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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT05270837
Recruitment Status : Active, not recruiting
First Posted : March 8, 2022
Last Update Posted : September 28, 2023
Information provided by (Responsible Party):
BioMarin Pharmaceutical

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.

Condition or disease Intervention/treatment Phase
Phenylketonuria (PKU) Drug: Pegvaliase Other: Diet Only Phase 3

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.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 55 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Phase 3 Multi-Center Study to Evaluate the Safety and Efficacy of Subcutaneous Injections of Pegvaliase in Adolescent Subjects (Ages 12-17) With Phenylketonuria Featuring an Open-Label Randomized Two-Arm (Active vs Diet-Only Control) Design
Actual Study Start Date : June 17, 2022
Estimated Primary Completion Date : December 2025
Estimated Study Completion Date : December 2025

Arm Intervention/treatment
Experimental: Pegvaliase Drug: Pegvaliase
Pegvaliase 2.5mg/10mg/20mg/40mg/60mg self-administered from 1 time up to 7 times a week
Other Names:
  • BMN 165

Drug: 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 145.
Other: Diet Only
Diet Control

Primary Outcome Measures :
  1. Change in blood Phe concentration [ Time Frame: Treatment naïve baseline following 72 weeks on study ]
  2. Incidence of treatment-emergent adverse events as assessed by CTCAE v5.0 [ Time Frame: Treatment naïve baseline following 72 weeks on study ]

Secondary Outcome Measures :
  1. Change in total dietary protein intake [ Time Frame: Treatment naïve baseline following 72 weeks on study ]

Other Outcome Measures:
  1. Characterize area under plasma concentration time curve (AUC) of pegvaliase [ Time Frame: Baseline to 153 weeks ]
  2. Characterize maximum plasma concentration (Cmax) of pegvaliase [ Time Frame: Baseline to 153 weeks ]
  3. Characterize trough plasma concentration (Ctrough) of pegvaliase [ Time Frame: Baseline to 153 weeks ]
  4. Characterize time to reach maximum plasma concentration (Tmax) of pegvaliase [ Time Frame: Baseline to 153 weeks ]

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   12 Years to 17 Years   (Child)
Sexes Eligible for Study:   All
Accepts 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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT05270837

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Sponsors and Collaborators
BioMarin Pharmaceutical
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Study Chair: Study Director BioMarin Pharmaceutical
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Responsible Party: BioMarin Pharmaceutical Identifier: NCT05270837    
Other Study ID Numbers: 165-306
First Posted: March 8, 2022    Key Record Dates
Last Update Posted: September 28, 2023
Last Verified: September 2023

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by BioMarin Pharmaceutical:
Subcutaneous Injections
adolescent PKU
Additional relevant MeSH terms:
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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
Metabolic Diseases