Immunovant/IMVT-1402-2502 This study is testing IMVT-1402 vs Placebo in patients with Graves disease.

Inclusion:

• 18-75 years old
• Diagnosed Graves Disease
• TSH <0.1
• TRAB ≥4.5
• On anti-thyroid drug for ≥ 3 months if treated with ≥20mg/day methimazole or equivalent

OR

• On anti-thyroid drug for ≥6 months of ≥10mg methimazole or equivalent

The study includes the following periods:

• Screening Period: up to 5 weeks
• Period 1 (blinded treatment): 26 weeks
• Period 2 (blinded treatment): 26 week
• Period 3 (off treatment observation): 52 week
• Safety Follow-up Period: approximately 4 weeks

The total duration of study participation is expected to be up to 109 weeks for an individual participant.