Randomized, Placebo-Controlled, Multiple Ascending Dose Study Assessing Safety, Tolerability, Pharmacodynamics, Efficacy, and Pharmacokinetics of Dyne-101 Administered to Participants with Myotonic Dystrophy Type 1

Investigational Medication Study for Myotonic Dystrophy Type 1

L
Laurie Gutmann

Primary Investigator

Enrolling By Invitation
18 years - 65 years
All
Phase N/A
1 participants needed
1 Location

Brief description of study

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).

THIS STUDY IS ENROLLING BY INVITATION ONLY

Detailed description of study

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.

Eligibility of study

You may be eligible for this study if you meet the following criteria:

  • Conditions: Myotonic Dystrophy Type 1 (DM1)
  • Age: 18 years - 65 years
  • Gender: All

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.

This study investigates the effects of an investigational medication on individuals with Myotonic Dystrophy Type 1 (DM1). DM1 is a genetic disorder that affects muscle function, causing symptoms such as myotonia, which is a delayed relaxation of muscles after contraction. The purpose of this study is to assess the safety and tolerability of multiple doses of the investigational medication administered intravenously to participants with DM1.

Participants in the study will receive either the investigational medication or a placebo, which is an inactive substance that looks like the investigational medicine but does not contain any medicine. The study involves several periods, including a placebo-controlled period and a long-term extension period, to evaluate different dose levels and their effects on safety, pharmacodynamics, efficacy, and pharmacokinetics.

  • Who can participate: Participants must have a diagnosis of DM1 with a trinucleotide repeat size greater than 100, have experienced muscle symptoms since at least age 12, be able to perform certain physical tests without assistance, and have clinically apparent myotonia.
  • Study details: Participants will receive multiple intravenous doses of an investigational medication or a placebo. The study will assess the effects on muscle function and overall safety, including various assessment periods to monitor the participants' response to the treatment.
Updated on 17 Nov 2025. Study ID: NEUR-DYNE-ACHIEVE, 28197
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Interested in the study?

This study is accepting only persons who receive care at a certain clinic or doctor or who are part of an invited group. Questions about this study can be directed to the study team listed in the description or contact your doctor to see if you are eligible.

Accepting Referrals by Invitation Only