A Phase 2 Study to Evaluate DNTH103 in Adults with Generalized Myasthenia Gravis (MAGIC)

Inclusion Criteria:

1. Must have given written informed consent before any study-related activities arecarried out.

2. Adult males and females, 18 to 75 years of age (inclusive) at Screening.

3. Weight range between 40-120 kg at Screening.

4. Diagnosis of gMG by the following tests: Acetylcholine receptor antibody (AChR Ab) positive, and One of the following: i. History of abnormal neuromuscular transmission test; ii. History of positiveanticholinesterase test; iii. Clinical response to acetylcholinesterase inhibitors.

5. Myasthenia Gravis Foundation of America (MGFA) Class II-Iva

6. Myasthenia Gravis Activities of Daily Living (MG-ADL) score of 6 or more

7. Vaccination against N. meningitidis with the quadrivalent meningococcal vaccine, andwhere available, meningococcal serotype B vaccine within 3 years prior to, or at thetime of, initiating study drug.

8. Female participants must: Be of non-childbearing potential, or if of childbearing potential, must agree not todonate ova, not to attempt to become pregnant and, if engaging in sexual intercoursewith a male partner, must agree to use a highly effective method of contraception.

9. Male participants must be surgically sterile for at least 90 days prior to screeningor agree not to donate sperm

Exclusion Criteria:

1. History or presence of significant medical/surgical condition including any acuteillness or major surgery considered to be clinically significant

2. Prior history (at any time) of N. meningitidis infection.

3. Positive test results for active human immunodeficiency virus (HIV-1 or HIV-2),hepatitis B surface antigen (HBsAg), or hepatitis C virus (HCV) antibodies duringScreening.

4. Any thymic surgery/biopsy within 1 year of Screening.

5. Any known or untreated thymoma.

6. Any history of thymic carcinoma or thymic malignancy.

7. Concurrent or previous use of the following medication within the time periodsspecified below.

8. Rituximab within 6 months (180 days) prior to randomization (Day 1);

9. Intravenous immunoglobulin (IVIg) and plasma exchange (PLEX) within 4 weeks (28days) prior to randomization (Day 1).

10. Participation in another clinical study of an investigational drug within 90 days or 5 half-lives of the investigational agent.