Chinese biopharmaceutical company RemeGen Co Ltd (SH:688331) (HK:9995) announced on Monday that its phase 3 clinical trial of disitamab vedotin (DV) combined with the PD-1 inhibitor toripalimab for first-line treatment of HER2-expressing locally advanced or metastatic urothelial carcinoma met its primary endpoints of progression-free survival (PFS) and overall survival (OS).

The trial's positive interim results were validated by the Independent Data Monitoring Committee (IDMC), demonstrating statistically significant differences and clinically meaningful benefits. PFS and OS improved across major subgroups, regardless of cisplatin eligibility or HER2 expression levels, and the combination treatment exhibited a manageable safety profile.

The phase 3 trial, RC48-C016, began in June 2022, involving 484 patients across 74 sites in China. It compared DV plus toripalimab to gemcitabine combined with cisplatin/carboplatin in systemic-treatment-naive patients.

RemeGen plans to present detailed results at upcoming international academic conferences later this year and intends to submit a Biologic License Application to the Center of Drug Evaluation of China's National Medical Products Administration.

Disitamab vedotin is the first domestically approved antibody-drug conjugate in China. The success of this trial represents a major milestone in advancing treatment options for patients with advanced urothelial carcinoma.