Study to Determine if BHV-1300 is Effective and Safe in Adults With Graves' Disease

Key Inclusion Criteria:

• Participants must have serologically confirmed Graves' disease as documented by presence of elevated autoantibodies
• Participants must have active hyperthyroidism due to Graves' disease

Key Exclusion Criteria:

• History of hyperthyroidism not caused by Graves' Disease (e.g., toxic adenoma or toxic multinodular goiter)
• History of treatment with radioactive iodine or thyroid surgery.
• Have received levothyroxine, desiccated thyroid extract, or T3 at any dose within six weeks of the Baseline/Day 1 Visit.
• Thyroid storm, i.e. severe thyrotoxicosis with evidence of systemic decompensation (e.g., Burch-Wartkofsky Point Scale of ≥ 45 or Japanese Thyroid Association category 1 or 2, with accompanying manifestations including hyperpyrexia, tachycardia, arrhythmias, congestive heart failure, agitation, delirium, psychosis, stupor, and coma, as well as nausea, vomiting, diarrhea, or hepatic failure) within 6 weeks of Screening.
• Have autoimmune disease other than Graves' disease requiring treatment
• Have moderate to severe thyroid eye disease (TED) and are expected to require immediate surgical intervention and/or are planning corrective surgery/irradiation or medical therapy for TED during study participation.
• Are expected to require urgent or emergent thyroid surgery or ablation within six weeks of Baseline/Day 1 or throughout the study.