Immunovant experienced a notable premarket share decline of 11.1% after revealing that its two Phase 3 trials testing batoclimab in thyroid eye disease (TED) did not meet the studies' primary endpoint.
The trials, referred to collectively as the GO trials, evaluated batoclimab as an investigational therapy for adults with active, moderate-to-severe TED. According to the company's report, neither study achieved the pre-specified primary outcome under the statistical analysis plan.
The defined primary endpoint was the proptosis responder rate at Week 24 - specifically, the proportion of patients achieving a 2 mm or greater reduction in proptosis after a regimen of 12 weeks of high-dose batoclimab followed by 12 weeks of low-dose treatment. Both studies fell short of that threshold.
Immunovant said the safety profile did not reveal any new safety signals across the two trials.
Despite the headline results, the company pointed to internal data that it described as encouraging. Patients demonstrated larger improvements in proptosis during the initial 12-week high-dose period compared with the subsequent 12-week low-dose phase, a pattern the company says supports the hypothesis that deeper immunoglobulin G - IgG - suppression may be beneficial.
Additionally, among hyperthyroid patients enrolled in the TED studies, rates of thyroid hormone normalization were reported to be broadly consistent with those observed in an earlier Phase 2 batoclimab study in Graves' disease.
Immunovant indicated it will review batoclimab's future development strategy together with its partner HanAll Biopharma and will provide an update at a later date.
The company reiterated its focus on advancing IMVT-1402, an investigational FcRn blocker, across several autoimmune indications. Immunovant identified Graves' disease as a strategic priority for IMVT-1402, and said topline data from potentially registrational IMVT-1402 studies in Graves' disease are expected in 2027.
Context and implications
While neither GO trial met the pre-specified primary endpoint, Immunovant highlighted dose-dependent signals and thyroid hormone findings that mirror prior Phase 2 results. The company plans further review with its development partner and remains committed to advancing a separate FcRn program with upcoming registrational data milestones.