AstraZeneca and Daiichi Sankyo have announced promising Phase 3 trial results for Datroway, their investigational antibody-drug conjugate (ADC) targeting triple-negative breast cancer (TNBC). The trial demonstrated that Datroway significantly slowed tumor progression and extended overall survival compared to standard chemotherapy in patients with metastatic or locally recurrent, inoperable TNBC who are ineligible for immunotherapy.

This marks the first time a survival advantage has been observed over chemotherapy in this patient population, with the companies describing the results as “statistically significant and clinically meaningful.” Datroway targets the TROP2 protein, which is overexpressed in several cancers, and builds on the success of Enhertu, another ADC from the same collaboration.

The full trial data will be presented at an upcoming medical conference, and submissions to global health authorities are planned. Following the announcement, AstraZeneca’s stock rose over 1%, while Daiichi Sankyo’s climbed approximately 4%.

Datroway may reshape the treatment landscape for TNBC, though it faces competition from Gilead’s Trodelvy, another TROP2-targeting ADC. AstraZeneca estimates that around 70% of TNBC patients are not eligible for immunotherapy, underscoring the urgent need for more effective alternatives.