Rapid Drug Desensitization Study in Adults Experiencing Hypersensitivity Reactions to Palynziq

NCT06780332 | Completed Phase 4 FDA Drug

• 1 other identifier: 165-402
• Study Type: interventional
• Target: 9
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to determine if rapid drug desensitization (RDD) to Palynziq will improve drug tolerability and treatment persistence in adult patients on commercial Palynziq experiencing hypersensitivity reactions (HSRs) leading to treatment interruption or reduction of dose or dosing frequency. See Section 10.8 for full list of HSR preferred terms. Study details include:

• Study duration: Up to 30 weeks (up to 6 weeks for Screening, then RDD, and 24 weeks of follow-up)
• RDD duration: 1 day
• Palynziq dosing/follow-up duration: 24 weeks
• Palynziq dosing frequency: Individualized

Conditions

Phenylketonuria; PKU

Keywords

Phenylketonuria; PKU; Palynziq; pegvaliase

Outcome Measures

Primary Outcomes (1)

• To determine if RDD to Palynziq improves drug tolerability and treatment persistence in adults with PKU experiencing HSRs leading to treatment interruption or reduction of dose or dosing frequency (reactive HSR).

  Tolerance, defined as the ability to restart Palynziq at the dose at which the reactive HSR occurred (reactive dose) and escalate as appropriate within 24 weeks following the RDD, without requiring treatment interruption or reduction of dose or dosing frequency due to HSRs and reduction in occurrence of HSRs Grade 2 or above within 24 weeks following RDD

  24 weeks

Secondary Outcomes (1)

• To characterize the immune response to Palynziq following RDD

  24 weeks

Study Arms (1)

RDD

EXPERIMENTAL

Participants undergoing RDD to Palynziq

Drug: RDD to Palynziq

Interventions

RDD to Palynziq DRUG

Delivery of gradually increasing doses of Palynziq at fixed time intervals over the course of several hours to a cumulative dose equal to the reactive dose. Reactive dose is defined as the dose at which the reactive HSR occurred which led to treatment interruption or reduction of dose or dose frequency.

RDD

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age:
• Participants must be 18 years of age or older inclusive, at the time of signing the informed consent.
• Type of Participant and Disease Characteristics 2. Participants must have phenylketonuria and must have been receiving commercial Palynziq and enrolled in the REMS.
• \. Participants must have developed HSRs leading to treatment interruption or reduction of dose or dosing frequency (Graade 2 or above) while on Palynziq, and must be able to undergo RDD within 6weeks from the reactive HSR and last Palynziq dose.
• Sex and Contraceptive/Barrier Requirement 4. Males and females are eligible to participate in this clinical study. Contraceptive use is not required during the study. Please refer to the Pregnancy section of USPI for further information.
• Informed Consent 5. Participants must be capable of giving written informed consent as described in Section 10.1, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.

You may not qualify if:

• Medical Conditions:
• Participant may not have any kind of disorders that, in the opinion of the investigator, may compromise the ability of the participant to give written informed consent and/or comply with any aspect of the study, and/or where any aspect of participation would be medically inadvisable for the underlying disorder.
• Participant must not be pregnant on the day of the RDD.
• Participants with uncontrolled asthma, active upper respiratory infection or other active infections, or cardiovascular disease. Asthma control will be assessed using the Asthma Control Test at screening.
• Prior/Concomitant Therapies:
• \. Participants were not using antihistamine premedication(s) at the time of reactive HSRs.
• \. Participants are willing and able to resume and tolerate Palynziq at the reactive dose prior to the RDD.
• \. Participant must not be receiving concurrent injectables containing PEG with the exception of PEG-containing vaccines, such as COVID-19 vaccinations (see Section 6.7).
• Participants receiving beta blockers.
• Prior/Concurrent Clinical Study Experience 8. Participants may not be currently participating in an interventional study of any investigational product, device, or procedure, or any other BioMarin clinical trial or post-marketing study.

Sponsors & Collaborators

• BioMarin Pharmaceutical: lead

Study Sites (1)

Uncommon Cures

Chevy Chase, Maryland, 20815, United States

Location

MeSH Terms

Conditions

Phenylketonurias

Condition Hierarchy (Ancestors)

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; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Officials

• Medical Director, MD

  BioMarin Pharmaceutical

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 13, 2025
• First Posted: January 17, 2025
• Study Start: February 7, 2025
• Primary Completion: August 17, 2026
• Study Completion: August 17, 2026
• Last Updated: October 1, 2026

Record last verified: 2026-09

Locations

US (1)