PD10-01 DISEASE-FREE SURVIVAL WITH LONGER FOLLOW-UP FROM THE CHECKMATE 274 TRIAL OF ADJUVANT NIVOLUMAB IN PATIENTS AFTER SURGERY FOR HIGH-RISK MUSCLE-INVASIVE UROTHELIAL CARCINOMA

391 Background: The standard of care (SOC) for patients (pts) with MIUC is radical surgery ± cisplatin-based neoadjuvant chemotherapy (chemo), but many pts are cisplatin-ineligible. There is no conclusive evidence supporting adjuvant chemo in pts who did not receive neoadjuvant chemo and in those with residual disease after neoadjuvant cisplatin. This phase 3 trial of adjuvant nivolumab (NIVO) vs placebo (PBO) in pts with MIUC after radical surgery ± neoadjuvant cisplatin (CheckMate 274) aims to address an unmet need in these pts. We report the initial results. Methods: This is a phase 3, randomized, double-blind, multicenter trial of NIVO vs PBO in pts with high-risk MIUC (bladder, ureter, or renal pelvis) after radical surgery. Pts were randomized 1:1 to NIVO 240 mg Q2W or PBO for ≤ 1 year of adjuvant treatment. Pts had radical surgery within 120 days ± neoadjuvant cisplatin or were ineligible/declined cisplatin-based chemo, evidence of UC at high risk of recurrence per pathologic staging, were disease-free by imaging, and ECOG PS ≤ 1. Primary endpoints: disease-free survival (DFS) in all randomized pts (ITT population) and in pts with tumor PD-L1 expression ≥ 1%. DFS was stratified by nodal status, prior neoadjuvant cisplatin, and PD-L1 status. Non–urothelial tract recurrence-free survival (NUTRFS) in ITT pts and in pts with PD-L ≥ 1% is a secondary endpoint. Safety is an exploratory endpoint. Results: In total, 353 pts were randomized to NIVO (PD-L1 ≥ 1%, n = 140) and 356 pts to PBO (PD-L1 ≥ 1%, n = 142). The primary endpoint of DFS was met in ITT pts (median follow-up, 20.9 mo for NIVO; 19.5 mo for PBO) and in pts with PD-L1 ≥ 1%. DFS and NUTRFS were improved with NIVO vs PBO in both populations (Table). DFS improvement with NIVO was generally consistent across subgroups. Grade 3–4 treatment-related adverse events (TRAEs) occurred in 17.9% and 7.2% of pts in the NIVO and PBO arms, respectively. Conclusions: NIVO demonstrated a statistically significant and clinically meaningful improvement in DFS vs PBO for MIUC after radical surgery, both in ITT pts and pts with PD-L1 ≥ 1%. AEs were manageable and consistent with previous reports. These results support adjuvant NIVO as a new SOC for pts with MIUC with high risk for recurrence despite neoadjuvant chemo or those ineligible for and/or declining cisplatin-based chemo. Clinical trial information: NCT02632409 . Research Sponsor: Bristol Myers Squibb[Table: see text]

