PhenylketonuriaPhase 4PALLADIUMNCT06780332
Rapid Drug Desensitization Study in Adults Experiencing Hypersensitivity Reactions to Palynziq
A Phase 4 study testing RDD to Palynziq in people with Phenylketonuria and PKU, run by BioMarin Pharmaceutical at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Phenylketonuria, PKU
- What is being tested?
- RDD to Palynziq
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 9 participants
- Where
- 1 siteUnited States
- Study dates
- 7 Feb 2025to 17 Aug 2026
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age:
- 1.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.
- 3. 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.
Who cannot join
- 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:
- 4. Participants were not using antihistamine premedication(s) at the time of reactive HSRs.
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- 5. Participants are willing and able to resume and tolerate Palynziq at the reactive dose prior to the RDD.
- 6. 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).
- 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.
- Other Exclusions 9. Participants must not be experiencing reactions that are not appropriate for RDD, including severe cutaneous adverse reactions (SCAR) as defined by the American Academy for Allergy, Asthma, and Immunology.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Phase 4 Study to Evaluate the Impact of a Rapid Drug Desensitization (RDD) Protocol for Adults With Phenylketonuria and Experiencing Hypersensitivity Reactions to Palynziq
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
Read the detailed description
This is a Phase 4 study to evaluate the impact of RDD on adult (≥18 years old) participants with PKU who have experienced HSRs leading to treatment interruption or reduction of dose or dosing frequency while receiving commercial Palynziq. This is not a blinded study. All participants will undergo the same assessments: Screening, the RDD in clinic on Day 1, in clinic dosing on Day 2, followed by remote visits in weeks 2-24 post-RDD to monitor for HSRs and changes in Palynziq dosing. Remote visits will occur every other week from Week 2 through Week 12, then monthly until Week 24.
The total duration of participation in the trial will be approximately 30 weeks: up to 6 weeks for screening, followed by RDD and 24 weeks of post-RDD follow-up.
No Data Monitoring Committee (DMC) will be used for this trial.
- Conditions
- Phenylketonuria, PKU
- Being tested
- RDD to Palynziq
- Keywords
- Phenylketonuria, PKU, Palynziq, pegvaliase
- Medical subject headings
- Phenylketonurias
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RDD to PalynziqDrug
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.
| Study group | Role | What they receive |
|---|---|---|
| RDD | Experimental | Participants undergoing RDD to Palynziq Receives: Drug: RDD to Palynziq |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 24 weeks
Secondary outcomes (1)
To characterize the immune response to Palynziq following RDD
Change in PEG IgG and IgM, PAL IgG and PAL IgM, and C3/C4 from Baseline to after RDD and at Week 24
Measured: 24 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Jan 2025
- Study start7 Feb 2025
- Primary completion17 Aug 2026
- Study completion17 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PhenylketonuriaStudies of the same condition, open and under way.
- More trials run by BioMarin PharmaceuticalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 9 participants (actual)
Sponsor and investigators
- Lead sponsor
- BioMarin Pharmaceutical
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, MD, Study director, BioMarin Pharmaceutical
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06780332
- Sponsor's protocol ID
- 165-402
- Acronym
- PALLADIUM
- Status last verified
- Sep 2026
- First submitted
- 13 Jan 2025
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 4 Study to Evaluate the Impact of a Rapid Drug Desensitization (RDD) Protocol for Adults With Phenylketonuria and Experiencing Hypersensitivity Reactions to Palynziq
- ClinicalTrials.gov ID
- NCT06780332
- Acronym / sponsor ID
- PALLADIUM / 165-402
- Conditions
- Phenylketonuria, PKU
- Keywords
- Phenylketonuria, PKU, Palynziq, pegvaliase
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 9 participants (actual)
- Lead sponsor
- BioMarin PharmaceuticalIndustry (pharma, biotech, devices)
- Study start
- 7 Feb 2025 (actual)
- Primary completion
- 17 Aug 2026 (actual)
- Study completion
- 17 Aug 2026 (actual)
- First posted
- 17 Jan 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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
Detailed description
This is a Phase 4 study to evaluate the impact of RDD on adult (≥18 years old) participants with PKU who have experienced HSRs leading to treatment interruption or reduction of dose or dosing frequency while receiving commercial Palynziq. This is not a blinded study. All participants will undergo the same assessments: Screening, the RDD in clinic on Day 1, in clinic dosing on Day 2, followed by remote visits in weeks 2-24 post-RDD to monitor for HSRs and changes in Palynziq dosing. Remote visits will occur every other week from Week 2 through Week 12, then monthly until Week 24.
The total duration of participation in the trial will be approximately 30 weeks: up to 6 weeks for screening, followed by RDD and 24 weeks of post-RDD follow-up.
No Data Monitoring Committee (DMC) will be used for this trial.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| RDD | Experimental | Drug: RDD to PalynziqParticipants undergoing RDD to Palynziq |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age:
- 1.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.
- 3. 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.
Key exclusion criteria (11 listed)
- Medical Conditions:
- Prior/Concomitant Therapies:
- 4. Participants were not using antihistamine premedication(s) at the time of reactive HSRs.
- 5. Participants are willing and able to resume and tolerate Palynziq at the reactive dose prior to the RDD.
- 6. 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RDD to PalynziqDelivery 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. | Drug | RDD |
Primary outcome
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).
Time frame: 24 weeks
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
1 secondary outcome
To characterize the immune response to Palynziq following RDD
Time frame: 24 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director, MD study director
BioMarin Pharmaceutical
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing RDD to Palynziq in people with Phenylketonuria and PKU, run by BioMarin Pharmaceutical at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). (time frame: 24 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Oct 2026.