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

Prior treatment

• Prior history (at any time) of N. meningitidis infection.
• Any thymic surgery/biopsy within 1 year of Screening.
• Concurrent or previous use of the following medication within the time periods specified below.
  • Rituximab within 6 months (180 days) prior to randomization (Day 1);
  • Intravenous immunoglobulin (IVIg) and plasma exchange (PLEX) within 4 weeks (28 days) prior to randomization (Day 1).
• Participation in another clinical study of an investigational drug within 90 days or 5 half-lives of the investigational agent.

Other illness

• History or presence of significant medical/surgical condition including any acute illness or major surgery considered to be clinically significant
• Positive test results for active human immunodeficiency virus (HIV-1 or HIV-2), hepatitis B surface antigen (HBsAg), or hepatitis C virus (HCV) antibodies during Screening.
• Any history of thymic carcinoma or thymic malignancy.

Other

• Any known or untreated thymoma.

• Must have given written informed consent before any study-related activities are carried out.
• Adult males and females, 18 to 75 years of age (inclusive) at Screening.
• Weight range between 40-120 kg at Screening.
• Diagnosis of gMG by the following tests:
  • Acetylcholine receptor antibody (AChR Ab) positive, and
  • One of the following:
  • History of abnormal neuromuscular transmission test; ii. History of positive anticholinesterase test; iii. Clinical response to acetylcholinesterase inhibitors.
• Myasthenia Gravis Foundation of America (MGFA) Class II-Iva
• Myasthenia Gravis Activities of Daily Living (MG-ADL) score of 6 or more
• Vaccination against N. meningitidis with the quadrivalent meningococcal vaccine, and where available, meningococcal serotype B vaccine within 3 years prior to, or at the time of, initiating study drug.
• Female participants must:
  • Be of non-childbearing potential, or if of childbearing potential, must agree not to donate ova, not to attempt to become pregnant and, if engaging in sexual intercourse with a male partner, must agree to use a highly effective method of contraception.
• Male participants must be surgically sterile for at least 90 days prior to screening or agree not to donate sperm