Outcomes with sacituzumab govitecan (SG) in patients (pts) with advanced urothelial carcinoma (aUC) and variant histologies (VH): Analysis of the UNITE study.

• DOI: 10.1200/jco.2024.42.4_suppl.667
• Publication Date: 2024-01-29T21:06:41Z
• Authors: Amanda Nizam; Tanya Jindal; Cindy Y. Jiang; Omar Alhalabi; Matthew P. Davidsohn; Dimitra Rafailia ...; Rafee Talukder; Charles B Nguyen; Eugene Oh; Amy K Taylor; Mehmet Asim Bilen; Arnab Basu; Deepak Kilari; Hamid Emamekhoo; Shilpa Gupta; Petros Grivas; Joaquim Bellmunt; Matthew T Campbell; Ajjai Shivaram Alva; Vadim S Koshkin
• Keywords: Metastatic Urothelial Carcinoma

667 Background: SG is approved in pts with aUC refractory to platinum-based chemotherapy (PBT) and checkpoint inhibitor therapy (CPI). Data on outcomes subtype/variant histologies (VH) are limited. We examined SG-treated the UNITE study hypothesized that would be similar between pure urothelial histology (pUC) any VH component. Methods: a multi-site retrospective of treated (Tx) targeted agents, such as enfortumab vedotin (EV) SG. Pts who received monotherapy were included this analysis. Observed response rate (ORR) was assessed by investigators at each site for evaluable scans after ≥ 1 cycle using χ 2 logistic regression. Progression-free overall survival (PFS, OS) from start KM method Cox proportional hazards model. Results: Among 633 total UNITE, 116 11 US sites. Median age 70; 79 (68%) male; 97 (84%) Caucasian; 86 (74%) ECOG PS 0/1; 84 (72%) lower tract tumor; 90 (78%) visceral or bone mets; 48 (41%) Bellmunt score ≥2; 72 (62%) had pUC 44 (38%) VH, including 33 (28%) UC predominant (<50% VH) (9%) variant (≥50% VH). For prior therapy, 109 (94%) >2 lines; 75 (65%) PBT; 102 (88%) CPI; EV. time metastatic diagnosis 18.6 months (mo) (0.9-84.5). follow up 10.6 mo (8.5-15.4). 1.6 (0.2-14.7). ORR 24% (20/84); median PFS OS 3.7 (95% CI 3.0-4.6) 6.7 5.3-10.8). (n ≥1) included: squamous (SQH) (19, 16%), micropapillary (9, 8%), plasmacytoid (8, 7%), adenocarcinoma (3, 3%), neuroendocrine (NE) (2, 2%). In ORRs: (3/14), (1/4), (0/6), (2/3), NE (1/2). No significant differences observed SQH (Table). Conclusions: appear have clinical VH. Responses across different Limitations include low power, tumor heterogeneity, lack central pathology/scan review, selection confounding biases. These hypothesis-generating findings suggest activity post-PBT, CPI, EV but should validated larger cohorts adequate sample size specific longer up. [Table: see text]