Amgen and AstraZeneca presented summary detailed data over the weekend from the Phase 3 CROSSING trial of Tezspire in eosinophilic esophagitis, an allergic inflammatory disease of the esophagus that makes swallowing difficult. Nearly 70 percent of patients on the highest dose were in histologic remission at 24 weeks, against 3.5 percent of patients on placebo.
The topline result is not new: the companies announced in August that CROSSING, which randomized 368 patients to a low dose, a high dose or placebo given subcutaneously every four weeks, met both co-primary endpoints, histologic remission and improvement in dysphagia measured by questionnaire, with benefits maintained through week 52. What the weekend data add is the size of the remission gap, which is the number clinicians will compare, cautiously, against other therapies.
The obvious comparison is Dupixent, from Sanofi and Regeneron, the only other biologic approved for the disease. Cross-trial comparisons are unreliable because populations and endpoints differ, but the remission figure presented for Tezspire sits higher than what was observed in Dupixent testing, and a William Blair analyst called the results best in disease and a route to another blockbuster indication for the drug. More detailed findings are due at a medical meeting on Wednesday, October 14.
Tezspire, a TSLP blocker sold for severe asthma, is a shared asset: Amgen and AstraZeneca split its economics, so an esophagitis indication expands a franchise both companies already count on. The companies say more than 470,000 people in the United States live with eosinophilic esophagitis. A filing timeline has not been set out in the weekend reporting, and that, plus the full safety table, is what the Wednesday presentation needs to supply.