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 LeagueAgainst Rheumatism/American College of Rheumatology (2017 EULAR/ACR).

• Subjects must have proof of vaccination against Neisseria meningitidis (MenACWY andMenB), Streptococcus pneumoniae (PCV13 or PCV15 and PPSV23), and Haemophilusinfluenzae type b (Hib) taken at least 2 weeks prior to NM8074 administration as pernational and local guidelines. If the window of vaccination is short, then patientswill be prophylactically treated with appropriate antibiotics.

• Female partners of child-bearing potential (WOCBP), defined as all womenphysiologically capable of becoming pregnant, must have a negative pregnancy test atscreening and must agree to use highly effective methods of contraception duringdosing and for at least 8 weeks after stopping the investigational drug.

• Male patients and partners of child-bearing potential must agree to usecontraceptives, and male patients must agree to refrain from donating sperm for theduration of the study and for at least 8 weeks after stopping the investigationaldrug.

Exclusion Criteria:

• Subjects with drug-induced myositis

• Subjects who have interstitial lung disease requiring the use of supplementaloxygen.

• Use of other investigational drugs at the time of enrollment, or within 5 half-lives of enrollment or within 3 months to study day 1, whichever is longer.

• History of currently active or suspicion of active bacterial, viral, or fungalinfection within 2 weeks prior to first dose, or history of unexplained, recurrentbacterial infections.

• Subjects currently or previously diagnosed with cancer or who finished their cancertreatment within 2 years of the start of the clinical trial.

• Subjects with the history of bone marrow, hematopoietic stem cells, or solid organtransplantation.

• Has a currently active or known history of meningococcal disease or N. meningitidisinfection.

• Evidence of active malignant disease or malignancies diagnosed within the previous 5year

• Clinically significant medical or psychological conditions or risk factors that, asper the Investigator's judgment, could hinder the patient's participation in thestudy, introduce additional risks for the patient, or complicate the evaluation ofthe patient or study outcomes.

• Pregnant, planning to become pregnant, or nursing female subjects.

• Females with a positive pregnancy test result at Screening or on Day 1.