Study of NM8074 in Patients with Dermatomyositis (DM)

Inclusion Criteria: * Male and female patients ≥18 years of age at the time of consent. * A body mass index (BMI) within the range of 15 - 38 kg/m2. BMI = Body weight (kg) / \[Height (m)\]2. * Subjects diagnosed with a probable or definite DM according to 2017 European League Against Rheumatism/American College of Rheumatology (2017 EULAR/ACR). * Subjects must have proof of vaccination against Neisseria meningitidis (MenACWY and MenB), Streptococcus pneumoniae (PCV13 or PCV15 and PPSV23), and Haemophilus influenzae type b (Hib) taken at least 2 weeks prior to NM8074 administration as per national and local guidelines. If the window of vaccination is short, then patients will be prophylactically treated with appropriate antibiotics. * Female partners of child-bearing potential (WOCBP), defined as all women physiologically capable of becoming pregnant, must have a negative pregnancy test at screening and must agree to use highly effective methods of contraception during dosing and for at least 8 weeks after stopping the investigational drug. * Male patients and partners of child-bearing potential must agree to use contraceptives, and male patients must agree to refrain from donating sperm for the duration of the study and for at least 8 weeks after stopping the investigational drug. Exclusion Criteria: * Subjects with drug-induced myositis * Subjects who have interstitial lung disease requiring the use of supplemental oxygen. * Use of other investigational drugs at the time …