Kymera’s KT-621 Achieves ≥98% STAT6 Degradation in Japanese Phase 1 Trial
KYMR•Kymera Therapeutics reported that oral Phase 1 dosing of KT-621 in 24 healthy Japanese adults achieved dose-proportional exposure and ≥98% STAT6 degradation. It was well tolerated with a favorable safety profile, and parallel Phase 2b atopic dermatitis and asthma trials will read out by mid-2027 and late 2027.
1. Phase 1 Study Design and Outcomes
The randomized, double-blind, placebo-controlled Phase 1 trial enrolled 24 healthy Japanese adults across two dose levels randomized 3:1 to receive once-daily KT-621 or placebo for seven days. KT-621 demonstrated rapid absorption, dose-proportional plasma exposure and median STAT6 degradation of ≥98% at both dose levels by Day 7.
2. Safety and Tolerability
KT-621 was well tolerated with no serious adverse events reported and a favorable safety profile across both dose cohorts. Reported side effects were mild and transient, aligning with prior data from non-Japanese healthy volunteers and atopic dermatitis patients.
3. Ongoing Phase 2b Trials and Timeline
Kymera has initiated parallel Phase 2b trials of KT-621 in atopic dermatitis (BROADEN2) and asthma (BREADTH), with interim data expected by mid-2027 for dermatitis and late 2027 for asthma. These studies aim to inform dose selection for subsequent global Phase 3 registration trials in multiple Type 2 inflammatory diseases.
