Cue Biopharma, Inc. filed a Form 8-K with the SEC on September 21, 2026, disclosing positive topline results from a Phase 2 clinical trial of CUE-221 in Chronic Spontaneous Urticaria conducted in China by Genesis Life Sciences, an affiliate of Ascendant Health Ltd.

Key Highlights

  • Trial enrollment: The Phase 2 study enrolled 145 participants with moderate to severe CSU whose disease remained inadequately controlled despite treatment with H1-antihistamines.
  • Primary endpoint met: The proportion of patients achieving HSS7=0 at week 12 was dose-responsive and met at all dose levels: 54% (4 mg/kg), 53% (2 mg/kg), and 43% (1 mg/kg), versus 11% for placebo.
  • Key secondary endpoint: The proportion of patients achieving UAS7=0 at week 12 reached statistical significance at the 4 mg/kg dose level (46%, p<0.05) versus 11% for placebo.
  • Durable response: At week 28, 12 weeks after the last dose, 60% of patients in the 4 mg/kg group achieved HSS7=0, compared to 24% for omalizumab, with a statistically significant post hoc delta of 36%.
  • Safety profile: According to the filing, there were no treatment-related serious adverse events and no cases of hypersensitivity reactions including anaphylaxis.
  • Regulatory plans: The company disclosed it recently submitted an IND to the FDA for food allergy and intends, subject to FDA review, to initiate a Phase 2 trial in food allergy and a Phase 2b/3 trial in CSU.

CUE-221 Phase 2 CSU Trial Design and Results in Detail

According to the filing, the Phase 2 study was a multicenter, randomized, double-blind, placebo and active comparator-controlled trial conducted in China. Patients were randomized in a 2:2:2:1:1 ratio across five groups receiving subcutaneous CUE-221 at 4 mg/kg, 2 mg/kg, or 1 mg/kg every four weeks (Q4W), placebo Q4W, or omalizumab 300 mg Q4W. The study included a 16-week treatment period followed by a 20-week post-treatment follow-up. The primary endpoint was the proportion of patients achieving HSS7=0 at week 12, and the study was designed to test superiority over placebo. Omalizumab was included to enable comparative efficacy without planned statistical testing.

The filing reported that the primary endpoint was met at all three CUE-221 dose levels. At the 4 mg/kg dose (N=35), 54% of patients achieved complete resolution of hives (HSS7=0) at week 12, with a 95% confidence interval of 37% to 71% and p<0.005 versus placebo. The 2 mg/kg group (N=36) achieved 53% (95% CI: 36%, 70%; p<0.005), and the 1 mg/kg group (N=37) achieved 43% (95% CI: 27%, 61%; p<0.05). The placebo group (N=18) showed 11% response. The company disclosed that the response rates further increased beyond week 12, peaking at week 22 across all CUE-221 dose groups, with the 4 mg/kg group reaching 69%.

On safety, the filing stated that CUE-221 "demonstrated a favorable safety profile," with no treatment-related serious adverse events, no anaphylaxis or hypersensitivity reactions, and only one injection site reaction above grade 1, with none leading to study discontinuation. The filing noted that all forward-looking statements, including plans for additional clinical trials, are subject to the company's cautionary language under the Private Securities Litigation Reform Act of 1995. The company is listed on the Nasdaq Capital Market under the ticker NASDAQ:CUE.

What Was Disclosed

Cue Biopharma disclosed topline Phase 2 results for CUE-221 in Chronic Spontaneous Urticaria, reporting that the primary and a key secondary endpoint were met, that a durable response was observed 12 weeks post-treatment, and that the company plans further clinical development in CSU and food allergy.