This is a long-term extension study that will rollover participants completing feeder studies IMVT-1402-2502 (NCT06727604) or IMVT-1402-2503 (NCT07018323) to evaluate the efficacy and safety of IMVT-1402 in adult participants with GD. Eligible participants will be assigned to 1 of 3 study groups (Groups A, B and C) based on their GD status at the completion of their respective feeder study.

Inclusion Criteria:

• Participants who completed Study IMVT-1402-2502 or Study IMVT-1402-2503.
• Other, more specific inclusion criteria are defined in the protocol.

Exclusion Criteria:

• Have permanently discontinued IMP during the treatment period in the feeder study or have met study stopping criteria at any point up until the end of participation in the feeder study.