4585 Background: In the CheckMate 274 trial, disease-free survival (DFS) was significantly improved with nivolumab (NIVO) vs placebo (PBO) both in intent-to-treat (ITT) patients (pts) (hazard ratio [HR], 0.70; 98.22% confidence interval [CI], 0.55–0.90; P < 0.001) and in pts with tumor programmed death ligand 1 (PD-L1) expression ≥ 1% (HR, 0.55; 98.72% CI, 0.35–0.85; P < 0.001). We report results for the subgroup of pts with bladder cancer, the most predominant type of urothelial carcinoma. Methods: CheckMate 274 is a phase 3, randomized, double-blind trial of adjuvant NIVO vs PBO in high-risk muscle-invasive urothelial carcinoma (bladder, ureter, renal pelvis) after radical resection. Pts were randomized 1:1 to NIVO 240 mg intravenously every 2 weeks or PBO for ≤ 1 year of adjuvant treatment and stratified by nodal status, prior neoadjuvant cisplatin, and tumor PD-L1 expression. Pts had radical resection ± neoadjuvant chemotherapy and were at high risk of recurrence on final pathologic staging. Primary endpoints were DFS in ITT pts and in pts with PD-L1 ≥ 1%. Non–urothelial tract recurrence-free survival (NUTRFS) was a secondary endpoint, and distant metastasis-free survival (DMFS) was an exploratory endpoint. This exploratory analysis focused on the subgroup of pts with muscle-invasive bladder cancer (MIBC) after radical resection. Results: Of 709 randomized pts in the trial, 560 had MIBC (NIVO, n = 279; PBO, n = 281). With a minimum follow-up of 11.0 months, a DFS benefit was observed with NIVO vs PBO in these pts, regardless of tumor PD-L1 expression (Table). DFS probability at 12 months in all MIBC pts was 66% with NIVO and 45% with PBO. DFS was improved with NIVO vs PBO across subgroups according to age, sex, ECOG performance status, nodal status, and PD-L1 expression status. Improvement in NUTRFS and DMFS with NIVO vs PBO was also observed (Table). Grade 3–4 treatment-related adverse events occurred in 17% and 6% of pts in the NIVO and PBO arms, respectively. Conclusions: Improvement in DFS was observed with NIVO over PBO in pts with MIBC after radical resection regardless of tumor PD-L1 expression. The DFS benefit was observed in all prespecified subgroups. These results further support adjuvant NIVO as a standard-of-care treatment for pts with high-risk MIBC after radical resection ± neoadjuvant cisplatin-based chemotherapy. Clinical trial information: NCT02632409. [Table: see text]

LBA02-08 RESULTS FROM THE EXTENDED FOLLOW-UP IN PATIENTS WITH MUSCLE-INVASIVE BLADDER CANCER IN THE CHeckMATE 274 TRIAL

658 Background: In the phase 3, randomized, double-blind CheckMate 274 trial, adjuvant NIVO demonstrated statistically significant and clinically meaningful disease-free survival (DFS) benefit vs PBO in pts with high-risk MIUC after radical surgery (RS) ± prior neoadjuvant cisplatin-based chemotherapy (NAC). With extended 3-y median follow-up, continued improvements in DFS were seen with NIVO vs PBO in the primary efficacy populations (intent-to-treat [ITT], tumor programmed death ligand 1 [PD-L1] expression ≥ 1%) and in pts with MIBC. Early trends in interim OS favored NIVO vs PBO in ITT and tumor PD-L1 ≥ 1% pts. Here we report additional efficacy outcomes for pts with MIBC. Methods: Pts were randomized 1:1 to NIVO 240 mg every 2 wk or PBO for ≤ 1 y of adjuvant treatment, stratified by tumor PD-L1 expression, nodal status, and prior NAC. Primary endpoints were DFS in ITT and tumor PD-L1 expression ≥ 1% pts. OS in ITT and PD-L1 ≥ 1% pts was a secondary endpoint. Analysis of MIBC pts was exploratory. MIBC OS data are from preplanned interim analyses of ITT and PD-L1 ≥ 1% pts. OS follow-up is ongoing as the prespecified statistical boundaries for significance in ITT and PD-L1 ≥ 1% pts were not crossed at the time of these analyses. Results: Of 709 randomized pts (ITT), 560 (79%) had MIBC (NIVO, n = 279; PBO, n = 281); 284 (51%) of MIBC pts had prior NAC. With median follow-up of 36.1 mo (ITT), DFS improvement with NIVO vs PBO was consistent between all pts with MIBC (hazard ratio [HR] 0.63) and those with (HR 0.58) and without prior NAC (HR 0.69; Table). For OS, HRs favored NIVO vs PBO in all pts with MIBC (HR 0.70) and the tumor PD-L1 ≥ 1% subgroup (HR 0.48), as well as in pts with MIBC with (HR 0.74) and without prior NAC (HR 0.67). Safety was consistent with previous data in ITT pts; no new safety signals were identified. Conclusions: With 3-y median follow-up, consistent benefit in DFS was observed with NIVO vs PBO in all MIBC pts and across prior NAC subgroups. The HR for OS favored NIVO in all MIBC pts, in those with PD-L1 ≥ 1%, and regardless of prior NAC status. These results continue to support adjuvant NIVO as a standard of care for high-risk MIUC and MIBC, potentially providing an opportunity for a curative outcome. Clinical trial information: NCT02632409 . NIVOn NIVOMedian(95% CI), mo PBOn PBOMedian(95% CI), mo HR (95% CI) DFS All MIBC 279 25.6 (19.2–41.8) 281 8.5 (7.3–13.7) 0.63 (0.51–0.78) With prior NAC 142 19.6 (15.6–48.2) 142 8.3 (5.6–11.2) 0.58 (0.43–0.79) No prior NAC 137 25.9 (19.2–51.5) 139 13.7 (7.8–22.1) 0.69 (0.50–0.94) OS All MIBC 279 NR (45.0–NE) 281 39.9 (29.8–52.1) 0.70 (0.55–0.90) PD-L1 ≥ 1% 113 NR (NE–NE) 117 37.6 (26.9–NE) 0.48 (0.29–0.77) With prior NAC 142 55.2 (41.8–NE) 142 40.2 (28.8–53.7) 0.74 (0.53–1.03) No prior NAC 137 NR (40.7–NE) 139 37.7 (28.7–65.2) 0.67 (0.47–0.95) NE, not estimable; NR, not reached.

