This report is based on public company disclosures, filings and announcements reviewed by GSN; figures are as stated by the company and have not been independently verified.

Cue Biopharma (Nasdaq: CUE) said on September 20, 2026 that a Phase 2 trial of its anti-IgE antibody CUE-221 in chronic spontaneous urticaria met its primary endpoint at all three dose levels tested. The trial, run in China by Genesis Life Sciences, a related company of Cue’s licensor Ascendant Health Limited, enrolled 145 participants with moderate to severe hives that remained inadequately controlled on H1 antihistamines, according to the release.

Patients were randomized 2:2:2:1:1 to CUE-221 at 4 mg/kg, 2 mg/kg or 1 mg/kg every four weeks, to placebo, or to omalizumab 300 mg every four weeks, for a 16-week treatment period followed by 20 weeks of follow-up. The primary endpoint was the share of patients with a weekly hives severity score of zero (HSS7=0) at week 12. The company reported 54 percent at 4 mg/kg, 53 percent at 2 mg/kg and 43 percent at 1 mg/kg, against 11 percent on placebo and 41 percent on omalizumab. The key secondary endpoint, a weekly urticaria activity score of zero (UAS7=0) at week 12, was met at the 4 mg/kg dose, at 46 percent against 11 percent on placebo.

The company said there were no treatment-related serious adverse events and no cases of anaphylaxis, and that it is “working toward the rapid initiation” of a Phase 2b/3 study in the disease and a planned Phase 2 study in food allergy. It said it would present the complete data set, including pharmacokinetic and IgE analyses, at “an upcoming scientific meeting”.

Reading the release

The trial was designed to show superiority over placebo, and on the reported figures it did. The comparison with omalizumab, the approved standard sold as Xolair, is a different matter, and the release says so in its design paragraph: omalizumab was included “to enable comparative efficacy without planned statistical testing”. At week 12, the omalizumab arm’s confidence interval, 18 to 67 percent, overlaps every CUE-221 arm’s interval, including 37 to 71 percent at the top dose. The one statistical comparison with omalizumab the release does report, a 36 percentage point difference at week 28, is labelled post hoc, meaning it was chosen after the data were in. The quoted opinion of Dr Dale Umetsu that CUE-221 “was better than XOLAIR for CSU at all dose levels tested” is prefaced by the words “appear to”; it is a clinician’s reading, not a tested result.

The arms are small, and the tables do not account for everyone. The reported group sizes are 35, 36, 37, 18 and 17, which sum to 143 against the 145 participants the release says were enrolled; the release does not say how the analysis population was defined or what happened to the other two. On an 18-patient placebo arm, 11 percent is two patients, so the placebo rate that anchors every comparison rests on two people.

The release reports safety in a narrow frame. Saying there were “no treatment-related serious adverse events” leaves open whether there were serious adverse events judged unrelated, and no adverse event rates by arm are given. The dosing is also asymmetric: CUE-221 was dosed by body weight and omalizumab at a fixed 300 mg, and the release gives no weight data, so total drug exposure cannot be compared. Data beyond week 28 of the 36-week study are not reported.

The release does not establish the independence of two people it quotes. Dr Tse-Wen Chang is described as the innovator of UB-221. Dr Umetsu is described as the prior global lead for Xolair development; the release does not say whether he advises or is paid by Cue. The trial itself was conducted by Genesis, which holds rights in China, Hong Kong, Macau and Taiwan, not by Cue, and the forward-looking statements name as a risk “potential challenges associated with clinical trials conducted in China”. The same section refers to the company’s “limited cash and a history of losses”. The release gives no cash figure, no cost or size for the Phase 2b/3 study and no date for its start beyond “rapid”.

Questions worth asking

Who were the two enrolled patients missing from the tables, and how was the analysis population defined? The arm sizes sum to 143, not 145, and the release does not explain the difference.

Will the US regulator accept a China-only Phase 2 as the basis for a Phase 2b/3 design? The release lists trials conducted in China as a risk, and it does not say whether Cue has met the agency about the next study.

Were there any serious adverse events at all, related or not? The release reports only that none were treatment-related, and gives no adverse event rates by arm.

How much will the Phase 2b/3 cost, and how will it be funded? The release names limited cash as a risk and gives no budget, enrollment target or start date.

Key terms in this story

Active comparator. An approved drug given to one arm of a trial so that the new drug’s effect can be seen alongside it. Here that drug was omalizumab, and the release states the trial was not designed to test the new drug against it statistically.

Post hoc analysis. A comparison chosen after the results are known rather than written into the protocol beforehand. The one statistical comparison with omalizumab in this release, at the end of the off-treatment period, is labelled this way.

Hives severity score. A patient-recorded weekly measure of hive severity; a score of zero means no hives for the week. It was the primary endpoint, measured twelve weeks into treatment, and the urticaria activity score adds itch to the same tally.

Confidence interval. The range within which the true response rate is likely to sit given the number of patients studied. The intervals in this release are wide because the arms are small, and the omalizumab interval overlaps the intervals for every dose of the new drug.

What to watch

September 21, 2026 at 8:00 a.m. EDT: the company’s conference call and webcast on the results.

The company said it will present the complete data set, including PK and IgE analyses, at an upcoming scientific meeting; no date or meeting was given.

The company said it is working toward initiation of a Phase 2b/3 study in chronic spontaneous urticaria and continues to advance a planned Phase 2 study in food allergy; no dates were given.

Sources