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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.

e16017 Background: Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer and remains one of the deadliest malignancies worldwide, largely due to late-stage diagnosis. Early-stage PDAC is frequently asymptomatic, limiting opportunities for timely detection and intervention. We aimed to develop prognostic models using routinely acquired pre-diagnostic clinical data to identify individuals at high risk for PDAC prior to clinical manifestation. Methods: We conducted a retrospective study of patients treated at Mayo Clinic sites in Rochester, MN; Phoenix, AZ; and Jacksonville, FL between January 2011 and February 2023. The cohort included 1,151 patients with PDAC and 3,745 noncancer controls. CT scans were standardized to axial abdominal acquisitions with slice thickness between 0.8–3.0 mm. Radiology reports were de-identified, normalized, and parsed into structured sections (Indications, Findings, Impression), with an additional pancreas-specific section aggregating pancreas-related sentences. Demographic and clinical variables, e.g., age, sex, race, etc., were encoded using a templated sentence representation. All textual inputs were embedded using a Sentence-BERT model. A multimodal deep learning survival model was developed to integrate CT imaging, radiology report embeddings, and demographic features. The model was trained using a negative log-likelihood loss to estimate patient-specific PDAC risk scores. Model performance was assessed using the concordance index (C-index). Internal validation included patients from MN and AZ sites, while external validation used the FL cohort. Results: We evaluated unimodal (imaging, text, and demographics) and multimodal inputs. Fusion of imaging, radiology report, and demographic features achieved the highest performance, with internal and external validation C-indices of 0.885 (95% CI, 0.856–0.908) and 0.751 (95% CI, 0.719–0.783), respectively. Subgroup analysis by tumor location demonstrated differential performance. For pancreatic head tumors, internal and external C-indices were 0.916 (95% CI, 0.841–0.960) and 0.778 (95% CI, 0.730–0.823). For pancreatic body tumors, C-indices were 0.954 (95% CI, 0.897–0.997) internally and 0.929 (95% CI, 0.897–0.953) externally. For pancreatic tail tumors, internal and external C-indices were 0.903 (95% CI, 0.830–0.974) and 0.789 (95% CI, 0.689–0.874). Conclusions: A multimodal deep survival model leveraging pre-diagnostic CT imaging, radiology report embeddings, and demographic data can effectively identify individuals at high risk for PDAC prior to clinical diagnosis. Differences in performance were observed across pancreatic head, body, and tail tumors. This approach highlights the potential of opportunistic cancer risk stratification from routine imaging to enable earlier detection and targeted intervention strategies.

e13656 Background: Effective multidisciplinary cancer care is bottlenecked by the cognitive burden of synthesizing fragmented electronic health records across different specialties. Current AI tools often function as isolated chatbots rather than integrated workflow assistants. We developed and validated "OncoSphere AI," an Agentic AI multidisciplinary clinical workflow support tool designed to autonomously orchestrate the multidisciplinary review process by deconstructing complex cases into domain-specific insights. Methods: OncoSphere AI is a novel, multi-agent large language model–driven platform that simulates a multidisciplinary tumor board for cancer care. The architecture uses a parallel reasoning framework in which eight virtual specialty agents—Medical Oncology, Radiation Oncology, Surgical Oncology, Pathology, Radiology, Pharmacy, Clinical Research, and Nurse Navigation—independently analyze structured and unstructured patient data against specialty specific guidelines and contemporary peer-reviewed literature. System performance was assessed via built-in telemetry (task completion, latency, inter-agent agreement) and blinded review by eight expert oncologists using a structured survey to rate data extraction fidelity, guideline concordance, safety, and clinical utility compared with standard manual review. Results: The study cohort (n=20, median age 59.5 years; 55% female) had a median of 2.5 (range 0-7) prior lines of therapy and multiorgan metastatic disease (median: 2, range 1–4), including lung, breast, gastrointestinal (CRC, pancreatic, hepatobiliary), and genitourinary (prostate, renal) malignancies. OncoSphere AI demonstrated high workflow utility (mean rating: 4/5) and strong extraction fidelity, with more than 90% of biomarker extractions rated as a “perfect match” by expert reviewers. Operational efficiency gains were substantial with AI processing averaged 4.7 minutes per case versus 29.3 minutes for manual review, corresponding to an 84% reduction in time (p<0.001). System telemetry revealed adaptive compute behavior, with the platform autonomously allocating 1.73-fold more reasoning tokens to complex, refractory cases than to standard scenarios. Safety review identified only one critical contraindication issue in a heavily pretreated, multi-line setting. Conclusions: OncoSphere AI effectively automates the clinical “perception layer,” consistently transforming heterogeneous longitudinal data into decision-grade insights with high fidelity and marked time savings. By operating as a coordinated ensemble of domain-specialized AI agents rather than a single generic model, it offers a scalable approach to reduce physician cognitive burden and to standardize guideline-concordant care planning in diverse, heavily pretreated oncology populations.

