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RecruitingNCT07486934Updated Nov 6, 2026

Efficacy, Safety, and Tolerability of Zeleciment Basivarsen (DYNE-101) in Participants With Myotonic Dystrophy Type 1

A Phase 3 interventional study of zeleciment basivarsen (DYNE-101) and Placebo in Myotonic Dystrophy Type 1 (DM1), DM1 and Myotonic Dystrophy, sponsored by Dyne Therapeutics. Recruiting at 44 sites in 12 countries. Open to participants aged 16 Years and older. Per ClinicalTrials.gov, last updated 2026-11-06.

Sponsored by Dyne Therapeutics · Phase 3, Interventional, and Treatment

From the registry’s dates

  • Started May 2026; still recruiting 5 months later.
Updated Nov 6, 2026First site in New Zealand7 sites addedGo to Updates ↓
Phase
Phase 3
Study type
Interventional
Enrollment
150
Allocation
Randomized
Ages
16 Years and older
Sex
All
01

Study summary

The purpose of the study is to assess the efficacy, safety, and tolerability of zeleciment basivarsen (DYNE-101) for the treatment of myotonic dystrophy 1 (DM1).

Read the detailed description

The study consists of three periods: a Screening period (up to 8 weeks), Placebo-Controlled Period (48 weeks) and a Long-Term Extension Period (24 weeks).

An Independent Data Monitoring Committee (IDMC) comprised of members independent and external to the Sponsor will review safety and tolerability data of this study at regular intervals.

02

Conditions studied

  • Myotonic Dystrophy Type 1 (DM1)
  • DM1
  • Myotonic Dystrophy
  • Steinert Disease
  • Steinert

Keywords

  • DM1
  • Myotonic Dystrophy
  • Myotonic Dystrophy 1
  • Myotonia
  • Myotonic Dystrophy Type 1 (DM1)
  • Dystrophy Myotonic
  • Myotonic Disorders
  • Steinert Disease
  • Steinert
  • Myotonic Muscular Dystrophy
  • HARMONIA
  • Dyne Therapeutics
  • Dyne
  • DYNE-101
  • zeleciment basivarsen
  • z-basivarsen
03

In context

Myotonic Dystrophy

126 studies on the registry are indexed under Myotonic Dystrophy; 50 are open to participants now.

This study's planned enrollment of 150 is above the median of 40 across 67 interventional studies indexed under Myotonic Dystrophy.

Browse Myotonic Dystrophy studies →

Lead sponsor

Dyne Therapeutics is the lead sponsor of 4 studies on the registry; 2 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
16 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Diagnosis of DM1 confirmed by molecular genetics with trinucleotide repeat size greater than (>) 100. Historical results from clinical testing are acceptable.
  • Able to walk 10 meters and complete 5 times sit to stand independently (inserts or supports that don't go above the ankle are allowed).
  • (BMI) less than (\<) 35 kilograms per meter square (kg/m\^2).

Exclusion criteria

Exclusion Criteria:

  • A known diagnosis of congenital DM1.
  • History of major surgical procedure (based on Investigator judgment) within 12 weeks prior to the start of screening, with the exception of implanted pacemaker or defibrillator.
  • Use of glucagon-like peptide 1 (GLP-1) agonist/incretin medications including semaglutide, dulaglutide, liraglutide, exenatide, or tirzepatide within a period of 5 half-lives of the medication prior to performing screening assessments.

Note: Other inclusion and exclusion criteria may apply.

Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
150 participants (estimated)

Study arms

  • Experimental
    Placebo-Controlled Period: DYNE-101

    Participants will be randomized to receive DYNE-101, once every 8 weeks (Q8W) for up to 48 weeks.

    Drug: zeleciment basivarsen (DYNE-101)

  • Placebo comparator
    Placebo-Controlled Period: Placebo

    Participants will be randomized to receive DYNE-101 matching placebo, Q8W for up to 48 weeks.

