This is an open-label phase 2/3 study for individuals with Congenital Myotonic Dystrophy (Congenital DM1) who participated in the preceding AMO-02-MD-2-003 study or individuals with either Congenital or Childhood Onset DM1 who are treatment naïve.
Subjects under study must be individuals with a diagnosis of Congenital or Childhood Onset DM1.
Diagnosis must be genetically confirmed
Subjects must be male or female aged ≥6 years to ≤45 years at Screening
Subjects must have a Clinical Global Impression - Severity (CGI-S) score of 3 or greater at Screening (V-1)
Body mass index (BMI) less than 13.5 kg/m² or greater than 40 kg/m²
New or change in medications/therapies within 4 weeks prior to Eligibility/Baseline Visit
Use within 4 weeks prior to Eligibility/Baseline Visit of strong CYP3A4 inhibitors (eg.clarithromycin, telithromycin, ketoconazole, itraconazole, posaconazole, nefazodone, idinavir and ritonavir)
Concurrent use of drugs metabolized by CYP3A4 with a narrow therapeutic window (e.g. warfarin and digitoxin)