491 Background: CheckMate 274 demonstrated a significant improvement in disease-free survival (DFS) with nivolumab (NIVO) versus placebo (PBO) both in the intent-to-treat population (hazard ratio [HR], 0.70; 98.22% confidence interval [CI], 0.55–0.90; P < 0.001) and in patients (pts) with tumor programmed death ligand 1 (PD-L1) expression ≥ 1% assessed by the tumor proportion score (TPS) (HR, 0.55; 98.72% CI, 0.35–0.85; P < 0.001). An exploratory subgroup analysis showed a trend toward a DFS benefit with NIVO in pts with TPS < 1% (0.82; 95% CI, 0.63–1.06). To further characterize the relationship between PD-L1 expression and NIVO efficacy, we report an analysis of DFS based on PD-L1 expression in both tumor and immune cells using the combined positive score (CPS). Methods: CheckMate 274 is a phase 3, randomized, double-blind, multicenter trial of NIVO versus PBO in pts with high-risk muscle-invasive urothelial carcinoma after radical surgery. Pts were randomized 1:1 to NIVO 240 mg or PBO every 2 weeks intravenously for 1 year of adjuvant treatment. The primary endpoints of the study are DFS in the intent-to-treat population and in pts with TPS ≥ 1%. The Dako PD-L1 IHC 28-8 pharmDx assay was used to evaluate TPS. CPS was determined retrospectively from previously stained immunohistochemistry slides using the CPS algorithm. CPS was calculated as the number of both PD-L1 positive tumor and immune cells divided by the number of viable tumor cells in the evaluable tumor area, multiplied by 100; TPS was similarly calculated with the number of PD-L1 positive tumor cells as the numerator. This analysis only included pts with both quantifiable CPS and TPS. Results: Of the 629 pts with quantifiable TPS and CPS, 249 (40%) had TPS ≥ 1% (NIVO, n = 124; PBO, n = 125), 380 (60%) had TPS < 1% (NIVO, n = 191; PBO, n = 189), 557 (89%) had CPS ≥ 1 (NIVO, n = 281; PBO, n = 276), and 72 (11%) had CPS < 1 (NIVO, n = 34; PBO, n = 38). Within TPS < 1% pts, 81% (n = 309) had CPS ≥ 1. The number of pts and the DFS outcomes in pts with TPS ≥ 1% and CPS ≥ 1 are shown in the Table. In pts with TPS < 1% who also had CPS ≥ 1, median DFS (95% CI) was 19.2 (15.6–33.4) months with NIVO versus 10.1 (8.2–19.4) months with PBO. The HR for NIVO versus PBO in these pts was 0.73 (95% CI, 0.54–0.99). Conclusions: This exploratory analysis of PD-L1 expression by CPS showed a higher proportion of pts with CPS ≥ 1 than TPS ≥ 1%, and that most pts with TPS < 1% had CPS ≥ 1. In the CPS ≥ 1 subgroup, median DFS with NIVO was more than double that with placebo. These results support the conclusion that pts with TPS < 1% also benefit from adjuvant NIVO. Clinical trial information: NCT02632409. [Table: see text]

