With little time elapsed since AstraZeneca and Amgen unveiled a topline win for Tezspire over the summer, the partners are upping the stakes with a detailed look at their inflammation-fighting antibody’s prowess in eosinophilic esophagitis (EoE).
With the win fleshed out, AZ and Amgen are now eyeing regulatory filings to carve out a potential third indication for Tezspire, in what would also mark the first major challenge to Sanofi and Regeneron’s Dupixent in EoE following its 2022 FDA nod as the first drug specifically approved for the condition.
Headlining the detailed readout—presented at 2026’s United European Gastroenterology Week in Barcelona—were the 64.8% and 68.9% histologic remission rates, as defined by a low count of peak eosinophils in the esophagus, achieved by patients on 210- and 420-mg doses of Tezspire, respectively, at the 24-week mark of the phase 3 Crossing trial. That compared to a slim 3.5% among those who got a placebo, Amgen and AZ said in an Oct. 20 release.
Tezspire also helped cut the frequency and severity of patients’ symptoms of dysphagia, or the difficulty swallowing that is a hallmark of EoE and a frequent source of stress and discomfort for people living with the condition. By the numbers, the drug was tied to a 22-point reduction in dysphagia symptom frequency and severity at the higher dose versus 14.7 points on placebo, as measured on the patient-reported Dysphagia Symptom Questionnaire.
Of particular note, the Tezspire results were maintained in patients through a full year, as borne about by a series of key secondary endpoints.
The Crossing results signal a “big achievement” for Amgen and AZ, said Caterina Brindicci, AZ’s SVP and global head of R&D, respiratory, heralding Tezspire as the first biologic drug to chart statistically significant improvements across multiple EoE measures—namely underlying inflammation, difficulty swallowing and visible signs of disease in the esophagus.
“We see histologic remission, we see decreased frequency and severity of the dysphagia system—which is really key in this population—and we see endoscopic remission,” Amgen’s VP of global development for inflammation, Alison Church, said in an interview.
Brindicci pointed to the duration of the response seen on Tezspire as “particularly significant” in a chronic, progressive disease like EoE, wherein many patients continue to face a substantial burden of disease despite use of other treatments.
On the Crossing study’s secondary objectives, Amgen and AZ tied Tezspire to statistically significant improvements in endoscopic features and severity—as assessed on the EoE Endoscopic Reference Score—at weeks 24 and 52. By the end of one year of treatment, nearly 30% of patients on the higher Tezspire dose achieved total endoscopic remission, defined as having no visible features of EoE.
EoE is a chronic and progressive inflammatory disorder, epithelial in nature, that affects the esophagus, with common symptoms including difficulty and pain when swallowing, food becoming stuck in the esophagus, potentially requiring medical intervention, and nausea and vomiting. Concerns about choking can also take a psychological toll on patients, AZ and Amgen pointed out in Tuesday’s announcement.
While there are a handful of treatment options used to address EoE in the first line, these are not purpose-built and have a middling track record of success, with Regeneron and Sanofi’s Dupixent becoming the first medicine specifically indicated for the disease back in 2022.
Unlike Dupixent, which works downstream in the immune cascade by blocking IL-4 and IL-13 signaling pathways, Tezspire targets thymic stromal lymphopoietin (TSLP) upstream of the process.
Amgen and AZ have had success with the approach in respiratory conditions using Tezspire, which won an initial green light in severe asthma in late 2021 and for chronic rhinosinusitis with nasal polyps last October.
Now, the Crossing results further validate the partners’ TSLP inhibition thesis in immune-mediated diseases, showing that Tezspire is capable of “targeting TSLP protein at the source before the inflammation builds and the disease progresses,” Brindicci said.
Even with a relatively new biologic option in Dupixent, more treatments are needed to tackle EoE, which Amgen and AZ estimate affects more than 470,000 people in the U.S. That prevalence has been increasing in recent years, further complicated by delays in time to diagnosis, Brindicci pointed out.
“Despite the availability of first-in-line therapy—so, dietary interventions,” Brindicci said, “many patients continue to experience the burden of the disease, including difficulty swallowing, as well as substantial impact on their quality of life.”
Elaborating on those day-to-day struggles for people with the condition, Amgen’s Church noted that some 50% of patients who start on standard EoE treatments—including diet restrictions, topical steroids and protein pump inhibitors—continue to experience symptoms.
“They’re still struggling to swallow,” she said. “They’re drinking lots of water whenever they take a bite of food, trying to get it down. They’re experience kind of that fear of choking, despite being on medicines for this disease.”
With the phase 3 data in hand, Amgen and AZ now look forward to discussing the results with regulators, with the partners “really looking forward to bringing this option as quickly as possible to patients,” Brindicci explained.