First-in-human Study of UX016 in GNEM

August 31, 2026 updated by: Ultragenyx Pharmaceutical Inc

A Phase 1/2, First-in-human, Double-blind, Placebo-controlled Study to Assess Dose, Safety, and Efficacy of UX016 (Sialic Acid-C16 Prodrug) in Adults With GNE Myopathy

The goal of this study is to assess the safety and dose of UX016 and its impact on muscle strength in adults with GNE Myopathy (GNEM).

Study Overview

Status

Status

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

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.

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

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
24

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 2
  • Phase 1

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.

Study Contact Backup

Study Locations

  • United States
    • California
      • Orange, California, United States, 92868
        • Not yet recruiting
        • Clinical Trial Site
    • New Jersey
      • Iselin, New Jersey, United States, 08830
        • Recruiting
        • Rare Disease Research

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

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • A confirmed diagnosis of GNEM (also known as distal myopathy with rimmed vacuoles [DMRV], hereditary inclusion body myopathy [HIBM], inclusion body myopathy 2 [IBM2], and Nonaka myopathy in Japan) by Clinical Laboratory Improvement Amendments (CLIA)-certified genetic testing with identification of a disease-associated variant in the gene encoding the GNE/MNK enzyme. Genotyping will not be conducted in this protocol
  • Ability to walk a minimum of 20 m independently during Screening. The use of assistive devices and orthotics is allowed.
  • Has ≤ 80% of normal biceps strength (dominant side) assessed by hand-held dynamometry (HHD) associated with a clinical pattern of weakening in the upper extremity and ability to provide reproducible force in unilateral elbow flexors (dominant side) during HHD testing (unilateral between test variability of ≤ 15%) during Screening.
  • Willing and able to comply with all study procedures including needle muscle biopsies of the quadriceps muscle.
  • From informed consent to after the last dose of study drug, females of childbearing potential and fertile males must consent to use highly effective contraception. If female, agree not to become pregnant and willing to have additional pregnancy testing during the study. Females considered not of childbearing potential include those who have been in menopause for at least 2 years, have had tubal ligation at least 1 year prior to Screening, or who have had a total hysterectomy. If male, agree not to father a child or donate sperm.
  • Provide informed consent after the nature of the study has been explained and prior to any research-related procedures.

Exclusion Criteria:

  • Ingestion of N-acetyl-D-mannosamine (ManNAc), SA, or related metabolites, including 6-sialyllactose; intravenous immune globulin; supplements; or anything that can be metabolized to produce significant amounts of SA in the body for the prior 60 days through the end of the study.
  • Any changes in diet or exercise routine in the prior 30 days. Subjects are strongly discouraged from making any changes to their diet and exercise routines following enrollment.
  • Receiving concomitant oral medications that are substrates for CYP2B6, P-glycoprotein (P-gp) transporters, or breast cancer resistance protein (BCRP) transporters.
  • Known hypersensitivity to SA or its excipients that, in the judgment of the Investigator, places the subject at increased risk for adverse effects.

  • Any of the following laboratory abnormalities at Screening:

    • Alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), or glutamate dehydrogenase (GLDH) > 3 × upper limit of normal (ULN)
    • Total bilirubin > 2 × ULN
  • Estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 based on cystatin C.
  • Men with a Fridericia-corrected QT interval (QTcF) > 450 msec and women with a QTcF > 460 msec at Screening.
  • Presence or history of any condition, laboratory abnormality, or infection that, in the Investigator's judgment, would interfere with participation, pose undue safety risk, or confound interpretation of study results.
  • Pregnant or breastfeeding at Screening or planning to become pregnant (self or partner) at any time during the study.
  • Use of any investigational product or investigational medical device within 30 days prior to Screening or requirement for any investigational agent prior to completion of all scheduled study assessments.

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: Sequential 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: 1g UX016 -> Extension Period
Participants will be randomized 3:1 to receive UX016 or placebo. Depending on sub-cohort assignment, participants may receive two single doses of UX016 (0.5g and 1g) or one single dose (1g) before starting daily dosing, or they may proceed directly to daily dosing at the assigned 1g dose level. After completing 48 weeks of daily dosing, participants will be eligible to enter the Extension Period, during which all participants will receive UX016.
Drug: UX016
Tablets for oral use
Experimental: 2g UX016 -> Extension Period
Participants will be randomized 3:1 to receive UX016 or placebo. Depending on sub-cohort assignment, participants may receive a single dose of UX016 (2g) before starting daily dosing, or they may proceed directly to daily dosing at the assigned 2g dose level. After 48 weeks of daily dosing, participants will be eligible to enter the Extension Period, during which all participants will receive UX016.
Drug: UX016
Tablets for oral use
Placebo Comparator: Placebo -> Extension Period
Participants will be randomized 3:1 to receive UX016 or placebo. Depending on sub-cohort assignment, participants may receive one or more single doses of placebo before starting daily dosing or they may proceed directly to daily dosing of placebo at the assigned dose level. After 48 weeks of daily dosing of placebo, participants will be eligible to enter the Extension Period, during which all participants will receive UX016.
Drug: UX016
Tablets for oral use
Other: Placebo
Tablets for oral use. Tablets will match the UX016 tablets, but contain no active ingredients

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
Time Frame
Upper Extremity Composite (UEC) Score Change From Baseline
Time Frame: Baseline, 48 Weeks
Baseline, 48 Weeks
Number of Participants with Treatment-Emergent Adverse Events (TEAEs)
Time Frame: Up to Week 96 (Double Blind and Extension Periods)
Up to Week 96 (Double Blind and Extension Periods)

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
Time Frame
Lower Extremity Composite (LEC) Score Change From Baseline
Time Frame: Baseline, 48 Weeks
Baseline, 48 Weeks
6-Minute Walk Test (6MWT) Change From Baseline
Time Frame: Baseline, 48 Weeks
Baseline, 48 Weeks
GNEM Functional Activities Scale (GNEM-FAS) Change From Baseline
Time Frame: Baseline, 48 Weeks
Baseline, 48 Weeks
Plasma Area Under the Curve (AUC) of UX016 and Free Sialic Acid (SA)
Time Frame: Baseline, 12 Weeks
Baseline, 12 Weeks
Plasma Maximum Concentration (Cmax) of UX016 and SA
Time Frame: Baseline, 12 Weeks
Baseline, 12 Weeks
Excretion in Urine of UX016 and SA
Time Frame: Baseline, 12 Weeks
Baseline, 12 Weeks
Free, Total, and Calculated Bound Sialic Acid (SA) in Muscle (Quadriceps) Change From Baseline
Time Frame: Baseline, 12 Weeks
Baseline, 12 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.
Ultragenyx Pharmaceutical 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: Medical Director, Ultragenyx Pharmaceutical Inc

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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.
October 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 1, 2028

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 1, 2028

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).
March 30, 2026

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.
March 30, 2026

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.
April 6, 2026

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.
September 3, 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 31, 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.
August 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.
  • UX016-CL210

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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