LBA443 Background: The 2 primary endpoints of the CheckMate 274 trial were met as nivolumab (NIVO) improved disease-free survival (DFS) versus placebo (PBO) in the intent-to-treat (ITT) population and in patients with tumor programmed death ligand 1 (PD-L1) expression ≥ 1%. We report extended follow-up data. Methods: CheckMate 274 is a phase 3, double-blind trial of adjuvant NIVO versus PBO for high-risk muscle-invasive urothelial carcinoma (MIUC) (bladder, ureter, or renal pelvis) after radical resection. Patients were randomly assigned 1:1 to NIVO 240 mg every 2 wk or PBO for ≤ 1 year of treatment. Patients had pathologic evidence of UC at high risk of recurrence and Eastern Cooperative Oncology Group performance status (ECOG PS) ≤ 1. Primary endpoints were DFS in ITT patients and in patients with PD-L1 ≥ 1%. DFS was also analyzed in prespecified subgroups. Overall survival and non–urothelial tract recurrence-free survival (NUTRFS) in ITT patients and in patients with PD-L1 ≥ 1% were secondary endpoints. Distant metastasis-free survival (DMFS) and safety were exploratory endpoints. Results: There were 353 patients randomly assigned to NIVO (PD-L1 ≥ 1%, n = 140) and 356 to PBO (PD-L1 ≥ 1%, n = 142). With median follow-up of 36.1 months (minimum follow-up, 31.6 months), median DFS was 22.0 months with NIVO versus 10.9 months with PBO in ITT patients and 52.6 months with NIVO versus 8.4 months with PBO in patients with PD-L1 ≥ 1% (Table). DFS benefit was seen in most subgroups analyzed including age, sex, ECOG PS, nodal status, prior cisplatin-based chemotherapy, and PD-L1 status. NUTRFS and DMFS benefits with NIVO versus PBO were also observed in both populations (Table). Grade 3–4 treatment-related adverse events occurred in 18.2% and 7.2% of patients in the NIVO and PBO arms, consistent with the primary analysis. Overall survival will be assessed at a future database lock. Conclusions: With extended follow-up, NIVO continued to show DFS, NUTRFS, and DMFS benefits versus PBO. The hazard ratio (HR) for DFS and NUTRFS in PD-L1 ≥ 1% patients and for DMFS in both ITT and PD-L1 ≥ 1% patients also continued to improve versus the primary analysis. No new safety signals were identified. These results further support adjuvant NIVO as a standard of care for high-risk MIUC after radical resection. Clinical trial information: NCT02632409 . [Table: see text]

