Kymera Therapeutics (KYMR) Study Result summary

Immunology strategy and rationale for STAT6 targeting

• STAT6 is a key transcription factor downstream of IL-4/IL-13, validated by human genetics and clinical data, making it an ideal target for Th2 diseases.

• Oral STAT6 degraders like KT-621 aim to replicate biologics-like efficacy with the convenience of oral dosing, addressing unmet needs in large patient populations underserved by injectable biologics.

• Targeted protein degradation enables continuous pathway blockade, overcoming limitations of traditional small molecules and matching or exceeding biologic efficacy.

• The immunology market is large and underserved, with only 3% of patients on advanced systemic therapies; oral options could address significant unmet need.

• The program aims to disrupt conventional treatment paradigms and expand access to advanced therapies for millions of patients.

Study design and objectives

• Phase 1 trial was randomized, double-blind, placebo-controlled, enrolling 118 healthy volunteers in single and multiple ascending dose cohorts.

• Primary objectives included assessment of safety, tolerability, pharmacokinetics, STAT6 degradation in blood and skin, and Th2 biomarker modulation.

• Exploratory endpoints included STAT6 protein levels in blood and skin, and Th2 biomarker changes.

Key efficacy and pharmacodynamic results

• KT-621 achieved rapid, robust, and dose-proportional STAT6 degradation in blood and skin, with >90% mean degradation at all doses above 1.5 mg and complete degradation at ≥50 mg.

• Maximal STAT6 degradation in blood observed as early as 4 hours post-dose; steady-state complete degradation at doses ≥50 mg.

• Steady-state was reached by day 4 of daily dosing, and recovery of STAT6 began within days after dosing stopped.

• KT-621 reduced Th2 biomarkers: median TARC reduction up to 37% and Eotaxin-3 reduction up to 63% at Day 14, comparable or superior to dupilumab.

• IgE changes were minimal and consistent with effects seen in dupilumab healthy volunteer studies.