Immunovant has announced positive results from its Phase IIa trial of batoclimab in patients with Graves' disease who remain hyperthyroid despite antithyroid drug (ATD) therapy. The trial data showed a significant reduction in immunoglobulin G (IgG) levels and strong clinical response rates, suggesting a potential new treatment option for this patient population. Immunovant also plans to initiate a pivotal trial for IMVT-1402 in Graves' disease by the end of 2024.
Batoclimab Phase IIa Trial Results
The Phase IIa trial (NCT05907668) enrolled Graves' disease patients with hypothyroidism despite ongoing ATD treatment. Participants received 680 mg of batoclimab weekly via subcutaneous injection for 12 weeks, followed by 340 mg weekly for an additional 12 weeks. The primary endpoint was the percentage of participants who achieve normalization of T3 and T4 hormone levels or have them below the lower limit of normal (LLN) after 24 weeks.
After the initial 12 weeks of high-dose batoclimab (680mg), patients experienced a mean IgG reduction of 77%. This led to a 76% response rate, defined as triiodothyronine (T3) and thyroxine (T4) levels falling below the upper limit of normal (ULN) without increasing the ATD dose. Furthermore, 56% of patients achieved an ATD-Free Response, meaning their T3 and T4 levels fell below the ULN, and they were able to completely taper off their ATD medication.
However, during weeks 13 to 24, the lower 340mg dose of batoclimab resulted in a mean IgG reduction of 65%, with a correspondingly lower responder rate of 68% and an ATD-Free Response rate of 36%.
According to Immunovant, patients who achieved at least a 70% IgG reduction at the end of the trial had nearly a threefold higher ATD-Free Response rate than those who did not (60% vs. 23%).
IMVT-1402 Pivotal Trial
Immunovant has also received FDA clearance for its Investigational New Drug (IND) application for IMVT-1402. The company plans to initiate a pivotal trial of IMVT-1402 in Graves' disease by the end of the year. The trial design has been aligned with the FDA.
Market Opportunity
Immunovant estimates that 25-30% of Graves' disease patients per year are uncontrolled on ATDs, representing a significant commercial opportunity with limited competition. Pete Salzmann, M.D., chief executive officer of Immunovant, stated, "We find the correlation between clinical response and IgG lowering impressive and believe this creates not only a potential first-in-class but also a potential best-in-class opportunity for IMVT-1402."
Current Treatment Landscape for Graves' Disease
Graves’ disease is an autoimmune condition characterized by an overactive thyroid gland, leading to elevated levels of thyroid hormones (T3 and T4). Current treatment options primarily involve antithyroid drugs (ATDs) to manage hyperthyroidism. However, a significant portion of patients remain uncontrolled on ATDs, highlighting the need for alternative therapeutic strategies.
Batoclimab is also being evaluated by Immunovant in thyroid eye disease and chronic inflammatory demyelinating polyneuropathy (CIDP).