565 Background: NIVO has shown promise as an adjuvant treatment for MIUC. In the CheckMate 274 trial, NIVO achieved a significant improvement in disease-free survival compared to placebo in MIUC pts at high risk of recurrence following radical surgery. However, it is unclear how treatment decisions are made in the RW setting and what factors drive providers in selecting either NIVO or CHEMO as adjuvant treatment. We compared the baseline demographic and clinical characteristics of pts with MIUC who received adjuvant NIVO to those who received adjuvant platinum-based CHEMO in the RW setting. Methods: This retrospective medical chart review included pts diagnosed with stage II-IIIB MIUC who initiated treatment with NIVO or CHEMO within 120 days of radical resection between 9/1/2021 and 11/25/2022. Treating oncologists from a US nationally representative network abstracted pts’ data from electronic medical charts. Pts’ demographic and clinical characteristics were assessed. Results: Age, sex, and race were similar across cohorts (Table). Pts who received adjuvant NIVO (n = 158) vs CHEMO (n = 88) were more likely to have ECOG-PS≥ 2 at treatment initiation (24.1% vs 17.1%; P = 0.02), and more likely to receive PD-L1 testing (Not tested: 36.1% vs. 47.7%; P < 0.0001) and have PD-L1 expression levels ≥ 50% (13.9% vs 1.1%; P < 0.0001). A higher proportion of pts who received NIVO vs CHEMO had diabetes with chronic complications (15.8% vs 5.7%; P = 0.02) and hypertension (20.9% vs 6.8%; P = 0.004), and were determined to be cisplatin-ineligible (41.8% vs 25%; P = 0.007), predominately based on creatinine clearance (< 60 mL/min: 48.7% vs. 34.1%; P = 0.002) and poor PS (13.9% vs. 4.6%; P = 0.07); rheumatologic disease was less common among the NIVO cohort (1.9% vs 11.4%; P = 0.002). Conclusions: This RW analysis demonstrated that pts with MIUC who received adjuvant NIVO had greater baseline disease severity and comorbidities than those who received adjuvant CHEMO. These findings suggest that patient characteristics influence treatment selection of adjuvant therapy in this patient population, highlighting the need to adjust for baseline characteristics in future comparative analyses.[Table: see text]

Perspectives on Adjuvant Therapy in Renal Cell Carcinoma

4003 Background: In CheckMate 577 (NCT02743494), NIVO demonstrated a significant and clinically meaningful improvement in disease-free survival (DFS; primary endpoint) vs placebo (PBO) and was well tolerated in patients (pts) with resected (R0) stage II/III EC/GEJC who received neoadjuvant CRT and had residual pathologic disease. Median DFS doubled with NIVO vs PBO (22.4 vs 11.0 months; HR 0.69; 96.4% CI 0.56–0.86; P = 0.0003). Serious treatment-related adverse events (TRAEs) and TRAEs leading to discontinuation were reported for < 10% of pts with NIVO and 3% with PBO. Methods: Pts were randomized 2:1 to NIVO 240 mg or PBO Q2W for 16 weeks, followed by NIVO 480 mg or PBO Q4W. Here, we present additional efficacy, safety, and quality-of-life (QoL) data from CheckMate 577. Results: 794 pts were randomized (NIVO, 532; PBO, 262). Distant recurrence was reported for 29% vs 39% and locoregional recurrence for 12% vs 17% of pts in the NIVO vs PBO groups, respectively. Median distant metastasis-free survival was 28.3 vs 17.6 months with NIVO vs PBO (HR 0.74; 95% CI 0.60–0.92). Median progression-free survival 2 (PFS2; time from randomization to progression after subsequent systemic therapy, initiation of second subsequent systemic therapy, or death, whichever is earlier) was not reached with NIVO vs 32.1 months with PBO (HR 0.77; 95% CI 0.60–0.99). TRAEs with potential immunologic etiology (select TRAEs; sTRAEs) reported for NIVO are presented in the table. Results for the FACT-ECS and FACT-G7 showed similar trends for QoL improvement from baseline for NIVO and PBO during treatment and maintained benefit post-treatment. Conclusions: Adjuvant NIVO demonstrated clinically meaningful efficacy, an acceptable safety profile, and maintained QoL, providing further support for its use as a new standard of care for pts with resected EC/GEJC who received neoadjuvant CRT with residual pathologic disease. Clinical trial information: NCT02743494. [Table: see text]

