Amgen and AstraZeneca’s Tezspire has delivered a significant phase 3 clinical win in eosinophilic esophagitis, intensifying competition with Sanofi and Regeneron’s Dupixent.
The companies announced that the phase 3 CROSSING trial hit all primary and key secondary endpoints, marking a major milestone for the anti-TSLP biologic.
Tezspire demonstrated statistically significant improvements in both histologic remission and swallowing difficulties compared to placebo at week 24 of the trial.
Treatment effects on both co-primary endpoints were sustained through week 52 across both doses of Tezspire that were tested in the trial.
The success positions Tezspire to potentially expand into its third inflammatory disease indication, beyond severe asthma and chronic rhinosinusitis with nasal polyps.
Eosinophilic esophagitis is a chronic inflammatory disease of the esophagus that can cause narrowing and difficulty swallowing, known as dysphagia, affecting more than 470,000 people in the US.
Tezspire targets and blocks thymic stromal lymphopoietin, a key epithelial cytokine sitting at the top of multiple inflammatory cascades that drives an overreactive immune response.
This upstream mechanism of action differs from Dupixent, which works downstream in the immune cascade by blocking IL-4 and IL-13 signalling pathways.
Dupixent became the first medicine specifically indicated for EoE in 2022, with pivotal data showing around 60% of treated patients achieved histologic remission compared to up to 6% on placebo.
The CROSSING trial was a randomised, double-blind, placebo-controlled, multi-centre phase 3 study evaluating Tezspire administered subcutaneously every four weeks in patients aged 12 to 80 years.
Primary investigator Arjan Bredenoord, MD, gastroenterologist and professor at the Amsterdam University Medical Center, highlighted the strength of the results across the full year of follow-up.
“The impressive results from the CROSSING trial sustained over 52 weeks demonstrate that tezepelumab, taken every four weeks, could provide a new approach to treating this disease, with the potential to help more patients achieve remission and symptom improvement,” Bredenoord said.
The safety profile observed in the trial was described as generally consistent with Tezspire’s profile in its already approved indications, offering some reassurance ahead of a potential regulatory submission.
Dupixent currently holds nine approved immunological indications, making it one of the most broadly approved biologics in the inflammatory disease space and a formidable commercial rival.
Amgen and AstraZeneca will now look to leverage the CROSSING data to pursue regulatory approval, opening what would be a significant new commercial front against the established Dupixent franchise.