ADS-019 for Myotonic dystrophy type 1

Inclusion criteria

• {"criterion_text":"-Males and females who are ≥18 to ≤65 years of age at the time of informed consent."}
• {"criterion_text":"-A genetically confirmed diagnosis of DM1 with DMPK CTG repeat length ≥100 based on Screening evaluation or source verifiable medical records."}
• {"criterion_text":"-Have clinician-assessed signs of DM1 including clinically apparent myotonia equivalent to hand opening time of at least 2 seconds (in the opinion of the Investigator)."}
• {"criterion_text":"-Had the onset of clinically significant DM1 symptoms after the age of 12 years."}
• {"criterion_text":"-Can walk for at least 10 meters independently at Screening (orthoses allowed; canes and walkers are not allowed)."}
• {"criterion_text":"-Subjects of childbearing potential must agree to use highly effective contraception in addition to a condom during the study and for at least 90 days following the end of the study or last dose of study drug, whichever is later. Subjects must not donate sperm or eggs during the study and for at least 90 days following the end of the study or last dose of study drug, whichever is later."}

Exclusion criteria

• {"criterion_text":"-Body mass index ≥40 kg/m2."}
• {"criterion_text":"-Seropositive for hepatitis B (positive hepatitis B virus surface antigen at Screening) or hepatitis C (HCV) at Screening, (positive for anti-HCV antibody must be confirmed with positive HCV-RNA test for exclusion)."}
• {"criterion_text":"-Active infection that, in the opinion of the PI, would interfere with the subject’s ability safely tolerate and/or complete the study."}
• {"criterion_text":"-History of malignancy within the last 2 years except for adequately treated basal cell carcinoma, squamous cell skin cancer, superficial bladder tumors, or in situ cervical cancer. Subjects with other curatively treated malignancies who have no evidence of metastatic disease and >2-year disease-free interval may be entered following approval by the Medical Monitor."}
• {"criterion_text":"-Recent history of or current drug and/or alcohol abuse (at the discretion of the site PI)."}
• {"criterion_text":"-Presence of risk for increased or uncontrolled bleeding and/or risk of bleeding that is not managed optimally and could place a subject at an increased risk for intraoperative or postoperative bleeding. These could include, anticipated need, in the opinion of the Investigator, for administration of any antiplatelet or anticoagulant around each biopsy procedure, and underlying disorders of the coagulation cascade, platelet function, or platelet count (eg, hemophilia, Von Willebrand’s disease, liver disease)."}
• {"criterion_text":"-History of poorly controlled thyroid dysfunction per discretion of the PI."}
• {"criterion_text":"-Untreated or poorly controlled epilepsy."}
• {"criterion_text":"-Uncontrolled hypertension."}
• {"criterion_text":"-History of TA biopsy within 3 months of Day 1 or planning to undergo tibialis anterior (TA) biopsies (outside of this study) during the study period."}
• {"criterion_text":"-Recent treatment with an investigational drug within 30 days or 5 half-lives (whichever is longer) prior to first dose or current participation in an investigational study."}
• {"criterion_text":"-Treatment with anti-myotonia medication (or medications that can improve myotonia) within a period of 5 half-lives of the medication prior to performing screening assessment. Subjects must not use anti-myotonia medication for the duration of the study."}
• {"criterion_text":"-Current concomitant use of theophylline (including duration of study)."}
• {"criterion_text":"-Clinically significant cardiac, liver, or renal disease (please refer to the protocol for details)."}
• {"criterion_text":"-HIV infection, as shown by the presence of anti-HIV antibody (seropositive) at Screening."}
• {"criterion_text":"-History of inadequately controlled diabetes."}
• {"criterion_text":"-Any contraindications to muscle biopsy."}
• {"criterion_text":"-Any condition that, in the opinion of the Investigator, would make the subject unsuitable for inclusion, or could interfere with the subject’s ability to participate in or completing the study."}
• {"criterion_text":"-Confirmed diagnosis of congenital DM1."}
• {"criterion_text":"-Screening values of coagulation parameters including platelet count, INR, prothrombin time, and activated partial thromboplastin time (APTT) should be within normal ranges. Subjects with non-clinically significant and stable out-of-range values may be eligible to enroll in the study at the discretion of the Investigator."}
• {"criterion_text":"-Intellectual disability or significant behavioral neuropsychiatric manifestation."}
• {"criterion_text":"-A history of torsade de pointes, ventricular rhythm disturbances (eg, ventricular tachycardia or fibrillation), heart block (excluding first-degree block, being PR interval prolongation only), congenital long QT syndrome, corrected QTc value >450 ms in males and >470 ms in females, new ST segment elevation or depression, or new Q wave on ECG. Subjects with a history of atrial arrhythmias should be discussed with the Medical Monitor. Symptomatic heart failure (per New York Heart Association guidelines), unstable angina, myocardial infarction, severe cardiovascular disease (ejection fraction <20%), transient ischemic attack, or cerebrovascular accident within 24 weeks prior to first dose."}

