: DRUG

Diet Only

Diet Control

Intervention Type: OTHER

Other Intervention Names

PEG PAL; BMN 165

Eligibility Criteria

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.

• Minimum Eligible Age: 12 Years
• Maximum Eligible Age: 17 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

BioMarin Pharmaceutical

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Study Director

Role: STUDY_CHAIR

BioMarin Pharmaceutical

Locations

Phoenix Children's Hospital

Phoenix, Arizona, United States

Arkansas Children's Hospital

Little Rock, Arkansas, United States

Children's Hospital of Colorado

Aurora, Colorado, United States

University of South Florida

Tampa, Florida, United States

Ann and Robert H. Lurie Children's Hospital of Chicago

Chicago, Illinois, United States

IU Health University Hospital

Indianapolis, Indiana, United States

University of Kentucky College of Medicine

Lexington, Kentucky, United States

Boston Children's Hospital

Boston, Massachusetts, United States

University of Pittsburgh Medical Center

Pittsburgh, Pennsylvania, United States

McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth)

Houston, Texas, United States

University of Utah Medical Center

Salt Lake City, Utah, United States

University of Virginia School of Medicine

Charlottesville, Virginia, United States

Children's Hospital of Wisconsin

Milwaukee, Wisconsin, United States

Charité - Universitätsmedizin Berlin

Berlin, , Germany

Universitätsklinikum Hamburg-Eppendorf

Hamburg, , Germany

Universitat Mainz

Mainz, , Germany

Countries

United States; Germany

Other Identifiers

165-306

Identifier Type: -

Identifier Source: org_study_id