TPS4622 Background: Pts with muscle-invasive UC of the bladder or upper genitourinary tract who undergo radical cystectomy or nephroureterectomy are at high risk for cancer recurrence if residual pathologic advanced disease is identified at the time of surgery. Emerging data demonstrates that pts with minimal residual disease following curative-intent surgery, as detected by circulating tumor DNA (ctDNA), may be at a particularly high risk of UC recurrence. Adjuvant N has been approved post curative-intent surgery, with or without prior neoadjuvant chemotherapy (NAC), in pts with muscle-invasive UC at high risk of recurrence based on results of the CheckMate 274 study, which demonstrated a disease free survival (DFS) at 6 months of 74.9% with N versus 60.3% with placebo. SG is an antibody-drug conjugate with activity in UC. Evaluating intensification of adjuvant therapy in order to reduce the chance of metastasis development is of great interest. Methods: This is an IRB-approved, prospective, multi-center, single-arm phase 2 study of combination therapy with SG plus N. To be eligible, pts must have documented muscle-invasive UC, with variant and mixed histology allowed, except small cell. Pts must have undergone curative-intent surgery within 180 days prior to study therapy initiation and be radiographically free of metastasis. Pts who received prior NAC must have T2-T4 or node positive disease on surgical pathology, while those without NAC must have pathologic T3-T4 or node positive disease. Pts must also be ineligible or refuse platinum-based adjuvant chemotherapy. Additional selected eligibility criteria include creatinine clearance of at least 30 ml/min and adequate bone marrow function. If eligible for the study, pts will receive SG 7.5 mg/kg on day 1 and 8 combined with Nivolumab 360 mg on day 1 given every 21 days for 4 cycles, followed by single-agent Nivolumab 480 mg on day 1 given every 28 days for an additional 11 cycles. Use of growth factor support is allowed, as per institutional practice. Primary study endpoint is investigator-assessed DFS at 6 months. Secondary study endpoints include DFS, distant metastasis-free survival (MFS), overall survival (OS), incidence of grade 3 or higher adverse events, rate of ctDNA clearance in baseline ctDNA positive patients as well as exploratory biomarker analysis. The sample size calculation was based on a one-sided one sample test for exponential hazard rate when the probability of DFS at 6-months in the experimental group is 85% and in the historical control group is 75% in order to detect a hazard ratio of 0.565 with a power of 80% at a 0.05 significance level. Projected study accrual time is 24 months and per pt follow-up time is 36 months. Out of 23 anticipated pts, 3 have been enrolled to date since study activation in 11/2024. Clinical trial information: NCT06682728 .

167 Background: NIVO is the first adjuvant therapy to provide a statistically significant and clinically meaningful improvement in disease-free survival (DFS) versus PBO in resected EC/GEJC following neoadjuvant chemoradiotherapy as demonstrated by CheckMate 577. NIVO was well tolerated with an acceptable safety profile. This analysis provides additional information on the exploratory HRQoL endpoints in this clinical trial. Methods: The effect of NIVO versus PBO on HRQoL, including general and disease-related symptoms, functioning, disease burden, and overall QoL, was assessed using FACT-E and EQ-5D-3L patient-reported outcome (PRO) questionnaires administered at baseline (BL), every 4 weeks during the 12-month treatment period, and at post-treatment follow-up visits (up to 2 years after last dose). Longitudinal change from BL in PRO scores over 12 months was assessed using descriptive statistics. Additionally, mixed model for repeated measures and time to deterioration analyses evaluated the difference between treatment with NIVO and PBO (data not shown). Results: 794 pts with EC/GEJC were randomized 2:1 to NIVO (n = 532) or PBO (n = 262). PRO completion rates were ≥ 95% at BL and ~ 90% at 12 months on treatment. Mean (SD) BL HRQoL scores were similar between treatment arms for the FACT-E total score (NIVO: 133.40 [20.97]; PBO: 134.03 [20.40]); esophageal cancer subscale (ECS; NIVO: 50.2 [9.3]; PBO: 50.1 [8.9]); EQ-5D Visual Analogue Scale (NIVO: 70.4 [22.3]; PBO: 69.1 [24.1]); and EQ-5D Utility Index (NIVO: 0.820 [0.179]; PBO: 0.831 [0.163]) based on the UK value set. Descriptive analyses showed a trend for increases from baseline at most time points through week 49 for both NIVO and PBO treatment groups for FACT-E total score, ECS, and EQ-5D Visual Analogue Scale and Utility Index. Conclusions: Preliminary results from CheckMate 577 demonstrated that pts on NIVO treatment showed trends of improvement in both esophageal-specific and general HRQoL. Similar trends were also observed in pts treated with PBO over 1 year. Pts treated with NIVO did not experience a reduction in HRQoL, further supporting clinical data to demonstrate treatment benefit and tolerability for adjuvant NIVO in pts with resected EC/GEJC. Clinical trial information: NCT02743494.

