AstraZeneca And Amgen Post Tezspire EoE Phase 3 Win, Opening A Dosing-Based Challenge To Dupixent

AstraZeneca and Amgen said Thursday that Tezspire succeeded in a late-stage study in eosinophilic esophagitis, setting up a possible expansion into a market where Sanofi and Regeneron’s Dupixent is currently the only approved biologic. According to the companies, Tezspire significantly improved histologic remission and dysphagia symptoms at 24 weeks, with the benefit sustained through 52 weeks.

The commercial significance is straightforward: Tezspire is already a growth product for both partners, and eosinophilic esophagitis would add another use inside immunology rather than creating a new franchise from scratch. The strategic question is not whether the result helps Tezspire, but whether it can do enough to dent a much larger incumbent.

The commercial picture

William Blair said Dupixent is the only approved biologic in eosinophilic esophagitis. Dupixent entered the indication in May 2022 after data showed that about 60% of treated patients achieved histologic remission, versus up to 6% on placebo. Dysphagia improved by 21.9 to 23.8 points on a validated questionnaire in treated patients, compared with 9.6 to 13.9 points on placebo.

That is the benchmark Tezspire now has to match or exceed. Truist Securities said Tezspire already has clear differentiation on dosing: an injection every four weeks, versus weekly injections for Dupixent. If efficacy lands in a competitive range, that schedule advantage could matter in physician and patient choice even without a head-to-head study.

Tezspire also arrives with meaningful commercial momentum. The drug generated $1.48 billion in revenue for Amgen in 2025, up 51% year on year. AstraZeneca recorded $1.13 billion in ex-U.S. sales last year, up 64%. William Blair forecast worldwide sales of about $2.7 billion this year and $3.3 billion in 2027. Dupixent remains far larger, growing 26% last year to $17.8 billion globally, according to Regeneron.

What remains unknown

The limitation in Thursday’s update is that AstraZeneca and Amgen did not disclose the specific efficacy figures behind the Phase 3 result. Without those numbers, the market knows Tezspire won, but not the magnitude of the win relative to Dupixent’s established data. The companies said full CROSSING results will be presented at an upcoming scientific conference.

That leaves Tezspire in a familiar but important intermediate position: the readout supports label-expansion potential and adds another growth lever to an already maturing product, yet the size of the opportunity depends on data still to come. For now, the signal is that AstraZeneca and Amgen have moved from theoretical competition with Dupixent in eosinophilic esophagitis to a credible entry bid built around a positive Phase 3 study and a less frequent dosing schedule.