Long-Term Extension Study of Imeroprubart in Adult Patients With Graves' Disease

This long-term extension study aims to evaluate the efficacy of imeroprubart in adult patients diagnosed with Graves' disease. The primary objective is to assess the maintenance of euthyroidism following the discontinuation of both antithyroid drugs and the investigational product for a period of 52 weeks in Group A participants. This evaluation is clinically relevant to determine the durability of the therapeutic effect and the potential for sustained remission.

The study population consists of 244 patients diagnosed with Graves' disease. The cohort includes both male and female participants within specific age ranges. Selection for this trial is limited to individuals who have previously completed either Study IMVT-1402-2502 or Study IMVT-1402-2503. The primary objective is to evaluate the efficacy of IMVT-1402 by assessing the maintenance of euthyroidism following the discontinuation of antithyroid drugs and IMVT-1402 for a period of 52 weeks.

This Phase 4 long-term extension study is designed to assess the efficacy, safety, and tolerability of imeroprubart in adult patients diagnosed with Graves' disease. The primary objective is to evaluate the maintenance of euthyroidism in Group A participants following the discontinuation of both antithyroid drugs (ATD) and imeroprubart for a duration of 52 weeks. The study involves the subcutaneous use of a 600 mg solution for injection. Participants must have previously completed either Study IMVT-1402-2502 or Study IMVT-1402-2503 to meet the inclusion criteria. The assessment period extends up to 52 weeks to monitor clinical outcomes, including the percentage of participants remaining euthyroid and the time to confirmed relapse. Secondary endpoints include monitoring thyrotropin receptor antibodies (TRAb) seronegativity and the proportion of participants maintaining clinical stability at 26 weeks and throughout the 52-week period.

The investigational product is imeroprubart, referred to as IMVT-1402. This substance is provided as a solution for injection. The administered dose is 600 mg, delivered via subcutaneous route.

The efficacy of imeroprubart in adult patients with Graves' disease is evaluated through several clinical endpoints. The primary efficacy endpoint is the percentage of Group A participants who maintain euthyroidism, are off antithyroid drugs (ATD), and are off imeroprubart at Week 52.

Secondary efficacy assessments include:

• The percentage of Group A participants who are euthyroid and off ATD at Week 26 and up to Week 52.
• The percentage of Group A participants who are euthyroid, off ATD, and off imeroprubart up to Week 52.
• The time from the earliest date of euthyroidism, off ATD, and off imeroprubart to the earliest date of confirmed relapse in Group A participants up to Week 52.
• The percentage of Group B and Group C participants who remain euthyroid, off ATD, and off imeroprubart at Week 52 and up to Week 52.
• The time from Week 0 to the earliest date of confirmed relapse in Group B and Group C participants up to Week 52.
• The percentage of Group A participants who are euthyroid, off ATD, and seronegative for thyrotropin receptor antibodies (TRAb) at Week 26 and up to Week 52.