Tezspire Hits Phase 3 CROSSING Endpoints in Eosinophilic Esophagitis, Teeing Up a Third Indication

Amgen (Nasdaq: AMGN) and AstraZeneca announced positive top-line results from the Phase 3 CROSSING trial of Tezspire (tezepelumab-ekko) in eosinophilic esophagitis (EoE), with the TSLP antibody hitting both co-primary endpoints at Week 24 and carrying the benefit through Week 52. The readout tees up a third epithelial-driven indication for a drug already approved in severe asthma and chronic rhinosinusitis with nasal polyps.

The trial met its two co-primary endpoints. Tezspire produced a statistically significant and clinically meaningful gain in histologic remission, defined as a peak esophageal eosinophil count of six or fewer per high-power field, and a meaningful improvement in dysphagia measured on the Dysphagia Symptom Questionnaire. Both benefits held through Week 52. The study randomized 368 patients 1:1:1 to a low or high dose of Tezspire or placebo.

EoE is a chronic inflammatory disorder of the esophagus that affects more than 470,000 people in the U.S., with prevalence up five-fold since 2009. The inflammation narrows the esophagus and makes swallowing difficult, raising the risk of food impaction. Nearly half of patients, including adolescents, do not get adequate control from the standard first-line options of dietary elimination, swallowed topical corticosteroids, and proton pump inhibitors.

The mechanism is the point. Tezspire blocks thymic stromal lymphopoietin (TSLP), an epithelial cytokine that sits at the top of multiple inflammatory cascades. That upstream position is why the same antibody keeps showing activity across what Amgen calls epithelial-driven diseases. Tezspire won its first approval in severe asthma in 2021 and added CRSwNP last year. EoE would be the third, and Amgen is also running the drug in COPD across the COURSE, JOURNEY, and EMBARK trials.

The commercial setup is a co-development with AstraZeneca. The two split global costs and profits evenly, AstraZeneca leads development, and Amgen books U.S. sales. For Amgen, that makes Tezspire a rare large-cap growth driver, and EoE extends the runway beyond the crowded asthma market.

The competition is real. Dupixent (dupilumab) is already approved for EoE and anchors Sanofi’s immunology franchise, so Tezspire would enter as a second biologic, differentiated by its every-four-weeks dosing and its TSLP-first mechanism rather than Dupixent’s IL-4/IL-13 blockade.

Amgen shares barely budged, trading around $440, flat from Wednesday’s $440.34 close. The readout was largely expected after the WAYPOINT CRSwNP data proved the drug’s epithelial-driven thesis. What to watch next: the full Week 52 dataset at a medical meeting, and whether Amgen and AstraZeneca file for the EoE label, which would make Tezspire a three-indication franchise.

Source: Amgen press release, August 27, 2026