Outcomes of enfortumab vedotin and pembrolizumab for patients previously treated with immune checkpoint inhibitors in the UNITE study.

• DOI: 10.1200/jco.2025.43.5_suppl.867
• Publication Date: 2025-02-18T14:30:51Z
• Authors: Tanya Jindal; Cindy Y. Jiang; Omar Alhalabi; Fady Sidhom; Albert Jang; Dimitra Rafailia ...; Ishita Narula; Salvador Jaime-Casas; Michael Glover; Amanda Nizam; Shilpa Gupta; Mehmet Asim Bilen; Sumit Shah; Abhishek Tripathi; Petros Grivas; Jason Robert Brown; Arnab Basu; Matthew T. Campbell; Ajjai Shivaram Alva; Vadim S Koshkin
• Keywords: Immune checkpoint

867 Background: In trials testing enfortumab vedotin and pembrolizumab (EVP), prior treatment with immune checkpoint inhibitors (ICIs) was not permitted, resulting in a knowledge gap regarding efficacy of EVP patients (pts) previously treated ICIs. We hypothesized that would have pts ICI exposure. Methods: the retrospective UNITE study, we identified all to receiving EVP. The observed response rate (ORR) assessed evaluable who had imaging after ≥1 cycle following factors were evaluated assess effect on outcomes: type received (PD-1 vs PD-L1), other ICI, time from last start EVP, duration treatment, whether patient clinical benefit (SD/PR/CR) immediate therapy line it only line. ORR for these categories compared using logistic regression, while progression-free survival (PFS) overall (OS) analyzed log-rank test Cox proportional hazards model. Results: Among 220 across 10 US sites, 43 (20%) ICI. Median age 69 years; 34 (79%) men, 40 (93%) Caucasian, 27 (63%) pure urothelial carcinoma, 9 (21%) liver mets 31 (72%) ECOG PS 0/1. Of pts, 4 peri-operative setting (3 nivolumab, 1 pembrolizumab) 39 metastatic (19 pembrolizumab, 8 avelumab maintenance, 6 2 maintenance each atezolizumab, ipilimumab/nivolumab, durvalumab/tremelimumab, nivolumab/NKTR214). 48% (95% CI: - 66) 33 13 (39%) PR 3 (9%) CR; 30% SD as best (DCR 79%), 21% PD. After median follow-up 14 mos, PFS 6.9 mos 3.91 – 12.2) OS 15.4 8.7 NR). Outcomes by group are shown Table. Conclusions: Pts experienced high disease control rate. Results this multi-site study hypothesis-generating require prospective validation larger cohorts. Groups OR CI) p-value HR Type PD-L1) 2.15 (0.36 17.49) 0.4 0.72 (0.32 1.61) 0.59 (0.23 -1.52) 0.3 Prior 0.54 (0.12 2.23) 0.55 (0.26 1.16) 0.1 0.40 (0.15 1.02) 0.05 Time ICI* 1.01 (0.98 1.05) 0. 5 0.99 1.01) 0.9 0.98 (0.96 0.87 (0.74 0.98) (0.94 0.97 (0.89 Clinical PD) 0.50 (0.08 2.75) 0.70 (0.27 1.81) 0.5 0.89 (0.29 2.73) 0.8 Multiple lines 0.51 (0.11 2.29) 1.40 (0.57 3.44) 1.87 (0.54 6.43) 0.93 -5.82) 0.56 (0.20 1.57) 0.53 (0.17 1.64) *Continuous.