Recruiting
Phase 1
Phase 2

UX016

Sponsor:

Ultragenyx Pharmaceutical Inc

Code:

NCT07511556

Conditions

GNE Myopathy

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Not accepted

Interventions

UX016

Placebo

Study Details

Brief summary:

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).

Conditions

GNE Myopathy

Study ID

NCT07511556

Start date

Oct, 2026

Status verified date

Aug, 2026

Completion date

Dec, 2028

Anticipated

Primary completion date

Dec, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 55

Healthy Volunteers: Not accepted

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 Design

Enrollment

24 participants

Anticipated

Allocation

Randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

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.

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.

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.

Interventions

UX016

Tablets for oral use

Placebo

Tablets for oral use. Tablets will match the UX016 tablets, but contain no active ingredients

Primary outcome measure

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

Central Contacts and Locations

Central contacts

Patient Contact: Trial Recruitment

1-888-756-8657TrialRecruitment@ultragenyx.com

HCP Contact: Medical Information

1-888-756-8657medinfo@ultragenyx.com

Locations

Rare Disease Research

Recruiting

Iselin, New Jersey, United States, 08830

More Information

Sponsor

Ultragenyx Pharmaceutical Inc

Last update posted

Sep 3, 2026

Last verified

Aug, 2026

Keywords

  • GNEM
  • Hereditary Inclusion Body Myopathy (HIBM)
  • Distal Myopathy with Rimmed Vacuoles (DMRV)
  • Inclusion Body Myopathy 2 (IBM2)
  • Nonaka Myopathy

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Ultragenyx Pharmaceutical Inc on 2026-09-03.