AbbVie reported that all three dose regimens of zumilokibart met the primary endpoint in the Phase II APEX Part B study in moderate-to-severe atopic dermatitis, with the mid-dose selected for Phase III development.
Zumilokibart's engineered half-life of approximately 77 days is intended to support maintenance dosing every three to six months, potentially less frequent than approved IL-13 antibodies such as tralokinumab and lebrikizumab, which require dosing every few weeks during maintenance.
APEX Part B was a randomized, double-blind, placebo-controlled study in which 346 participants with moderate-to-severe atopic dermatitis were randomized 1:1:1:1 to low-, mid-, or high-dose zumilokibart or placebo over a 16-week induction period, with the primary endpoint being the proportion achieving EASI-75 at Week 16.
The mid-dose achieved an EASI-75 rate of 65.9% versus 23.4% for placebo (p<0.001); key secondary endpoints also met included IGA 0/1 (46.0% vs. 10.9%), EASI-90 (47.4% vs. 9.3%), and itch improvement (50.5% vs. 13.9%). The mid-dose conjunctivitis rate was 10.6%, compared with 20.7% for the high dose; other common adverse events included nasopharyngitis, headache, and upper respiratory tract infection.