Primary endpoints

• {"endpoint_text":"-Incidence, frequency, and severity of treatment-emergent adverse events (TEAEs) and treatment-related AEs in subjects with DM1 over time through the end of study (EOS)","definition_or_measurement_approach":"Measured as incidence, frequency and severity of treatment-emergent adverse events (TEAEs) and treatment-related adverse events over time through end of study (EOS)."}

Secondary endpoints

• {"endpoint_text":"-Plasma PK of ARO-DM1 in subjects with DM1.","definition_or_measurement_approach":"Plasma pharmacokinetics of ARO-DM1 (measurement of plasma PK parameters/time profile); specific PK sampling and parameters not specified in the CTIS JSON."}

Methods

• Dr-Dr referral letters (documents: Dr-Dr Referral Letter) — country-specific versions present for Germany, Spain, Belgium, Italy.
• Patient brochures (documents: Patient brochure) — country-specific versions present for Germany, Spain, Belgium, Italy.
• Patient posters (documents: PatientPoster / Patient poster) — country-specific versions present for Germany, Spain, Belgium, Italy.
• Social media posts (documents: SocialMediaPost / Social Media Post) — country-specific versions present for Germany, Spain, Belgium, Italy.
• K1 Recruitment arrangements (administrative recruitment material) — country-specific K1 documents present for Germany, Spain, Belgium, Italy.

Germany

Earliest CTIS Part Ii Submission Date

12-01-2026

Latest Decision Or Authorization Date

29-01-2026

Processing Time Days

17

Number Of Sites

2

Number Of Participants

5

Spain

Earliest CTIS Part Ii Submission Date

13-01-2026

Latest Decision Or Authorization Date

03-02-2026

Processing Time Days

21

Number Of Sites

4

Number Of Participants

20

Belgium

Earliest CTIS Part Ii Submission Date

11-12-2025

Latest Decision Or Authorization Date

30-01-2026

Processing Time Days

50

Number Of Sites

2

Number Of Participants

13

Italy

Earliest CTIS Part Ii Submission Date

11-12-2025

Latest Decision Or Authorization Date

30-01-2026

Processing Time Days

50

Number Of Sites

4

Number Of Participants

20

Primary sponsor

Full Name

Arrowhead Pharmaceuticals Inc.

Organisation Type

Pharmaceutical company

Country Of Registered Address

United States

Contract research organisations

Name

Novotech (Australia) Pty Limited

Responsibilities

Full Service CRO

Name

Novotech Clinical Research (Cyprus) Limited

Responsibilities

Sponsor duties codes: 1;12;5 (specific role descriptions not provided in CTIS JSON)

Name

Medpace Imaging Core Lab

Responsibilities

Central reader for ECG

Third parties

• {"country":"Ireland","full_name":"Rxsource Limited","duties_or_roles":"14","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Keystone Bioanalytical Inc.","duties_or_roles":"4","organisation_type":"Pharmaceutical company"}
• {"country":"Canada","full_name":"Charles River Laboratories Montreal ULC","duties_or_roles":"4","organisation_type":"Pharmaceutical company"}
• {"country":"Portugal","full_name":"CGC Centro De Genetica Clinica E Patalogia S.A.","duties_or_roles":"4","organisation_type":"Hospital/Clinic/Other health care facility"}
• {"country":"United States","full_name":"Arrowhead Pharmaceuticals Inc.","duties_or_roles":"4","organisation_type":"Pharmaceutical company"}
• {"country":"Germany","full_name":"Meditrade GmbH","duties_or_roles":"Supplying equipment and supplies to sites","organisation_type":"Pharmaceutical company"}
• {"country":"Australia","full_name":"Novotech (Australia) Pty Limited","duties_or_roles":"Full Service CRO","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Medpace Imaging Core Lab","duties_or_roles":"Central reader for ECG","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"Netherlands","full_name":"Emsere B.V.","duties_or_roles":"Supplying equipment and supplies to sites","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Suvoda LLC","duties_or_roles":"3","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United Kingdom","full_name":"Chillibean Limited","duties_or_roles":"Supplying vHOT (iPad) equipment to sites","organisation_type":"Pharmaceutical company"}
• {"country":"Belgium","full_name":"MEDPACE LABORATORIES","duties_or_roles":"4","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United Kingdom","full_name":"ATOM International Limited","duties_or_roles":"4","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United States","full_name":"Curia Bio California Inc.","duties_or_roles":"14","organisation_type":"Pharmaceutical company"}
• {"country":"Cyprus","full_name":"Novotech Clinical Research (Cyprus) Limited","duties_or_roles":"1;12;5","organisation_type":"Pharmaceutical company"}
• {"country":"United States","full_name":"Arrowhead Pharmaceuticals Inc.","duties_or_roles":"8","organisation_type":"Pharmaceutical company"}