Assessing the Safety and Tolerability of NMN in DHDDS-CDG

June 18, 2026 updated by: Eva Morava-Kozicz

Small Cohort, Off Label Treatment Assessing the Safety and Tolerability of NMN in DHDDS-Congenital Disorder of Glycosylation (DHDDS-CDG)

The primary objective of this study is to evaluate the safety and tolerability of the dietary supplement, nicotinamide mononucleotide (NMN), in individuals with dehydrodolichol diphosphate synthase congenital disorder of glycosylation (DHDDS-CDG). This will to contribute to knowledge that will allow healthcare providers to make informed decisions about recommending this dietary supplement in this population.

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.

Detailed Description

This is a small cohort, off label treatment study assessing the safety, and tolerability of the over-the-counter supplement, nicotinamide mononucleotide (NMN) in individuals with heterozygous DHDDS-CDG. There is no treatment currently available for this progressive disease and there is evidence that this supplement may be a viable supportive therapy. This study will assess the safety and tolerability of this supplement, as well as examine NMN's effect on clinical manifestations of DHDDS-CDG, including gait abnormalities and hand tremor. This phase 1, open-label study will have a 4 week run-in period, a treatment period of 6 months during which the participants will take 250 mg NMN daily, and an optional extension period of 6 more months. Study assessments will involve physician assessments, lab tests, physical exams, vital signs, height/weight measurements, participant goal-setting, and tests to assess gait performance and hand tremor.

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.
8

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 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 Locations

  • United States
    • New York
      • New York, New York, United States, 10029
        • Recruiting
        • Icahn School of Medicine at Mount Sinai
        • Contact:
        • Principal Investigator:
          • Eva Morava

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

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Subject is ≥ 4 years old
  • Subject has biologically and genetically proven heterozygous DHDDS-CDG.
  • Subject/legally authorized representative (LAR) is able to understand and provide written informed consent, and assent (as applicable) to participate in this study.

Exclusion Criteria:

  • Subject has intellectual disability with IQ<52 (moderate or lower IQ intellectual disability).
  • In the site Principal Investigator's opinion, subject has a history of intolerance to NMN or other niacin metabolite supplement that precludes the subject from participation in this study.

  • Subject has any of the following:

    • Liver failure
    • ALT level >5x ULN
    • AST level >5x ULN
    • eGFR < 30 OR creatinine >180 mmol/L
  • Subject is pregnant.
  • Use of investigational compounds within the previous 6 months or current enrollment in another trial involving investigational compounds.

  • Concomitant use of the following medications that could interact with orally administered NMN:

    • Aspirin
    • Metformin
    • Statins or other cholesterol-lowering drugs
  • In the site Principal Investigator's opinion, subject is not able or willing to comply with the trial requirements.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

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: nicotinamide mononucleotide (NMN)
Participants will take 250mg NMN daily.
Drug: Nicotinamide Mononucleotide (NMN) Nucleosidase

Name: nicotinamide mononucleotide (NMN)

Form: measured powder

Dose: 250 mg/day

Frequency: Daily

Route of administration: Oral

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
Incidence of adverse events (AEs)
Time Frame: up to 12 months
Incidence of AEs will be collected throughout the treatment period and optional long-term safety follow up period.
up to 12 months

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
International Cooperative Ataxia Rating Scale (ICARS) Score
Time Frame: Baseline, 6 months, 12 months
Change in ICARS score from baseline to end of the treatment period (6 months) and long term follow up (12 months). The minimal score is 0 and the maximum score is 100, with a higher score indicating greater impairment as a result of ataxia.
Baseline, 6 months, 12 months
Composite gait stability score (Cord walking test performance)
Time Frame: Baseline, 6 months, 12 months
Cord walking performance will be quantified using a standardized video-based computer vision pipeline applied to semi-structured recordings of participants walking along a straight line. Markerless pose estimation algorithms will extract time-resolved body keypoints, from which predefined gait and postural metrics will be derived, including step width variability, step length consistency, lateral deviation from the walking path, and trunk instability (e.g., standard deviation of body lean). Each metric will be summarized per recording and combined into a composite gait stability score using a prespecified algorithm. Change from baseline to 6 and 12 months will be calculated as within-subject differences in these quantitative measures, enabling objective assessment of gait abnormalities over time.
Baseline, 6 months, 12 months
Composite tremor severity score (Archimedes spiral test performance)
Time Frame: Baseline, 6 months, 12 months
Archimedes spiral test performance will be quantified using standardized digital analysis of recorded spiral drawings. Video or image inputs will be processed to extract the drawn trajectory, and quantitative features of tremor and motor control will be computed, including line deviation from an ideal spiral template, tremor amplitude (spatial variability), frequency of oscillations, and drawing smoothness (e.g., velocity and jerk metrics). These features will be aggregated into a composite tremor severity score using a predefined scoring framework. Change from baseline to 6 and 12 months will be assessed as within-subject differences in these quantitative metrics, providing an objective measure of hand tremor severity and progression.
Baseline, 6 months, 12 months

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.
Eva Morava-Kozicz

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.
  • Principal Investigator: Eva Morava, MD, PhD, Icahn School of Medicine at Mount Sinai

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 (Actual)

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.
May 8, 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.
August 1, 2027

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.
August 1, 2027

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).
May 1, 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.
May 1, 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.
May 7, 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.
June 22, 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.
June 18, 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.
June 1, 2026

More Information

Terms related to this study

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.
  • STUDY-25-01520

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

As this is an ultra rare disease, sharing IPD would involve risk of identification of participants.

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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