Ivarmacitinib ointment in treatment of adults with mild-to-moderate atopic dermatitis: phase III of a randomized double-blind placebo-controlled phase II/III clinical trial.

Abstract

Effective topical therapies for mild-to-moderate atopic dermatitis (AD) should provide rapid itch relief, sustained anti-inflammatory efficacy and minimal local toxicity. Existing options, including corticosteroids and calcineurin inhibitors, are limited by long-term adverse effects, highlighting the need for safer, steroid-sparing alternatives. To evaluate the efficacy and safety of ivarmacitinib ointment, a highly selective topical Janus kinase 1 inhibitor, applied twice daily in adults with mild-to-moderate AD. This phase III evaluation was part of a multicentre randomized double-blind vehicle-controlled seamless adaptive phase II/III trial conducted at 27 sites in China. Adults aged 18-75 years with Hanifin-Rajka-defined mild-to-moderate AD were randomized (1 : 1 : 1) to ivarmacitinib ointment 0.5%, ivarmacitinib ointment 1% or vehicle for 8 weeks. Patients who initially received the vehicle were re-randomized to active treatment for a blinded extension through week 52. Co-primary endpoints were Investigator's Global Assessment (IGA) response (score 0/1 with ≥ 2-grade improvement) and ≥ 75% improvement in Eczema Area and Severity Index (EASI 75) at week 8. At week 8, significantly more patients achieved an IGA response with ivarmacitinib than with vehicle [ivarmacitinib 0.5%: 21.3% vs. 10.6% (P = 0.02); ivarmacitinib 1%: 26.2% vs. 10.6% (P = 0.001)]. Likewise, EASI 75 responses were higher [ivarmacitinib 0.5%: 42.6% vs. 17.9%; ivarmacitinib 1%: 45.1% vs. 17.9% (both P < 0.001)]. Relief from pruritus was seen within 48 h and maintained through week 52, with sustained improvements in SCORing Atopic Dermatitis (SCORAD), affected body surface area and Dermatology Life Quality Index. During the vehicle-controlled period, treatment-emergent adverse events occurred in 42.6% (n = 52/122), 56.6% (n = 69/122) and 52.0% (n = 64/123) of patients in the ivarmacitinib 0.5%, ivarmacitinib 1% and vehicle groups, respectively; most were mild and infection-related events were infrequent. No treatment-related adverse event occurred in ≥ 2% of patients in the ivarmacitinib 1% or vehicle groups, while in the ivarmacitinib 0.5% group, only folliculitis (n = 5/122; 4.1%) and increased blood uric acid (n = 4/122; 3.3%) were reported in ≥ 2% of patients. No skin atrophy, telangiectasia or application-site irritation was observed. Long-term safety through week 52 remained consistent, with no new safety signals noted. Twice-daily ivarmacitinib ointment (0.5% or 1%) produced rapid, durable and well-tolerated improvements in the signs, symptoms and itch experienced by adults with mild-to-moderate AD, supporting its potential as a safe, steroid-sparing topical therapy.