RC48-Antibody-Drug Conjugate in Metastatic Urothelial Carcinoma: A Multicenter Real-World Study in China

Real -world study of RC48-ADC for metastatic urothelial carcinoma (mUC) is lacking. We retrospectively collected data of 103 mUC patients receiving RC48 in China. Objective response rate and disease control rate were 50.5% and 79.6%, the median progression-free survival was 6 months, and severe treatment-related adverse events is uncommon. Therefore, administration of RC48 for real -world patients is both effective and safe. Objectives: RC48 is an antibody-drug conjugate (ADC) that targets HER2. In China, RC48 is approved for patients with HER -2 -positive metastatic urothelial carcinoma (mUC) who have failed at least platinum-based chemotherapy. This study aimed to evaluate RC48 for mUC in a cohort of real -world patients. Materials and Methods: We retrospectively collected data from 103 mUC patients from 12 centers between July 2021 and August 2023 in China. RC48 alone or with immunotherapy was administered until disease progression, intolerable toxicity, death, or other reasons. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and incidence of treatment-related adverse events (TRAEs) were evaluated. Results: The median age of the patients was 68 years, and 68.0% were men. Twentynine (28.2%) patients received RC48 alone; 73 (70.9%) received RC48 combination therapy. The response rates were as follows: complete response in 2 (1.9%) patients, partial response in 50 (48.5%) patients, stable disease in 30 (29.1%) patients. The ORR was 50.5%. In patients with >= 80 years, Eastern Cooperative Oncology Group (ECOG) performance status >= 2 and creatinine clearance rate (CCr) < 30 mL/min, the ORR was 75%, 48.6%, and 40.0%, respectively. The median PFS was 6 (3.9-8.1) months, and the median OS was not reached. The most reported TRAEs were peripheral sensory neuropathy (53.4%), alopecia (42.7%), asthenia (38.8%), decreased appetite (35.9%) and weight loss (35.9%) and TRAE did not increase in patients with poor condition or impaired renal function. Conclusion: Administration of RC48 for real -world patients is both effective and safe. mUC patients can benefit from RC48-based therapy, regardless of their poor condition or impaired renal function.