Kymera’s KT-579 Matches JAK Inhibitors, Completely Blocks TNFα and IL-6 in IBD Model
Kymera’s investigational IRF5 degrader KT-579 achieved disease activity score reductions and complete inhibition of TNFα, IL-1β and IL-6 in TNBS-induced IBD models, matching or surpassing JAK inhibitors and integrin/TNF biologics. A Phase 1 healthy volunteer trial evaluating safety and IRF5 degradation is ongoing with data due 2H26.
1. Preclinical IBD Efficacy
KT-579 showed dose-dependent reduction in disease activity score and prevention of body weight loss in a TNBS-induced IBD model, demonstrating activity comparable or superior to a JAK inhibitor as well as integrin- and TNF-targeting biologics.
2. Mechanism of Action and Cytokine Inhibition
Selective degradation of IRF5 by KT-579 led to complete inhibition of key inflammatory cytokines TNFα, IL-1β and IL-6 in colon tissue, normalization of myeloid and fibrosis-associated gene expression, and preservation of crypt structure without abscess formation.
3. Phase 1 Healthy Volunteer Trial
The ongoing Phase 1 study is evaluating single- and multiple-ascending oral doses of KT-579 versus placebo to assess safety, tolerability, pharmacokinetics, pharmacodynamics and functional IRF5 degradation, with topline results expected in the second half of 2026.