Recruiting
Phase 1
Phase 2

DYNE-101

Sponsor:

Dyne Therapeutics

Code:

NCT05481879

Conditions

Myotonic Dystrophy Type 1 (DM1)

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Interventions

DYNE-101

Placebo

Study Details

Brief summary:

The primary purpose of the study is to evaluate the safety and tolerability of multiple intravenous (IV) doses of DYNE-101 administered to participants with Myotonic Dystrophy Type 1 (DM1).

The study consists of 4 periods: A Screening Period (up to 8 weeks), a Placebo-Controlled Period (24 weeks), a Treatment Period (24 weeks) and a Long-Term Extension (LTE) Period (168 weeks) in both multiple-ascending dose (MAD) and dose expansion cohorts.

Conditions

Myotonic Dystrophy Type 1 (DM1)

Study ID

NCT05481879

Start date

Sep 5, 2022

Status verified date

Aug, 2025

Completion date

Jul, 2029

Anticipated

Primary completion date

Jul, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 65

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Diagnosis of DM1 with trinucleotide repeat size >100.
  • Age of onset of DM1 muscle symptoms ≥12 years.
  • Clinically apparent myotonia equivalent to hand opening time of at least 2 seconds in the opinion of the Investigator.
  • Hand grip strength and ankle dorsiflexion strength.
  • Able to complete 10-MWRT, stair ascend/descend (MAD cohorts only), and 5×STS at screening without the use of assistive devices such as canes, walkers, or orthoses.

Exclusion Criteria:

  • History of major surgical procedure within 12 weeks prior to the start of investigative product administration or an expectation of a major surgical procedure (eg, implantation of cardiac defibrillator) during the study.
  • History of anaphylaxis.
  • Medical condition other than DM1 that would significantly impact ambulation or participation in functional assessments.
  • Treatment with medications that can improve myotonia within a period of 5 half-lives of the medication prior to performing screening assessments.
  • Electrocardiogram (ECG) with the corrected QT interval by Fridericia's Formula (QTcF) ≥450 milliseconds (ms) in men and QTcF ≥460 ms in women, PR ≥240 ms, left bundle-branch block, or a conduction defect, which is clinically significant in the opinion of the Investigator.
  • Percent predicted forced vital capacity (FVC) <50%.
  • History of tibialis anterior biopsy within 3 months of Day 1 or planning to undergo tibialis anterior biopsies during study period for reasons unrelated to the study.
  • Participant has a history of suicide attempt, suicidal behavior, or has any suicidal ideation within 6 months prior to Screening that meets criteria at a level of 4 or 5 of the Columbia Suicide Severity Rating Scale (C-SSRS) or who, in the opinion of the Investigator, is at significant risk to commit suicide.
  • Use of glucagon-like peptide 1 (GLP-1) agonist medications including semaglutide, dulaglutide, liraglutide, exenatide, or tirzepatide within a period of 5 half-lives of the medication prior to performing screening assessments.
  • Significant weight loss during study participation may impact weight-based dosing, performance on muscle function assessments, and pharmacodynamic (PD) biomarkers.

Note: Other inclusion and exclusion criteria may apply.

Study Design

Enrollment

116 participants

Anticipated

Allocation

Randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: MAD Cohort: Placebo-Controlled Period: DYNE-101

Participants will be randomized to receive ascending doses of DYNE-101, once every 4 weeks (Q4W) or once every 8 weeks (Q8W) for up to 24 weeks.

placebo comparator: MAD Cohort: Placebo-Controlled Period: Placebo

Participants will be randomized to receive DYNE-101 matching placebo, Q4W or Q8W for up to 24 weeks.

experimental: MAD Cohort: Treatment Period: DYNE-101

Participants who receive DYNE-101 in Placebo-Controlled Period will continue to receive DYNE-101, Q4W or Q8W for up to 24 weeks.

Participants who receive placebo in Placebo-Controlled Period will receive DYNE-101, Q4W or Q8W for up to 24 weeks.

experimental: MAD Cohort: Long-Term Extension Period: DYNE-101

Participants will receive DYNE-101, Q4W or Q8W for up to 168 weeks.

experimental: Dose Expansion Cohort: Placebo-Controlled Period: DYNE-101

Participants will receive DYNE-101, Q8W for up to 24 weeks.

experimental: Dose Expansion Cohort: Placebo-Controlled Period: Placebo

Participants will receive DYNE-101 matching placebo, Q8W for up to 24 weeks.

experimental: Dose Expansion Cohort: Treatment Period: DYNE-101

Participants who receive DYNE-101 in Placebo-Controlled Period will continue to receive DYNE-101, Q8W for up to 24 weeks.

Participants who receive placebo in Placebo-Controlled Period will receive DYNE-101, Q8W for up to 24 weeks.

experimental: Dose Expansion Cohort: Long-Term Extension Period: DYNE-101

Participants will receive DYNE-101, Q8W for up to 168 weeks.

Interventions

DYNE-101

Administered by IV infusion

Placebo

Administered by IV infusion

Primary outcome measure

  • MAD Cohorts: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) [ Time Frame: Through study completion, up to Week 217 ]
  • Dose Expansion Cohorts: Change From Baseline in Myotonia as Measured by Video Hand Opening Time (vHOT) [ Time Frame: Baseline up to Week 25 ]

Central Contacts and Locations

Central contacts

Dyne Clinical Trials

+1-781-317-1919clinicaltrials@dyne-tx.com

Locations

Stanford University

Recruiting

Stanford, California, United States, 94305

Contacts

Lidia Choniawko

lidiacho@stanford.edu

Principal Investigator:

Dr. John Day, MD, PhD

University of Florida College of Medicine

Recruiting

Gainesville, Florida, United States, 32610

Contacts

Debbye Landers

debralanders@peds.ufl.edu

Principal Investigator:

Dr. Sub Subramony, MD

Indiana University School of Medicine

Recruiting

Indianapolis, Indiana, United States, 46202

Contacts

Patti Hogan, BSN RN, CCRA

hoganpr@iu.edu

Principal Investigator:

Laurie Gutmann, MD

University of Iowa

Recruiting

Iowa City, Iowa, United States, 52242

Contacts

Heena Olade, RN, MSN

heena-olalde@uiowa.edu

Principal Investigator:

Andrea Swenson, MD

Washington University in St. Louis

Recruiting

St Louis, Missouri, United States, 63110

Contacts

Natalie Goedeker

ngoedeker@wustl.edu

Principal Investigator:

Dr. Craig Zaidman, MD

University of Rochester Medical Center

Recruiting

Rochester, New York, United States, 14642

Contacts

Jim Hilbert

james_hilbert@urmc.rochester.edu

Principal Investigator:

Dr. Joahnna Hamel, MD

Neurology Rare Disease Center

Recruiting

Denton, Texas, United States, 76208

Contacts

Isabella Herman

Research@neuromdcenter.com

Principal Investigator:

Diana Castro, MD

Virginia Commonwealth University (VCU)

Recruiting

Richmond, Virginia, United States, 23298

Contacts

Jodie Howell

Jodie.howell@vcuhealth.org

Anarosa Rezeq

anarosa.rezeq@vcuhealth.org

Principal Investigator:

Nicholas Johnson, M.D., M.Sci., FAAN

More Information

Sponsor

Dyne Therapeutics

Last update posted

May 12, 2026

Last verified

Aug, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Dyne Therapeutics on 2026-05-12.