Yuhan’s IgE inhibitor gets green light in phase 1 trial for chronic urticaria

YH35324, an allergy treatment from Yuhan Corp., has demonstrated high symptom control and superior IgE (immunoglobin E) reduction compared to existing therapies in patients with urticaria, a study said.

According to the study’s abstract, which was released by the American Academy of Allergy, Asthma, and Immunology (AAAAI) on Monday (local time), YH35324, a drug candidate for allergic diseases, showed positive results in a phase 1 clinical trial in patients with chronic spontaneous urticaria (CSU).

YH35324 is an IgE inhibitor acquired by Yuhan in July 2020 from the Korean biotech company GI Innovation. Designed based on IgE Trap-Fc fusion protein, the drug has an action mechanism that effectively inhibits IgE, the main causative agent of allergic diseases.

The study is part 1 of the phase 1 clinical trial (NCT05960708) to evaluate YH35324’s safety, tolerability, pharmacokinetics, and pharmacodynamics (PD)

The researchers randomized 18 patients with chronic spontaneous urticaria refractory to treatment with H1 antihistamines into three groups to receive a single subcutaneous injection of YH35324 3 mg/kg, 6 mg/kg, or 300 mg of omalizumab (Xolair in trademark), a control.

Symptoms were assessed using the weekly Urticaria Activity Score (UAS7) for eight weeks, treatment-emergent adverse events (TEAEs) were monitored, and changes in blood drug concentrations and free IgE levels in serum were analyzed.

The clinical results showed no significant differences in clinical characteristics among the three treatment groups, but YH35324 exhibited a dose-dependent pattern of increased drug exposure as the dose increased. Specifically, free IgE levels within serum in the YH35324 group decreased more significantly than those of omalizumab, with a longer duration of effect.

Furthermore, when comparing the proportion of patients achieving complete control (UAS7=0) and partial control (UAS7≤6) during the eight weeks of treatment, the proportions were 16.7 percent and 50.0 percent in the YH35324 3 mg/kg group and 50.0% and 66.7% in the YH35324 6 mg/kg group, respectively.

This was superior to omalizumab (16.7 percent and 16.7 percent). In addition, the adverse event rate in the YH35324 arm was 27.8 percent, with no serious adverse events reported.

The researchers concluded that YH35324 demonstrated stronger IgE inhibition and symptom control than existing therapies in patients with chronic spontaneous urticaria and proved safe.

The original developer, GI Innovation, believes that YH35324 (also known as GI-301) may be effective in a patient population lacking treatment alternatives, including patients who do not respond to the existing treatment, Xolair.

With positive results from the phase 1 proof-of-concept study, industry insiders are looking to see if further studies will confirm this treatment candidate’s long-term safety and efficacy.

AAAAI and the World Allergy Organization (WAO) will co-host this year’s academic conference from Feb. 28 to March 3 in San Diego, Calif.