New horizons for autoimmune hyperthyroidism with FcRn blockers
Fearghas Middleton, Prakash AbrahamPurpose of review
Advances in understanding of autoimmune hyperthyroidism and neonatal Fc receptor (FcRn) biology have created an opportunity for a novel immunomodulatory treatment approach. This review is timely in evaluating newly emerged literature for FcRn blockers Batoclimab (IMVT-1401), Imeroprubart (IMVT-1402) and Efgartigimod (ARGX-113) in Graves’ disease and thyroid eye disease.
Recent findings
Preliminary phase 2 clinical trial data of Batoclimab therapy in Graves’ disease demonstrated rapid normalisation of thyroid hormone levels with the majority maintaining this after the treatment course. Rapid declines in anti-TSH receptor antibodies were observed with a subset of patients achieving sustained seroconversion. A case report described maintained remission of Graves’ disease 23 months following short-course Batoclimab therapy. Batoclimab was well tolerated with no treatment-related adverse events. Phase 3 clinical trials of Efgartigimod therapy in thyroid eye disease were terminated early due to it unlikely achieving the intended clinical efficacy following interim analysis. Mid- and late-phase clinical trials for Imeroprubart and Batoclimab therapy in Graves’ disease and thyroid eye disease are ongoing.
Summary
FcRn blockade is a promising new therapeutic approach for the management of autoimmune hyperthyroidism. Durability, cost-effectiveness and patient selection remain to be defined.