Pustake, M

e16564 Background: Urothelial carcinoma (UC) predominantly affects older adults with a high burden of comorbidities, particularly chronic kidney disease (CKD), which affects 30–40% of patients at diagnosis and is more prevalent in advanced disease. Enfortumab vedotin plus pembrolizumab (EV+P) has become a frontline standard for advanced UC; however, patients with moderate-to-severe CKD were underrepresented in pivotal trials. Enfortumab vedotin targets Nectin-4 expressed in renal tubular epithelium, and immune checkpoint inhibitors are associated with immune-mediated nephrotoxicity, raising concern for renal vulnerability in patients with reduced renal reserve. Real-world data evaluating renal and clinical outcomes of EV+P in patients with baseline CKD are limited. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network, identifying adult patients with UC treated with EV+P between January 2020 and December 2025. Baseline CKD status (stages 3–5; eGFR < 60 mL/min/1.73 m²) was determined by diagnostic codes and laboratory data obtained prior to EV+P initiation.Patients were stratified into CKD and non-CKD cohorts. Propensity score matching (1:1) was performed for demographics, comorbidities, laboratory values, and prior therapies. Outcomes assessed within 180 days of treatment initiation included overall survival (OS), major adverse kidney events (MAKE; composite of acute kidney injury, dialysis initiation or dependence, or death), and selected treatment-related toxicities. Kaplan–Meier and Cox proportional hazards models were used. Results: After matching, 386 patients were included in each cohort (median age 75 years), with well-balanced baseline characteristics (all post-matching standardized mean differences < 0.1). Prior to matching, patients with CKD had a higher burden of cardiovascular comorbidities. Baseline renal function differed by design, with lower mean eGFR and higher serum creatinine in the CKD cohort. Overall survival was similar between CKD and non-CKD cohorts (HR 0.96; 95% CI, 0.69–1.35; p = 0.83), with 180-day survival rates of 79.9% and 79.3%, respectively. Patients with CKD had a higher incidence of MAKE, reflected by lower 180-day event-free survival (49.4% vs 59.1%; HR 1.41; 95% CI, 1.13–1.76; p = 0.002). Treatment-related toxicities were also more frequent in the CKD cohort (HR 1.35; 95% CI, 1.05–1.74; p = 0.020), with a higher mean number of toxicity events (4.3 vs 3.4). Conclusions: In this large real-world analysis, EV+P use was associated with comparable short-term overall survival in UC patients with and without CKD but with higher rates of renal events and treatment-related toxicities among patients with baseline CKD. These findings support the use of EV+P in select UC patients with CKD, with close monitoring of renal function and treatment-related toxicity.

2028 Background: Patients with EGFR-mutated non–small cell lung cancer (NSCLC) frequently develop BM, and CNS progression is a common mode of failure on earlier-generation EGFR tyrosine kinase inhibitors (TKIs). After TKI failure in the setting of BM, optimal next-line systemic therapy remains uncertain, particularly regarding the comparative effectiveness of targeted escalation, immunotherapy (IO)-based regimens, and chemotherapy. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network. We identified EGFR-mutated NSCLC patients treated with first- or second-generation EGFR TKIs who subsequently developed metachronous BM and initiated next-line systemic therapy between 2015 and 2025. Patients with leptomeningeal disease prior to earlier-generation TKI exposure were excluded. Treatment strategies were categorized as targeted escalation with osimertinib, IO-based therapy (immune checkpoint inhibitor with or without chemotherapy), or chemotherapy alone. The index date was defined as initiation of next-line systemic therapy. Propensity score matching was performed for pairwise comparisons. The primary endpoint was overall survival (OS) at 180 days. Restricted mean survival time (RMST) through 181 days was evaluated as a sensitivity analysis. Baseline covariate balance after matching was assessed using standardized mean differences, with values <0.10 indicating adequate balance. Results: After propensity score matching with adequate baseline balance, osimertinib was associated with significantly lower 180-day mortality compared with chemotherapy (24.5% vs 33.2%; hazard ratio [HR] 0.69, 95% CI 0.47–1.00). Comparisons between osimertinib and IO-based therapy showed numerically lower 180-day mortality with osimertinib (26.0% vs 32.6%; HR 0.79, 95% CI 0.54–1.15), but this difference did not reach statistical significance. Similarly, IO-based therapy was not associated with a statistically significant survival advantage compared with chemotherapy alone (31.7% vs 37.5%; HR 0.78, 95% CI 0.58–1.06). RMST analyses for death over 181 days were directionally consistent with hazard ratio–based results, with modest, non-significant differences in mean survival time. Conclusions: In EGFR-mutated NSCLC patients with metachronous brain metastases after earlier-generation TKI failure, targeted escalation with osimertinib was associated with significantly lower 180-day mortality compared with chemotherapy. IO-based approaches demonstrated intermediate, directionally favorable but non-significant outcomes relative to both osimertinib and chemotherapy. These real-world findings support guideline recommendations prioritizing next-generation TKIs and help inform systemic treatment sequencing in a CNS-enriched population where prospective data remain limited.

2036 Background: Patients with oncogene-driven metastatic non–small cell lung cancer (NSCLC) treated with CNS-penetrant tyrosine kinase inhibitors (TKIs) frequently develop brain metastases (BM) while continuing targeted therapy, and outcomes of adding local CNS-directed therapy in this setting are not well defined. We evaluated outcomes associated with local CNS therapy after post-TKI BM diagnosis. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network. Adults with NSCLC treated with osimertinib or lorlatinib who subsequently had a coded diagnosis of BM (ICD-10 C79.31) at least 1 month after TKI initiation and evidence of continued TKI use were included. Patients were stratified by receipt of CNS-directed local therapy (SRS/SBRT or neurosurgery) within 3 months of the index BM diagnosis versus no local therapy. The primary outcome was all-cause mortality within 180 days of the index event. Secondary outcomes included hospitalization and systemic corticosteroid use. Cohorts were balanced using 1:1 propensity score matching on demographics, comorbidities, extracranial disease, laboratory values, and TKI exposure. Survival analyses were performed, and proportional hazards assumptions were validated using Schoenfeld residuals (p>0.05). Results: Among 1,157 eligible patients, 1,053 matched pairs were generated. Within 180 days of the index brain metastasis diagnosis, mortality was lower among patients who received local CNS therapy compared with those who did not (10.9% vs 18.1%), corresponding to a hazard ratio (HR) for death of 0.54 (95% CI 0.43–0.68; p<0.001). Survival probabilities at 180 days were 88.7% in the local therapy cohort and 80.2% in the no local therapy cohort. Hospitalization within 180 days occurred in 20.3% of patients receiving local therapy and 22.4% of those without local therapy (p=0.24), with a nonsignificant trend toward delayed hospitalization (HR 0.84, 95% CI 0.69–1.01). Systemic corticosteroid use was common and similar between groups (61.3% vs 59.4%; p=0.40), with no significant difference in time to steroid initiation. In an osimertinib-only sensitivity analysis, 180-day mortality was 10.5% among patients receiving local CNS therapy compared with 19.4% among those without local therapy (HR 0.48, 95% CI 0.37–0.61; p<0.001). Conclusions: In this multi-institutional real-world cohort of patients with NSCLC receiving osimertinib or lorlatinib who developed BM, receipt of local CNS-directed therapy within 3 months was associated with lower 6-month mortality compared with continuation of targeted therapy alone, with consistent findings in an osimertinib-only sensitivity analysis. These results suggest a potential survival benefit of local CNS intervention in selected patients, while acknowledging residual confounding related to intracranial disease burden and clinical indication.