Cue Biopharma, Inc. announced positive topline results from a Phase 2 clinical trial of its investigational drug candidate CUE-221 in patients with Chronic Spontaneous Urticaria (CSU). The trial, conducted in China by Genesis Life Sciences, an affiliate of Ascendant Health Ltd., enrolled 145 participants with moderate to severe CSU whose symptoms were inadequately controlled despite H1-antihistamine treatment.

The study was a multicenter, randomized, double-blind, placebo and active comparator-controlled trial. Patients were randomized to receive subcutaneous injections of CUE-221 at doses of 4 mg/kg, 2 mg/kg, or 1 mg/kg every four weeks (Q4W), or placebo Q4W, or the active comparator omalizumab (XOLAIR) 300 mg Q4W. The primary endpoint was the proportion of patients achieving HSS7=0 (a score indicating complete resolution of hives) at week 12.

The data indicated that the primary endpoint was met at all dose levels of CUE-221. Specifically, 54% of patients in the 4 mg/kg group achieved HSS7=0 at week 12, compared to 53% in the 2 mg/kg group, 43% in the 1 mg/kg group, and 11% in the placebo group. The key secondary endpoint, measuring complete response (UAS7=0) at week 12, was met at the highest dose level of 4 mg/kg, with 46% of patients achieving this result versus 39% at 2 mg/kg, 38% at 1 mg/kg, and 11% in the placebo group.

Further analysis showed that the percentage of patients achieving HSS7=0 peaked at Week 22 across all CUE-221 dose groups. Benefit was maintained for up to 12 weeks after the last dose was administered at the 4 mg/kg dose level, with 60% of patients achieving HSS7=0 at Week 28. Post hoc analysis at Week 28 demonstrated a statistically significant difference versus omalizumab.

Cue Biopharma reported that CUE-221 demonstrated a favorable safety profile during the trial. There were no treatment-related serious adverse events and no cases of hypersensitivity reactions, including anaphylaxis. Injection site reactions were infrequent, with only one case exceeding grade 1 severity.

Based on these results, the company stated it plans to initiate a Phase 2b/3 trial in CSU and a Phase 2 trial in food allergy. The company will host a conference call and webcast on September 21, 2026, at 8:00 a.m. E.T. to discuss the clinical data.