Inclusion Criteria

• Male and female 
• 18 to 65 years of age
• Women of child-bearing potential must be willing to use highly effective methods of contraception during study treatment and for 12 weeks after the last study treatment
• Grave's hyperthyroidism diagnosed within approximately the last 6 months prior to screening
• Patients must weigh at least 40 kg to participate in the study

Exclusion Criteria

• History of treatment of Graves' disease with radio-iodine ablation or thyroidectomy and/or current treatment with anti-thyroid drugs (methimazole or propylthiouracil) within 3 months of starting the study treatment
• History of hyperthyroidism not caused by Graves' disease (e.g. toxic multinodular goiter, autonomous thyroid nodule, or acute inflammatory thyroiditis) and/or history or presence of thyroid storm (fever, profuse sweating, vomiting, diarrhea, delirium, severe weakness, seizures, markedly irregular heartbeat, yellow skin and eyes (jaundice), severe low blood pressure, and coma)
• Previous treatment with a B cell-depleting biologic agent or any other immune-modulatory biologic agent within 5 half-lives (experimental or approved)
• History of recurrent clinically significant infection or of recurrent bacterial infections with encapsulated organisms
• History of primary or secondary immunodeficiency, including a positive HIV (ELISA and Western blot) test result
• History or evidence of tuberculosis by either of the following tests
  • Positive PPD skin test (size of induration measured after 48-72 hours, and a positive result is defined as an induration of ≥ 5mm or according to local practice/guidelines) OR
  • Positive QuantiFERON TB-Gold test
• Plans for immunization with a live vaccine within a 2-month period before enrollment or during the study period
• Treatment with immunomodulatory drugs, such as cyclosporine A, methotrexate, and/or cyclophosphamide within 3 months from baseline
  • Glucocorticosteroid therapy with prednisolone up to 10 mg daily is permitted if patients are on stable dose for more than 3 months before enrollment in the study
• Pregnant or breastfeeding females
• Women of child bearing potential who will not use highly effective contraception