Early Phase Human Drug Trial to Investigate Dynamin 101 (DYN101) in Patients ≥ 16 Years With Centronuclear Myopathies

There are no available treatments aside from supportive care for patients with Centronuclear myopathy (CNM). This trial will assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD)/preliminary efficacy of a new medicine called DYN101 in patients ≥ 16 years of age with CNM caused by mutations in Dynamin2 (DNM2) or Myotubularin1 (MTM1). The trial will consist of a consent, a screening period, a run-in period (if applicable), a Single dose treatment part (SAD) with 4 weeks of follow-up after the drug administration and a washout period of at least 12 weeks (followed by follow-up phone calls), a Multiple dose treatment part (MAD) of 12 weeks of weekly dosing, and a Multiple dose extension part of 12 weeks. All subjects will participate in the SAD, MAD, and MAD extension parts, unless they withdraw. During this time, multiple test will be performed in order to better understand how the drug is distributed and then later removed from the body and whether there any signs of an effect. As this trial is investigational, there is no defined, expected benefit for subjects who participate in this trial except a better knowledge of their disease.

There are currently no available treatments aside from supportive care for patients with Centronuclear myopathy (CNM). This trial will assess the safety, tolerability, PK and PD/preliminary efficacy of DYN101 in patients ≥ 16 years of age with CNM caused by mutations in DNM2 or MTM1. DYN101 is a synthetically manufactured constrained ethyl gapmer antisense oligonucleotide (ASO) directed against DNM2 pre-messenger ribonucleic acid (mRNA). DYN101 will be provided as a sterile concentrated solution for reconstitution into an infusion solution for intravenous (IV) administration, and will be diluted into a 0.9% sodium chloride solution before administration. The trial will consist of a pre-screening consent, a screening period, a run-in period (if applicable), a SAD part with 4 weeks of follow-up after investigational medicinal product (IMP) administration and a washout period of at least 12 weeks (followed by follow-up phone calls until the MAD part starts), a MAD part of 12 weeks, and a MAD extension part of 12 weeks. All subjects will participate in the SAD, MAD, and MAD extension parts, unless they withdraw. End-of-treatment assessments will be performed after 24 weeks of MAD treatment have been completed, i.e. at the Week 25 visit. Subjects will be followed up on adverse events (AEs) and concomitant medications 3 months after the last IMP administration. An interim analysis will be performed when all subjects in cohort 1 and 2 have completed 12 weeks of MAD treatment. The primary analysis will be performed when all subjects in all cohorts have completed 12 weeks of MAD treatment or discontinued earlier. The final analysis will be performed when all subjects have completed 24 weeks of MAD treatment (12 weeks in the MAD part + 12 weeks in the MAD extension part; Week 25 visit) or discontinued earlier. As this trial is investigational, there is no defined, expected benefit for subjects who participate in this trial except a better knowledge of their pathology, and the knowledge that they contribute to RNA-targeted therapy for CNM patients carrying MTM1 and DNM2 mutations.