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PhenylketonuriaPRISM303NCT02468570

A Phase 3 Substudy to Evaluate Executive Function in Adults With PKU Who Are Participating in the Phase 3 Study, 165-302

An observational study of Phenylketonuria, run by BioMarin Pharmaceutical at 4 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

A Phase 3 substudy to evaluate executive function in adults with phenylketonuria who are participating in the phase 3 Study, 165-302. Approximately 100 subjects, aged ≥ 18 to ≤ 70 years old, with PKU will be enrolled. Read more about this study

Who is it for?
Ages 18 to 70 years
Conditions the study is for
Phenylketonuria
What is being tested?
Administration of CANTAB and Subject Global Assessment
How many people
9 participants
Where
4 sitesUnited States
Study dates
5 Aug 2015to 1 Feb 2017
Phase
Observational
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: Subjects with PKU who are currently enrolled in 165-302 Part 2.

Who may be able to join

  • Are currently participating in Part 1 of Study 165-302 and meet the criteria for participation in Part 2 of 165-302
  • Are willing and able to provide written, signed informed consent after the nature of the study has been explained and prior to any research-related procedures.
  • Have the ability to complete the CANTAB and subject global assessment.
  • Are willing and able to comply with all study procedures.

Who cannot join

  • Any condition that, in the view of the investigator, places the subject at high risk of poor compliance or terminating early from the study

Trial locations and contacts

4 sites in 1 country.

United States4 sites
  • University of Kentucky Medical Center

    Lexington, Kentucky, 40536

  • University of Oklahoma Health Sciences Center

    Oklahoma City, Oklahoma, 73104

  • University of Nebraska Medical Center

    Omaha, Nebraska, 68198

  • Oregon Health and Science University

    Portland, Oregon, 97239

Other trials in United States

About this study

Official title: A Phase 3 Substudy to Evaluate Executive Function in Adults With Phenylketonuria Who Are Participating in the Phase 3 Study, 165-302

A Phase 3 substudy to evaluate executive function in adults with phenylketonuria who are participating in the phase 3 Study, 165-302. Approximately 100 subjects, aged ≥ 18 to ≤ 70 years old, with PKU will be enrolled.

Read the detailed description

Study 165-303, is a Phase 3 substudy enrolling approximately 100 subjects, aged ≥ 18 to ≤ 70 years old, with PKU who are participating in the Phase 3 study, 165-302.

Per the 165-303 protocol, the investigator does not assign a specific intervention to the study participants. In accordance with the protocol for Study 165-303, subjects were asked to perform selected set of three tasks from the CANTAB tool (Rapid Visual Processing [RVP], Spatial Working Memory [SWM], and Stop Signal Task [SST]) to assess executive function and each subject's self perception of their current state was measured using a subject global assessment questionnaire that contains seven questions about current state perception of attention, energy level, tiredness, confusion, sadness, anger and tension.

The time points for administering the above tools are as follows, which coincide with time points in part 2 and part 4 of Study 165-302: screening (entry into Part 2 165-302 Day 1 of Week 1), baseline visit (Part 2 Week 8), and 3 additional study visits at different time points in the Part 4 of 165-302 study.

Conditions
Phenylketonuria
Being tested
Administration of CANTAB and Subject Global Assessment
Keywords
PKU, PEG-PAL, Pegvaliase, BMN 165, rAv-PAL PEG, PRISM 302, PRISM 303, BioMarin, 165-302
Medical subject headings
Phenylketonurias

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Administration of CANTAB and Subject Global AssessmentOther

    At designated visits, subject will perform the CANTAB tasks and complete the Subject Global Assessment Questionnaire

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change From Baseline in Rapid Visual Processing (RVP) Mean Response Latency (CANTAB Task)

    The RVP task measures sustained attention. In this task, a series of random digits continuously appears in the middle of the screen. Subjects are asked to recognize a specific sequence of digits and are asked to press a button on the screen whenever this specific sequence of digits appears within this series of continuous digits.

    RVP mean latency is the mean response latency during assessment sequence blocks where the subject responded correctly (Latency units are milliseconds). Lower scores represent better performance.

    Observed range for Pooled Active: -103.1 to 65.5 (change from baseline) Observed range for Pooled Placebo: -10.4 to 39.0 (change from baseline)

    Measured: Baseline to Part 2 Week 8

  2. Change From Baseline in Spatial Working Memory (SWM) Between Errors 4-8 Boxes (CANTAB Task)

    The SWM task measures visuospatial working memory. During this task, a number of boxes appears on a screen. The objective of the task is to find a token under a box and to place this token in a designated area. There is only one token under one box during each round and the location of the token rotates in each round to a different box, other than a box within which the token was found in previous rounds. The subject is therefore asked to remember which boxes previously contained tokens so as to better the chances and speed of finding tokens under boxes which did not previously contain tokens.

