WILMINGTON, DE — AstraZeneca and Amgen reported that their immunotherapy TEZSPIRE significantly reduced esophageal inflammation and swallowing difficulties in a Phase III clinical trial, strengthening the companies’ case for expanding the drug into the treatment of eosinophilic esophagitis, a chronic inflammatory disease that can make eating difficult.
Full results from the CROSSING trial showed that TEZSPIRE, also known as tezepelumab, achieved its two primary treatment objectives after 24 weeks in adolescents and adults whose disease remained uncontrolled despite existing medications.
The improvements persisted through 52 weeks, according to findings presented at United European Gastroenterology Week 2026 in Barcelona, Spain.
At week 24, 64.8% of patients receiving 210 milligrams of TEZSPIRE and 68.9% receiving 420 milligrams achieved histologic remission, compared with 3.5% of patients given a placebo. Both differences were statistically significant.
Histologic remission indicates that inflammation has fallen below a specified threshold when tissue samples are examined under a microscope.
The treatment also improved swallowing symptoms, a central measure of disease burden in eosinophilic esophagitis, or EoE.
Patients receiving the 210-milligram dose experienced an average 18.8-point reduction from baseline on the Dysphagia Symptom Questionnaire, while those receiving 420 milligrams recorded a 22-point reduction. The placebo group improved by 14.7 points.
The difference between the lower dose and placebo narrowly met the conventional threshold for statistical significance, with a p-value of 0.049. The higher dose produced a stronger statistical result, with a p-value below 0.001.
By week 52, histologic remission rates remained elevated at 67.8% for the lower dose and 63.3% for the higher dose, compared with 5.4% for placebo.
Swallowing symptom scores also continued to improve, declining by an average of 22.1 points and 24 points, respectively, compared with 13.2 points in the placebo group.
The study additionally measured changes visible during endoscopic examinations of the esophagus.
At week 52, 34.4% of patients receiving 210 milligrams and 29.5% receiving 420 milligrams achieved total endoscopic remission, compared with 4.1% of placebo recipients.
That outcome indicates the absence of visible disease features, including inflammation-related changes and fibrosis, during endoscopic examination.
The findings provide evidence across three measures of EoE treatment response: tissue inflammation, patient-reported swallowing symptoms and visible abnormalities in the esophagus.
EoE occurs when immune-related inflammation damages the esophagus, potentially causing difficulty swallowing, food becoming lodged and narrowing of the esophageal passage.
Current treatments include dietary restrictions, proton pump inhibitors and swallowed topical corticosteroids. Nearly half of patients, including adolescents, do not achieve adequate disease control with existing approaches, according to the companies.
Participants in CROSSING were permitted to continue stable background treatment with proton pump inhibitors or swallowed topical corticosteroids.
“The CROSSING trial results are compelling because they show consistent, lasting improvements across three key measures of eosinophilic esophagitis,” said Arjan Bredenoord, a gastroenterologist at Amsterdam University Medical Center and the trial’s international coordinating investigator.
He emphasized that the improvements occurred even among patients who continued taking their existing medications.
TEZSPIRE was administered by subcutaneous injection every four weeks.
The drug blocks thymic stromal lymphopoietin, or TSLP, a protein involved in initiating inflammatory responses. By inhibiting that pathway, TEZSPIRE is designed to reduce inflammation associated with several immune-mediated diseases.
The treatment’s safety profile in CROSSING was consistent with its established use in other conditions, according to AstraZeneca and Amgen.
The most frequently reported adverse events were nasopharyngitis, headache and diarrhea.
TEZSPIRE is already approved for severe asthma in the United States, European Union, China, Japan and more than 70 countries. It is also approved for chronic rhinosinusitis with nasal polyps in the United States, European Union, China and Japan.
The companies are pursuing additional indications, including chronic obstructive pulmonary disease, through the ongoing Phase III JOURNEY and EMBARK trials.
Sharon Barr, AstraZeneca’s executive vice president of biopharmaceuticals research and development, said the company plans to present the CROSSING findings to regulatory authorities as it seeks to expand TEZSPIRE’s use to patients with EoE.
The positive Phase III results support that potential expansion, although TEZSPIRE has not yet received regulatory approval for eosinophilic esophagitis.
For AstraZeneca and Amgen, the findings add another potential commercial application for a medicine already marketed across multiple respiratory and inflammatory conditions.
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