Safety, Tolerability, and Efficacy of PLX-200 in Patients With CLN3

August 17, 2026 updated by: Polaryx Therapeutics, Inc.

A Randomized. Multicenter, Double-Blind, Placebo-Controlled Safety, Tolerability, and Efficacy Study of PLX-200 in Participants With Mild-to-Moderate Juvenile Neuronal Ceroid Lipofuscinosis (CLN3) Disease

The purpose of this study is to evaluate the safety and efficacy of multiple doses of PLX-200 in patients with CLN3 disease.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Withdrawn

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a phase 3, double-blind, placebo-controlled, dose-titration study to evaluate escalating weight-based dose levels of PLX-200, provided as a solution that contains 15 mg/mL PLX-200 and administered orally using a syringe, as needed, twice daily (BID), 30 minutes before breakfast and dinner. Participants will enter the Titration Period, during which the starting dose of PLX-200 or placebo will be based on patient weight. Each patient's dose will be titrated upward on a weekly basis during the Titration Period, until he or she reaches a maximally tolerated dose (MTD) or the Week 5 dose for their weight category. The patient will then enter the Maintenance Period at the final Titration Period dose for a maximum of 60 weeks. Safety, efficacy, and pharmacokinetics will be assessed periodically. Thereafter, all patients will have the opportunity to receive active treatment in an Open-Label Extension (OLE) for an additional 36 weeks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

6 years to 18 years (Child, Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male and female participants between the ages of 6 and 18 years of age. Any deviations from this age range must be approved by the Medical Monitor and Sponsor prior to entry into study.
  2. Has a diagnosis of "classic" CLN3 disease as determined by age of symptom onset (i.e., 4 to 7 years) and genetic analysis for a defect in the CLN3 (battenin) transmembrane gene at study entry. If no genotype information is available, blood will be collected for the CLN3 gene analysis at the Screening visit.
  3. Participant must have mild-to-moderate CLN3 disease documented by a total in the 3-domain score of 5 to 7 for the aggregate of the motor, language, and vision domains of the Hamburg Scale and a score of at least 2 in 2 of these 3 domains.
  4. Participant must be able to independently walk for a distance of at least 20 feet (6 meters).
  5. Participant must be able to tolerate swallowing oral medication.
  6. Participants who are of childbearing potential (i.e., have begun menstruation) must have a negative serum pregnancy test at Baseline before receiving PLX-200. Nursing mothers are excluded from participation in this study.
  7. Participants' parents/guardians must agree to comply in good faith with the conditions of the study, including attending all required baseline and follow-up assessments.
  8. Participant parents and legal guardians must sign the informed consent form, and participants will provide assent, depending on local regulations and developmental status.

Exclusion Criteria:

