Tezepelumab-ekko (Tezspire) met both co-primary endpoints in the Phase 3 CROSSING trial for eosinophilic esophagitis, a disease affecting 470,000 Americans, AstraZeneca and Amgen said Thursday.
"These results reinforce our confidence in the differentiated mechanism of action of Tezspire, which has now demonstrated clinically meaningful efficacy in a third epithelial-driven inflammatory disease," Sharon Barr, executive vice president of BioPharmaceuticals R&D at AstraZeneca, said.
The CROSSING trial randomized 368 patients aged 12-80 with symptomatic and histologically active EoE to receive a low or high dose of Tezspire or placebo subcutaneously every four weeks. The co-primary endpoints at week 24 were histologic remission, defined as a peak esophageal eosinophil count of six or fewer per high-power field, and mean changes from baseline in the Dysphagia Symptom Questionnaire. Both doses showed statistically significant and clinically meaningful improvements compared with placebo, sustained through week 52. The safety profile was generally consistent with the drug's approved indications.
Tezspire generated $1.13 billion in sales for AstraZeneca in 2025. The drug is already approved for severe asthma and chronic rhinosinusitis with nasal polyps in the US, EU, China and Japan. EoE prevalence has grown five-fold since 2009, and nearly half of patients do not respond to standard first-line therapies such as proton pump inhibitors or swallowed topical corticosteroids.
Tezspire is a first-in-class human monoclonal antibody that blocks thymic stromal lymphopoietin, a key epithelial cytokine that triggers inflammation in conditions driven by eosinophils, a type of white blood cell. The drug competes with Sanofi and Regeneron's Dupixent in severe asthma.
The positive readout offers a boost for AstraZeneca after a string of pipeline setbacks. In July, Wainua unexpectedly failed a heart disease trial, while a late-stage study of rare disease drug Ultomiris also failed. In May, a US regulatory panel rejected its breast cancer drug camizestrant on trial design grounds. AstraZeneca also halted an advanced study of experimental lung cancer drug volrustomig this month.
Jay Bradner, executive vice president of research and development at Amgen, said the results "build confidence in Tezspire as a potential new treatment for people struggling with EoE."
AstraZeneca shares were down 0.5 percent in London trading Thursday, having fallen 14 percent since Wainua's trial failure. Amgen closed down 0.4 percent in New York on Wednesday.
Full results will be shared with regulatory authorities and the scientific community at an upcoming medical meeting. The companies did not disclose a regulatory submission timeline.
The positive data de-risks Tezspire's pipeline value and opens a new revenue stream in a growing EoE treatment market, where existing options fail nearly half of patients. Investors will watch for regulatory submissions and upcoming results from two AstraZeneca cancer trials seen as critical to the company's $80 billion sales target by 2030.
This article is for informational purposes only and does not constitute investment advice.