Tezspire Achieves Histologic Remission of Up to 68.9% in Phase III Esophagitis Trial
Key Facts
AstraZeneca and Amgen announced positive results from the Phase III CROSSING trial of Tezspire, known scientifically as tezepelumab, in adolescents and adults with symptomatic, uncontrolled eosinophilic esophagitis. Histologic remission at week 24 was achieved by 64.8% of patients who received a 210 mg dose and 68.9% of those who received 420 mg, compared with 3.5% in the placebo group. AstraZeneca said the difference was statistically significant for both doses. The study also achieved statistically significant improvements in both primary endpoints at week 24: histologic remission and dysphagia symptoms. Complete endoscopic remission after 52 weeks, also cited in the announcement, was a key secondary endpoint.
Histologic remission was sustained through week 52 in 67.8% of patients receiving the 210 mg dose and 63.3% of those receiving 420 mg, compared with 5.4% with placebo. The improvement recorded at week 24 thus extended through the longer follow-up period, with rates remaining clearly higher in both Tezspire groups. On the endoscopic measure, which means the absence of visible signs of the disease, the 210 mg dose produced complete remission in 34.4% of patients, compared with 29.5% with the 420 mg dose. The rate was 4.1% in the placebo group, and the company said the difference on this key secondary endpoint was statistically significant. The results show a difference between the doses on this measure, with the lower dose recording a higher rate than the higher dose.
For dysphagia symptoms at week 24, scores fell by 18.8 points with the 210 mg dose and 22.0 points with the 420 mg dose, compared with a 14.7-point decline with placebo. AstraZeneca reported p=0.049 for the lower dose and p<0.001 for the higher dose. The decline was therefore greater with both doses than with placebo, while the statistical significance was stronger for the higher dose. Doses were administered subcutaneously every 4 weeks. The study defined histologic remission as 6 or fewer eosinophils per high-power field in esophageal tissue, while dysphagia was measured using a questionnaire designed to assess difficulty swallowing.
The CROSSING trial studied the disease in adolescents and adults, allowing participants to continue stable background medications for eosinophilic esophagitis. These included proton pump inhibitors and swallowed topical corticosteroids, meaning the trial results were recorded under a protocol that allowed those treatments to continue. AstraZeneca said the most common side effects among patients receiving Tezspire were upper respiratory tract infections, including nasopharyngitis, headache and diarrhea. It added that the safety profile was consistent with the drug's approved indications. The announcement did not estimate the impact of the results on Tezspire sales or the company's financial outlook.
The company describes eosinophilic esophagitis as a chronic, progressive inflammatory disease and estimates that it affects more than 470,000 people in the United States, with prevalence increasing fivefold since 2009. The initial treatments it cited include dietary restriction, swallowed topical corticosteroids and proton pump inhibitors. AstraZeneca said nearly half of patients, including adolescents, do not achieve adequate disease control with current care options. These figures place the trial in the context of an unmet treatment need, as the company describes it, among a segment of patients. CROSSING results were presented in a late-breaking oral presentation during United European Gastroenterology Week 2026 in Barcelona.
AstraZeneca's executive vice president of research and development said: "We look forward to sharing the CROSSING data with regulatory authorities to make Tezspire available to patients with eosinophilic esophagitis as quickly as possible." Sharing the data is the next step announced by the company, while use of the drug for this disease remains subject to the regulatory review process. According to AstraZeneca's clinical trial registry, study enrollment began on 10 November 2022, and the primary completion date was 14 July 2026. Overall study completion is estimated for 23 March 2027. In trading before the announcement, AstraZeneca shares closed at $172.57 on 22 October 2026.