Disitamab Vedotin Alone or in Combination With Immune Checkpoint Inhibitors in Bladder-Sparing Treatment of Muscle-Invasive Bladder Cancer: A Real-World Study.

ABSTRACT

PURPOSE: To evaluate the efficacy and safety of a novel humanized anti-HER2 antibody, RC48-ADC (Disitamab vedotin, DV), the combination of RC48-ADC with PD-1 inhibitors was used to treat muscle-invasive bladder cancer (MIBC). This combination therapy has potential applications in both bladder preservation and neoadjuvant therapy for MIBC. METHODS: Patients with MIBC underwent transurethral resection of bladder tumors followed by RC48-ADC alone or in combination with PD-1 inhibitors. Radiological and endoscopic evaluations were conducted 3 months later. The primary endpoint was objective response rate (ORR), with secondary endpoints including complete response rate (CR), partial response rate (PR), and bladder preservation rate. Treatment safety was assessed according to RECIST v1.1 criteria. RESULTS: Eleven patients were enrolled, with a median follow-up of 19.0 months. Nine patients achieved objective response, including 6 CR and 3 PR cases. The pathological ORR was 81.8%. Eight patients continued combined treatment after 3 months, maintaining a 72.7% bladder preservation rate at 16 months. One elderly patient progressed from ypT2N0M0 to ypT3N0M0 and underwent radical cystectomy but had no recurrence or metastasis 12 months postoperation. All patients reported varying degrees of treatment-related adverse reactions, which were largely manageable. CONCLUSION: The combination of RC48-ADC and PD-1 inhibitors proves to be a viable and safe option for bladder-sparing therapy, particularly for T2-stage MIBC patients who are ineligible for surgery and chemotherapy. This approach offers a promising new direction for bladder preservation or neoadjuvant therapy in MIBC patients.