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. 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. 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. 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.

中文翻译：

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Disitamab Vedotin 单独使用或与免疫检查点抑制剂联合使用保留膀胱治疗肌肉浸润性膀胱癌：一项真实世界研究

为了评估新型人源化抗 HER2 抗体 RC48-ADC（Disitamab vedotin，DV）的有效性和安全性，将 RC48-ADC 与 PD-1 抑制剂联合用于治疗肌层浸润性膀胱癌（MIBC）。这种联合疗法在 MIBC 的膀胱保留和新辅助治疗中都有潜在的应用。 MIBC 患者接受经尿道膀胱肿瘤切除术，然后单独使用 RC48-ADC 或联合 PD-1 抑制剂。 3个月后进行放射学和内窥镜评估。主要终点是客观缓解率（ORR），次要终点包括完全缓解率（CR）、部分缓解率（PR）和膀胱保留率。根据 RECIST v1.1 标准评估治疗安全性。 11 名患者入组，中位随访时间为 19.0 个月。 9例患者获得客观缓解，其中CR 6例，PR 3例。病理ORR为81.8%。 8名患者3个月后继续联合治疗，16个月时膀胱保留率保持在72.7%。一名老年患者从ypT2N0M0进展为ypT3N0M0并接受根治性膀胱切除术，但术后12个月未出现复发或转移。所有患者都报告了不同程度的治疗相关不良反应，这些不良反应基本上是可以控制的。 RC48-ADC 和 PD-1 抑制剂的组合被证明是膀胱保留治疗的可行且安全的选择，特别是对于不适合手术和化疗的 T2 期 MIBC 患者。这种方法为 MIBC 患者的膀胱保留或新辅助治疗提供了一个有前景的新方向。