Estimating the Impact of Adjuvant Treatment With Nivolumab on Long-Term Survivorship Rates Compared With Surveillance in Muscle Invasive Urothelial Carcinoma: Mixture Cure Modeling Analyses of Disease-Free Survival From the Phase 3 CheckMate 274 Trial.

Adjuvant immunotherapy in high-risk muscle-invasive urothelial cancer: an updated meta-analysis of randomized controlled trials

Chemotherapy + PD-1/PD-L1 Blockade Should Be the Preferred Option in the Neoadjuvant Therapy of NSCLC

Objectives: Historically, African-American/Black patients with bladder cancer have worse clinical outcomes compared with White/Caucasian patients. In the CheckMate 274 trial, nivolumab demonstrated a significant improvement in disease-free survival compared with placebo among patients with MIUC at high risk of recurrence following radical surgery; however, African-American/Black patients were underrepresented (< 1%). The objective of this analysis was to describe the characteristics and outcomes of MIUC patients treated with adjuvant nivolumab across different racial subgroups in a real-world setting. Methods: This US retrospective medical chart review included African-American/Black and White/Caucasian patients with MIUC treated with adjuvant nivolumab following radical resection between 01-Sep-2021 and 10-Sep-2022. Patient characteristics and outcomes were abstracted from the medical charts by treating oncologists. Patient characteristics and landmark survival estimates based on Kaplan-Meier analyses were summarized descriptively. Results: The analysis included 223 patients (African-American/Black: 62; White/Caucasian: 161). A numerically higher proportion of African-American/Black vs White/Caucasian patients, respectively, was male (74.2% vs 66.5%), less than 60 years old (27.4% vs 20.5%), unemployed (16.1% vs 5.6%), and had Medicaid at therapy initiation (14.5% vs 6.2%). Similar proportions in both groups had ECOG performance status 0-1 (82.3% vs 82.6%), received neoadjuvant therapy (58.1% vs 56.5%), and completed adjuvant therapy (67.7% vs 66.5%). The median follow-up time (12.5 months vs 13.1 months) and median duration of adjuvant therapy (11.0 months vs 11.3 months) were comparable. Similar estimates were observed for 12-month overall survival (96.7% vs 91.4%), 12-month disease-free survival (88.3% vs 88.4%), and 12-month distant metastasis-free survival (88.3% vs 88.4%). Conclusions: Despite higher rates of socio-economic risk factors among African-American/Black patients, this real-world study suggests similar effectiveness of adjuvant nivolumab among MIUC patients across African-American/Black and White/Caucasian patient populations. Citation Format: Regina Barragan-Carrillo, Alexander Chehrazi-Raffle, Bruce Feinberg, William S. John, Taavy A. Miller, Sarah Lucht, Prathamesh Pathak, Emily Bland, Sarah Gordon, JaLyna Laney, Andrew J. Klink, Hedyeh Ebrahimi, Nisha Singh, Carmelo Alonso, Miraj Patel, Lisa Rosenblatt, Xin Yin. Racial differences in characteristics and outcomes of adjuvant nivolumab for muscle-invasive urothelial carcinoma (MIUC) in the real-world setting [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr A008.