Japanese healthcare company Daiichi Sankyo Co Ltd (TYO:4568) announced on Wednesday that the first patient has been dosed in the phase 3 TROPION-Urothelial04 trial evaluating Datroway (datopotamab deruxtecan) as an adjuvant treatment for patients with high-risk muscle-invasive urothelial cancer (MIUC) following radical surgery.

The trial will assess Datroway plus rilvegostomig or Datroway monotherapy versus current standard-of-care treatments, including durvalumab, nivolumab or enfortumab vedotin plus pembrolizumab.

Datroway is a TROP2-directed DXd antibody-drug conjugate discovered by Daiichi Sankyo and jointly developed and commercialised with British-Swedish biopharmaceutical company AstraZeneca plc (STO:AZN) (LON:AZN) (NYSE:AZN). Rilvegostomig is AstraZeneca's anti-PD-1/TIGIT dual checkpoint inhibitor bispecific antibody.

MIUC accounts for approximately 30% of urothelial cancer cases and carries a substantial risk of recurrence after surgery. Adjuvant immunotherapy remains the standard of care, but additional treatment options are needed to improve long-term outcomes, Daiichi Sankyo said. No TROP2-directed medicines are currently approved for urothelial cancer.

Daiichi Sankyo and AstraZeneca are also evaluating Datroway with platinum-based chemotherapy in the phase 2/3 TROPION-Urothelial03 trial for patients with metastatic urothelial carcinoma who progressed during or after enfortumab vedotin plus pembrolizumab.