Comparing Disitamab Vedotin Plus Gemcitabine or Toripalimab Before Surgery in Adults with HER2-Positive Muscle-Invasive Bladder Cancer

What this Trial Is About

Researchers are evaluating two different neoadjuvant treatment strategies for adults with muscle-invasive bladder cancer MIBC that expresses the HER2 protein. The study aims to compare disitamab vedotin RC48 combined with gemcitabine versus disitamab vedotin combined with toripalimab before surgery, focusing on the rate of complete tumor removal confirmed by pathology. This is a Phase 3 trial designed to assess if the two treatment approaches are similarly effective in this setting. Participants will be randomly assigned to one of two groups one receives disitamab vedotin plus gemcitabine, and the other receives disitamab vedotin plus toripalimab. Both treatments are given intravenously every two weeks for 3 to 6 cycles, depending on tumor response seen in imaging after the initial 3 cycles. After completing neoadjuvant therapy, all patients undergo radical cystectomy with pelvic lymph node dissection within four weeks. Those eligible will then receive additional adjuvant therapy with disitamab vedotin plus toripalimab for 6 cycles, followed by up to one year of toripalimab maintenance therapy. During the study, participants will have regular imaging scans of the abdomen, pelvis, and chest every 3 to 6 months after surgery, or cystoscopy and imaging if bladder-sparing treatment is chosen. Study staff will contact participants every 3 months to track imaging results and symptoms such as hematuria or respiratory issues, and to document any cancer recurrence or progression. The primary outcome is the pathological complete response rate measured shortly after surgery. Safety is monitored through tracking treatment-related adverse events during neoadjuvant therapy. The total study duration is up to 3 years from start to completion.

Neoadjuvant RC48 Plus Gemcitabine in HER2-Expressing MIBC