    SWM between errors measures the total number of times the subject revisits a box in which a token has previously been found in the same problem (calculated for assessed problems only).

    Observed range for Pooled Active: -8 to 1 (change from baseline) Observed range for Pooled Placebo: -5 to 12 (change from baseline)

    Lower scores represent better performance.

    Measured: Baseline to Part 2 Week 8

  3. Change From Baseline in Stop Signal Task (SST) Stop Signal Reaction T (CANTAB Task)

    The SST task measures inhibitory control and cognitive flexibility. The SST is a 2-part task. During part 1, an arrow appears on the screen and subjects are asked to press an arrow button on the screen corresponding with the direction of the arrow displayed. During part 2 of the task, subjects follow the same instructions as in part 1; however, they are asked to withhold their response (do not press an arrow button) if they hear an auditory signal (beep) when the arrow is displayed.

    SST stop signal delay is the length of time between the go stimulus and the stop stimulus at which the subject is able to successfully inhibit their response on 50% of trials. Lower time represents better performance.

    Observed range for Pooled Active: -31.6 to 48.7 (change from baseline) Observed range for Pooled Placebo: 47.8 to 72.5 (change from baseline)

    Measured: Baseline to Part 2 Week 8

Secondary outcomes (3)
  1. Change From Baseline in RVP A Prime - Signal Detection Measure of Sensitivity to the Target (CANTAB Task)

    The RVP task measures sustained attention. In this task, a series of random digits continuously appears in the middle of the screen. Subjects are asked to recognize a specific sequence of digits and are asked to press a button on the screen whenever this specific sequence of digits appears within this series of continuous digits.

    RVP A prime represents the signal detection measure of sensitivity to the target, regardless of response tendency. In essence, measure of how good the subject is at detecting target sequences.

    Observed range for Pooled Active: -0.004 to 0.030 (change from baseline) Observed range for Pooled Placebo: -0.057 to -0.001 (change from baseline)

    A higher score on the test represents a better performance.

    Measured: Baseline to Part 2 Week 8

  2. Change From the Baseline in SWM Strategy 6-8 Boxes - Number of Distinct Boxes Used by the Subject to Begin a New Search for a Token(CANTAB Task)

    The SWM task measures visuospatial working memory. During this task, a number of boxes appears on a screen. The objective of the task is to find a token under a box and to place this token in a designated area. There is only one token under one box during each round and the location of the token rotates in each round to a different box, other than a box within which the token was found in previous rounds. The subject is therefore asked to remember which boxes previously contained tokens so as to better the chances and speed of finding tokens under boxes which did not previously contain tokens.

    For assessed problems with six boxes or more, SWM strategy is the number of distinct boxes used by the subject to begin a new search for a token (within the same problem). A high score represents poor use of this strategy and a low score equates to effective use.

    Observed range for Pooled Active: -3 to 3 (change from baseline) Observed range for Pooled Placebo: -3 to 1(change from baseline)

    Measured: Baseline to Part 2 Week 8

  3. Change From Baseline in SST Proportion of Successful Stops - Measures the Proportion of Completed Stop Trials That Were Successful Stops (CANTAB Task)

    The SST task measures inhibitory control and cognitive flexibility. The SST is a 2-part task. During part 1, an arrow appears on the screen and subjects are asked to press an arrow button on the screen corresponding with the direction of the arrow displayed. During part 2 of the task, subjects follow the same instructions as in part 1; however, they are asked to withhold their response (do not press an arrow button) if they hear an auditory signal (beep) when the arrow is displayed. SST stop signal delay is the length of time between the go stimulus and the stop stimulus at which the subject is able to successfully inhibit their response on 50% of trials.

    SST proportion of successful stops measures the proportion of completed stop trials that were successful stops. A higher score on the test represents a better performance.

    Observed range for Pooled Active: -0.1 to 0.05 (change from baseline) Observed range for Pooled Placebo: 0.0 to 0.0 (change from baseline)

    Measured: Baseline to Part 2 Week 8

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 Jun 2015 (estimated)
  2. Study start5 Aug 2015
  3. Primary completion1 Feb 2017
  4. Study completion1 Feb 2017

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
9 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02468570
Sponsor's protocol ID
165-303
Acronym
PRISM303
Status last verified
May 2020
First submitted
3 Jun 2015
Last updated
4 Jun 2020
Data monitoring committee
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

An observational study of Phenylketonuria, run by BioMarin Pharmaceutical at 4 sites 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 4 inclusion and 1 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 4 Jun 2020. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites 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.

Are results available for this study?

Yes. Results are posted in the registry (first posted 4 Jun 2020). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Change From Baseline in Rapid Visual Processing (RVP) Mean Response Latency (CANTAB Task) (time frame: Baseline to Part 2 Week 8). The study lists 3 primary outcomes in all. 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 4 Jun 2020.

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