Zumilokibart Shows Rapid Symptom Relief in Atopic Dermatitis

Key Takeaways

• Zumilokibart demonstrated rapid improvements in itch, sleep, and skin pain, with effects observed as early as 48 hours.
• Sustained and clinically meaningful benefits across symptoms and quality of life were maintained through Week 16.
• Extended dosing intervals, enabled by a prolonged half-life, support less frequent administration with durable efficacy.

Zumilokibart (APG777), a half-life–extended anti–IL-13 monoclonal antibody, demonstrated rapid and sustained improvements in symptoms and quality of life in patients with moderate-to-severe atopic dermatitis (AD), according to Phase 2 APEX Part A results presented by Emma Guttman-Yassky, MD, PhD, at the American Academy of Dermatology (AAD) 2026 Annual Meeting.

The randomized study enrolled 123 adults assigned 2:1 to zumilokibart or placebo, with a 16-week induction phase involving only four dosing days. Dr. Guttman-Yassky highlighted the pharmacokinetic profile as a key differentiator, noting that the therapy’s extended half-life of approximately 77 days allows for dosing of 12 weeks and 24 weeks, with potential implications for long-term treatment burden. 

Clinical improvements were observed early.

“Itch already was significantly improved by two days—by 48 hours—sleep by week 1, and skin pain was significantly improved already by week 2,” Dr. Guttman-Yassky said.

These findings were reflected in patient-reported outcomes, with significant reductions in itch, nighttime awakenings, and skin pain compared with placebo as early as Weeks 1–2, and sustained through Week 16.

At Week 16, two-thirds of patients receiving zumilokibart achieved EASI-75, consistent with previously reported efficacy. Patient-reported quality of life also improved significantly, with 76.3% achieving a ≥4-point reduction in Dermatology Life Quality Index (DLQI) compared with 40.5% in the placebo group (P < .001).

Dr. Guttman-Yassky emphasized both speed and durability of response, noting that improvements “were increasingly significant and more meaningful towards week 16.” Longer-term data suggested continued benefit, with increasing response rates observed during maintenance dosing intervals of every 12 or 24 weeks.

The treatment was well tolerated, with adverse events consistent with IL-13 pathway inhibition, including noninfective conjunctivitis and upper respiratory tract infection.

“These results support continued evaluation of the drug and dose optimization,” Dr. Guttman-Yassky said.