  1. Participant has asymptomatic CLN3 disease, defined as no evidence of neurological signs or symptoms attributed to CLN3 disease such as seizures, ataxia, language delay, or other developmental delays. Similarly, outliers who progress much more slowly or quickly compared to the rest of the study population will be excluded from study at the discretion of the PI in consultation with the Medical Monitor (e.g., c.1A > C start codon mutation).
  2. Participant has clinically documented generalized motor status epilepticus within 4 weeks of the Baseline visit (treatment may be postponed after discussion with the Medical Monitor until seizures are adequately controlled).
  3. Participant has another inherited neurologic disease in addition to CLN3 disease.
  4. Participant has another neurological illness that may cause cognitive or motor decline.
  5. Participants with enteral feeding with NG tubing and any difficulty in oral administration and/or absorption of study drug will be excluded.
  6. Participant requires ventilation support, except for noninvasive support at night (e.g., Continuous Positive Airway Pressure [CPAP], Bilevel Positive Airway Pressure [BiPAP]).
  7. Participant has moderate or severe hepatic dysfunction defined as alanine aminotransferase, aspartate aminotransferase, or total bilirubin >3x upper limit of normal (ULN) except for participants with Gilbert syndrome. Participant has primary biliary cirrhosis.
  8. Participant has anemia (defined as hemoglobin <10 g/dL or hematocrit <30%).
  9. Participant has a baseline serum creatinine >2 mg/dL.
  10. Participant has gallbladder disease (e.g., cholelithiasis or cholecystitis).
  11. Participant has hypersensitivity to gemfibrozil.
  12. Participant is using or requires treatment with 1. HMG-CoA reductase inhibitors, 2. repaglinide (Prandin®), 3. dasabuvir (Exviera®), 4. selexipag (Uptravi®), or 5. pioglitazone (Actos®).
  13. Since the participant may take anticoagulants, increased frequency of INR monitoring is essential to avoid potential toxic effects with concurrent PLX-200 and anticoagulants (in particular with warfarin).
  14. Participant has a medical condition or personal circumstance that, in the opinion of the Investigator, might compromise the participant's or parent/guardian's ability to comply with the protocol requirements, or compromise the participant's wellbeing, safety, or the interpretability of the study data.
  15. Participant has received any investigational product or medical device within 30 days of the Baseline visit that, in the Investigator's judgment, would make the participant ineligible or confound results. All subjects who have had an investigational product or products in the form of stem cell or gene therapy are excluded, regardless of when the therapy had been initiated and/or discontinued.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: PLX-200
This is randomized, placebo-controlled comparator study of PLX-200 in patients with CLN3 disease.
Drug: PLX-200
15 mg/mL oral solution of experimental drug
Other Names:
  • Gemfibrozil
Placebo Comparator: Placebo
This is randomized comparator study of PLX-200 vs. placebo in a 2:1 ratio in patients with CLN3 disease.
Drug: Placebo
Taste and color-matched drug-free solution