    Drug: Placebo

  • Experimental
    Long-Term Extension Period: DYNE-101

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

    Drug: zeleciment basivarsen (DYNE-101) · Drug: Placebo

Interventions

  • Drugzeleciment basivarsen (DYNE-101)

    Administered by IV infusion

  • DrugPlacebo

    Administered by IV infusion

06

What researchers measure

Primary outcomes

  1. 5 Times Sit-To-Stand (5×STS) Time

    Time frame: Baseline, Week 49

Secondary outcomes

  1. Video Hand Opening Time (vHOT) [Middle Finger]

    Time frame: Baseline, Week 49

  2. Quantitative Muscle Testing (QMT) Total

    Time frame: Baseline, Week 49

  3. Clinician Global Impression of Change (CGI-C)

    Time frame: Week 49

  4. 10-Meter Walk/Run Test (10-MWRT) Velocity (m/s)

    Time frame: Baseline, Week 49

  5. Patient Global Impression of Change (PGI-C)

    Time frame: Week 49

  6. DM1-ACTIV^C Total Score

    Time frame: Baseline, Week 49

  7. Myotonic Dystrophy Health Index (MDHI) Total

    Time frame: Baseline, Week 49

  8. Patient Global Impression of Severity (PGI-S)

    Time frame: Baseline, Week 49

  9. Clinician Global Impression of Severity (CGI-S)

    Time frame: Baseline, Week 49

  10. 9-Hole Peg Test (9-HPT) Time

    Time frame: Baseline, Week 49

  11. Myotonic Dystrophy Health Index (MDHI) Subscale Scores

    Time frame: Baseline, Week 49

  12. Maximum Observed Plasma Drug Concentration (Cmax) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  13. Time to Maximum Concentration (tmax) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  14. Area Under the Concentration-Time Curve (AUC) from Hour 0 to the Last Measurable Concentration (AUC0-tlast) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  15. Area Under the Concentration-Time Curve Extrapolated to Infinity (AUC0-∞) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  16. Apparent Terminal Elimination Rate Constant (λZ) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  17. Apparent Terminal Elimination Half-Life (t½) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  18. Plasma clearance (CL) of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  19. Volume of Distribution at the Terminal Phase (Vz), if Appropriate of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  20. Volume of Distribution at Steady State (Vss), if Appropriate of DYNE-101

    Time frame: Pre-dose, and at multiple time points up to Week 73

  21. Number of Participants With Antidrug Antibodies (ADAs)

    Time frame: Up to Week 73

Other outcomes

  1. Fatigue and Daytime Sleepiness Scale (FDSS)

    Time frame: Up to Week 73

  2. Cognitive function as measured by individual and composite Cogstate cognition scores

    Time frame: Up to Week 73

  3. Digital functional assessments as measured by the ActiGraph LEAP® wearable device

    Time frame: Up to Week 73

07

Study locations

44 of 44 sites recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

5 registry updates since Sep 25, 2026
Sites
7 sites added — first site in New Zealand
Show 7 added (4 United States, 1 Germany, 1 Spain, 1 New Zealand)
  • University of Rochester Medical Center · Rochester, United States
  • Universitätsmedizin Göttingen · Göttingen, Germany
  • Houston Methodist Neurological Institute · Houston, United States
  • UF Health: University of Florida Clinical Research Center · Gainesville, United States
  • Kennedy Krieger Institute · Baltimore, United States
  • Hospital Universitari Vall d'Hebron · Barcelona, Spain
  • University of Auckland · Auckland, New Zealand
across 5 updates, Sep 25, 2026 – Nov 6, 2026
Show all 5 updates
  1. Nov 6, 2026
    1 site added — first site in New Zealand
    Show site
    • University of Auckland · Auckland, New Zealand
  2. Oct 13, 2026
    1 site added
    Show site
    • Hospital Universitari Vall d'Hebron · Barcelona, Spain
  3. Oct 5, 2026
    2 sites added
    Show 2 added (2 United States)
    • UF Health: University of Florida Clinical Research Center · Gainesville, United States
    • Kennedy Krieger Institute · Baltimore, United States
  4. Oct 1, 2026
    1 site added
    Show site
    • Houston Methodist Neurological Institute · Houston, United States
  5. Sep 25, 2026
    2 sites added
    Show 2 added (1 United States, 1 Germany)
    • University of Rochester Medical Center · Rochester, United States
    • Universitätsmedizin Göttingen · Göttingen, Germany

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07486934
Lead sponsor
Dyne Therapeutics
Responsible party
Sponsor
First posted
Mar 23, 2026
Start date
May 14, 2026
Primary completion
Jul 2028 (estimated)
Completion
Jan 2029 (estimated)
Last update
Nov 6, 2026

Study contacts

Dyne Clinical Trials
Contact
clinicaltrials@dyne-tx.com
+1-781-317-1919

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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