Forte Biosciences, Inc.

Forte Biosciences, Inc. is a clinical-stage biopharmaceutical company focused on developing therapeutic candidates for autoimmune and autoimmune-related conditions. Its primary product candidate is FB102, a proprietary anti-CD122 monoclonal antibody. FB102 targets key pathways involved in these conditions by acting as a CD122 antagonist. CD122 is a component of IL-2/IL-15 receptors, which regulate NK cells and certain T cell subsets. In laboratory studies, FB102 significantly inhibited the proliferation of T cells (4-5x inhibition) and NK cells (6-8 fold inhibition) stimulated with IL2 or IL15, and also inhibited T cell activation. The level of inhibition was comparable to unstimulated cells. Regulatory T cell proliferation was similar with or without FB102. In these in-vitro assays, FB102 showed superiority over competing antibodies. In non-human primate studies, a single dose of FB102 led to significant reductions in the NK cell pharmacodynamic marker (up to approximately 80%-90%). Multiple doses at human therapeutic exposures resulted in Treg levels similar to the control group. A Phase 1 trial in healthy volunteers, involving three single-dose cohorts and two multiple-dose cohorts, was completed, demonstrating a good safety profile with no dose-limiting toxicities. FB102 showed significant reductions in the NK cell pharmacodynamic marker (greater than approximately 70%). Following this, the company initiated a patient-based Phase 1b trial for celiac disease in the third quarter of 2024 and another for non-segmental vitiligo in the first quarter of 2025.