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Efficacy of PLX-200 in CLN3 as assessed by the change in the motor score of the Hamburg Rating Scale compared with that of the Placebo group
Time Frame: 60 weeks
The change from baseline in the motor score of the Hamburg Rating Scale at Week 60 of maintenance therapy in participants treated with PLX-200 compared with that of Placebo group. Baseline is defined as the motor score of the Hamburg Rating Scale assessment prior to starting drug or Placebo group in the Titration Period. The Hamburg Rating Scale records a rating of 0 - 3 in four domains: motor skills, vision, language, and seizures, all from 0 - 3 which is worse to normal, respectively, with a minimum (worse) score of 0 to a maximum (normal) score of 12.
60 weeks
Number of patients with treatment-related adverse events, as assessed by CTCAE v5.0, abnormal laboratory results, and abnormal cardiovascular and/or abdominal findings.
Time Frame: 96 weeks
The aggregate of clinical chemistries, hematology, urinalysis, electrocardiogram readings, abdominal ultrasound findings, and tabulation of the number and severity of adverse events will be compared with baseline values throughout the study to evaluate the safety and tolerability of PLX-200 at escalating oral doses in children with CLN3 disease.
96 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Efficacy of PLX in each of the domains of the Hamburg Scale
Time Frame: 24, 48, 60, 72 and 96 weeks
Changes in the Baseline score of each of the 4 domains of the Hamburg Rating Scale (motor, language, visual, and seizures) at 24, 48, 60 (except motor score), 72, and 96 weeks of maintenance therapy in those treated with PLX-200 compared with those treated with Placebo. The Hamburg rating per domain is 0 - 3 with 3 representing worse outcomes.
24, 48, 60, 72 and 96 weeks
Assessment of the overall decline status in subjects treated with PLX-200 compared with the placebo group
Time Frame: 60 and 96 weeks
The overall decline status (Yes/No) at Maintenance Weeks 60 and 96 in subjects treated with PLX-200 compared to those treated with Placebo. A subject will be considered to have an overall decline if either (i) a decrease from baseline in any of the 4 domains (motor, language, visual, seizure) of the Hamburg rating scale is observed or (ii) the assessment is missing at the visit for any reason. The Hamburg rating per domain is 0 - 3 with 3 representing worse outcomes.
60 and 96 weeks
Evaluation of the baseline motor score decline between PLX-200 and placebo
Time Frame: 60 and 96 weeks
The Motor Score decline status (Yes/No) at Maintenance Weeks 60 and 96 in subjects treated with PLX-200 compared to those treated with Placebo using two alternative definitions. In Definition 1, a subject will be considered to have declined (i.e. worsened) if at least a one-point decrease from baseline in the motor score of the Hamburg scale is observed or if the visit is missing for any reason. In Definition 2, subjects with at least a 2-point decrease or if the visit is missing will be considered to have declined.
60 and 96 weeks
Assessment of changes in the baseline Clinical Impression of symptom severity between PLX-200 and Placebo groups
Time Frame: 24, 48, 60, 72, and 96 weeks
Changes from baseline in the Clinical Global Impression of symptom severity to 24, 48, 60, 72, and 96 weeks of maintenance therapy in those treated with PLX-200 compared with those treated with Placebo. The CGI severity scale (CGI-S) rates illness severity and the CGI-Improvement (CGI-I) which both rate on a scale of 1 - 7 which relates to improved/very much improved to worse disease.
24, 48, 60, 72, and 96 weeks
Assessment of changes in the baseline Pediatric Balance Scale between PLX-200 and Placebo groups
Time Frame: 24, 48, 60, 72, and 96 weeks
Change in the Pediatric Balance Scale (modified Berg Balance Scale) score from Baseline to 24, 48, 60, 72, and 96 weeks of maintenance therapy in those treated with PLX-200 compared with those treated with Placebo. The scale is age, weight, height, and gender specific but across all groups, the higher score between 0 - 4 represents better outcomes than 0 which is worse outcome.
24, 48, 60, 72, and 96 weeks
Assessment of changes in the baseline Montreal Assessment Cognitive Scale between PLX-200 and Placebo groups
Time Frame: 24, 48, 60, 72, and 96 weeks
Change in the Montreal Cognitive Assessment (MoCA) score from Baseline to 24, 48, 60, 72, and 96 weeks of maintenance therapy in those treated with PLX-200 compared with those treated with Placebo. The MoCA cutoff score of 26 differentiates youth with and without cognitive impairment with the lower score being considered increased cognitive impairment.
24, 48, 60, 72, and 96 weeks
Assessment of changes in the baseline Vineland Behavior Scale between PLX-200 and Placebo groups
Time Frame: 24, 48, 60, 72, and 96 weeks
Change in the Vineland Behavior Scale from Baseline to 24, 48, 60, 72, and 96 weeks of maintenance therapy in those treated with PLX-200 compared with those treated with Placebo. The Vineland Scale captures changes in intellectual and developmental disabilities. To date, there are no normal values determined for the Vineland Behavior Scale but the higher the score suggests greater capabilities.
24, 48, 60, 72, and 96 weeks
Assessment of changes in the baseline walking ability of the patient between PLX-200 and Placebo groups
Time Frame: 24, 48, 60, 72, and 96 weeks
Change in walking ability (6-minute walk test; 6MWT) from Baseline to weeks 24, 48, 60, 72, and 96 weeks of maintenance therapy in those treated with PLX-200 compared with those treated with Placebo. The 6MWT normal range is highly specific to the patient. Thus, all tests will be compared to the Baseline value during the Screening Phase.
24, 48, 60, 72, and 96 weeks
PLX-200 pharmacokinetics (PK) will be evaluated through periodic blood draws during the trial. PLX-200 levels will be determined to estimate area under the curve, maximal concentration, time to maximal concentration, half-life, and dosing interval
Time Frame: 96 weeks
To evaluate PLX-200 plasma concentrations in blood collected from participants during the Titration and Maintenance Periods for PK analyses, namely Cmax (maximal PLX-200 concentration) and Tmax (time to Cmax), elimination half-life (t1/2), area under the plasma concentration-time curve (AUC), and the dosing interval.
96 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Polaryx Therapeutics, Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Lisa Bollinger, MD, Chief Medical Officer

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 4, 2020

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 14, 2020

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 19, 2020

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PLX-200-002

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

None planned.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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