Disitamab Vedotin

This is a prospective, open label, multicenter clinical study of vediximab combined with PD-1 and radiation therapy for bladder preservation in MIBC patients with HER-2 high expression (IHC 2+or 3+), conducted in accordance with Good Clinical Practice (GCP).
Each patient received treatment with Vediximab injection [2.0 mg/kg, Q2W, iv] and Triprolizumab injection [3mg/kg, Q2W, iv] for one cycle, followed by concurrent radiotherapy in the second cycle. Assuming a 20% improvement in the efficacy of conventional TMT bladder protection treatment, i.e. an increase in CR rate from 60% to 80%, alpha of 0.05, and beta of 0.2, a sample size of 36 is required. Considering a 20% dropout rate, 45 subjects need to be enrolled.
The subjects need to undergo maximum transurethral resection of the bladder (TURBT) and imaging diagnosis, and collect urine samples before treatment. The researchers judged that localized myometrial invasive bladder cancer with high HER2 expression could be treated with bladder conserving therapy by maximizing TURBT. The patient will receive treatment with vediximab combined with PD-1 and radiotherapy after TURBT surgery (without the need for secondary resection).
The subjects should receive treatment with vediximab combined with PD-1 every two weeks for a total of 12 treatment cycles, and receive radiation therapy simultaneously. The specific number of treatment cycles will be determined by the researchers based on the patient's response to the treatment, tolerance to the regimen, and overall judgment of the condition. Patients with safety intolerance caused by any drug treatment will be reduced or discontinued according to the dosage adjustment plan specified in the regimen.
After completing the above treatments, the pathology, imaging, and cytology of the tumor site were obtained through diagnostic TURBT or cystoscopy for tumor evaluation to assess whether complete remission was achieved. The first tumor efficacy evaluation was conducted 3 months after receiving treatment, and the researcher judged whether to continue treatment based on the patient's treatment status. After completing the treatment for the next 3 months, another tumor efficacy evaluation was conducted. After completing all 12 treatment cycles (6 months), the patient underwent two tumor evaluations at the 6th month (from the 12th month of treatment) and the 12th month (from the 24th month of treatment), respectively.

This study aims to evaluate the efficacy of disitamab vedotin combined with toripalimab as a bladder-preserving treatment combination in patients with HER2 positive locally advanced MIBC, including one year bladder-intact DFS (BI-DFS) and safety.