Forte Biosciences (FBRX) investor relations material

Disease background and market opportunity

• Vitiligo is an autoimmune skin disease affecting 0.76% of the population, with significant physical and emotional impacts and a substantial unmet need for safe, effective therapies.

• Existing treatments like JAK inhibitors face regulatory scrutiny, leaving room for new therapies.

Mechanism of action and preclinical rationale

• FB102 blocks IL-2 and IL-15 via CD122, targeting both CD8+ and CD4+ T cell pathways implicated in vitiligo, while preserving regulatory T cells.

• Preclinical mouse models showed anti-CD122 antibodies can restore pigmentation and provide durable responses with infrequent dosing.

Study design and methodology

• Double-blind, placebo-controlled phase I-B study in vitiligo enrolled 43 subjects, randomized 3:1 (32 on FB102, 11 on placebo), with two dosing cohorts and a 12-week treatment period followed by 12 weeks off therapy, efficacy evaluated at week 24.

• Primary endpoint was mean percent F-VASI improvement at week 24, assessed by central review by an independent expert.

• Efficacy evaluable population excluded one placebo subject due to protocol criteria, providing a conservative assessment.