Abstract Maternal iron deficiency (ID) affects nearly 85% of all pregnancies worldwide by the third trimester and is strongly linked with maternal morbidity, poor birth outcomes, and cognitive and behavioral developmental deficits in children. Despite its burden on maternofetal health, no guidelines exist for routine screening of ID in pregnant individuals in the United States. The World Health Organization uses a diagnostic (ie, nonscreening) ferritin threshold of 15 μg/L for ID in the first trimester of pregnancy, with no guidance for the second and third trimesters. Routine screening for ID in pregnancy could identify a large proportion of mothers who remain undiagnosed and untreated under the current clinical status quo. Accordingly, we conducted, to our knowledge, the first cost-effectiveness analysis of ferritin-based ID screening in pregnant women in the United States, comparing thresholds of (1) 30 μg/L vs (2) 15 μg/L vs (3) no screening from a modified US societal perspective accounting for wages lost to infusion time, infusion administration costs, and the cost of annual hematology follow-up. We found that screening at 30 μg/L was the preferred strategy across extensive base-case, threshold, and sensitivity analyses and across all examined willingness-to-pay thresholds, with an incremental cost-effectiveness ratio of $34 000/quality-adjusted life year (QALY; 95% credible interval, $32 000-$36 200/QALY) compared with no screening. No parameter variation changed this outcome, and screening at 30 μg/L was favored in 100% of 10 000 Monte Carlo iterations. Population-level regular second- and third-trimester screening for ID using physiologically informed ferritin ranges should be considered for all pregnant women in the United States.

7569 Background: MAIA and CEPHEUS trials demonstrated that daratumumab (Dara) with standard of care (SOC) VRd or Rd significantly improved clinical outcomes versus SOC in TIE NDMM. Here we describe efficacy and safety in TIE pts from both trials by age and baseline (BL) frailty using the latest data cuts. Methods: Pts were randomized 1:1 to DRd (n=368) or Rd (n=369) in MAIA and 1:1 to DVRd (n=144) or VRd (n=145) in CEPHEUS. Progression-free survival (PFS), complete response or better (≥CR), overall MRD negativity (neg) at 10 -5 with ≥CR, sustained MRD neg with ≥CR (confirmed MRD neg ≥12 ± 1 months [mo] apart without MRD positivity in between), and safety were assessed by age (<70, 70–<75, or ≥75 years [y]) and BL frailty (assessed by IFM simplified frailty score: 0–1, non-frail; ≥2, frail). Results: Median follow-up was 64.5 mo in MAIA and 76.0 mo in CEPHEUS. In MAIA, 155 (21%) pts were <70 y, 261 (35%) 70–<75 y, and 321 (44%) ≥75 y; 341 (46%) pts were frail, 88.0 % of whom were ≥70 y. In CEPHEUS TIE pts, 70 (24%) pts were <70 y, 133 (46%) 70–<75 y, and 86 (30%) ≥75 y; 83 (29%) pts were frail, 86% of whom were ≥70 y. DRd or DVRd improved PFS, MRD neg rates, sustained MRD neg rates, and ≥CR rates vs Rd or VRd arms across age and frailty subgroups in both trials (Table). Safety was consistent with established individual drug profiles, and adverse event rates were generally comparable across treatment arms and subgroups within both trials. Additional data on patient-specific factors relevant to these subgroups will be presented. Conclusions: Dara-based regimens improved efficacy outcomes across subgroups in MAIA and CEPHEUS trials, reinforcing Dara-based regimens as SOC in TIE NDMM regardless of age or frailty. These data offer clinically relevant insights to help guide treatment selection for TIE pts. Clinical trial information: NCT03652064 ; NCT02252172 . PFS, hazard ratio (95% CI) ≥CR rate, % MRD neg with ≥CR (10 -5 ) rate, % Sustained MRD neg with ≥CR (10 -5 ) rate, % Age/ Frailty status MAIA* CEPHEUS** MAIA* CEPHEUS ** MAIA* CEPHEUS** MAIA* CEPHEUS ** <70 y 0.35 (0.21–0.56) 0.60 (0.31–1.18) 56.4 vs 31.2 85.7 vs 68.6 35.9 vs 11.7 74.3 vs 42.9 25.6 vs 3.9 62.9 vs 28.6 70–<75 y 0.64 (0.45–0.89) 0.60 (0.37–0.99) 56.2 vs 31.3 77.9 vs 69.2 36.2 vs 12.2 55.9 vs 47.7 20.8 vs 5.3 45.6 vs 38.5 ≥75 y 0.59 (0.44–0.79) 0.46 (0.22–0.94) 44.4 vs 28.6 80.5 vs 44.4 26.9 vs 9.9 58.5 vs 26.7 13.8 vs 3.1 43.9 vs 15.6 Frail 0.64 (0.48–0.85) 0.62 (0.32–1.18) 44.8 vs 33.1 72.9 vs 54.3 25.6 vs 13.0 56.3 vs 34.3 15.7 vs 4.1 39.6 vs 17.1 Non-frail 0.48 (0.36–0.64) 0.51 (0.34–0.78) 56.6 vs 27.5 84.4 vs 63.6 37.8 vs 9.5 63.5 vs 41.8 21.4 vs 4.0 54.2 vs 32.7 *MAIA: DRd vs Rd; **CEPHEUS: DVRd vs VRd.

564 Background: HER2+ ILC is rare (~5% of ILC), with limited data on long-term adjuvant trastuzumab outcomes. We investigated late recurrence and immune landscapes of HER2+ ILC vs invasive ductal carcinoma (IDC) in the phase III NCCTG N9831 trial (NCT00005970) and a real-world cohort. Methods: We evaluated 3304 early-stage HER2+ breast cancer patients (pts) enrolled in N9831 (122 ILC, 3182 IDC). Recurrence-free survival (RFS) and overall survival (OS) were estimated (Kaplan-Meier) and compared using multivariable Cox regression adjusting for age, tumor size, grade, hormone receptor (HR), and nodal status. Findings were validated in a real-world cohort of HER2+ pts (Caris Life Sciences CODEai platform). Immune microenvironments were profiled by WTS deconvolution (Quantiseq). Real-world overall survival was calculated from trastuzumab start to last contact. Results: In N9831, ILC pts were older (median 54 vs 49 y), more ER+ (74.6% vs 51.4%), and had more N3 disease (25.4% vs 12.7%) compared to IDC. ILC pts derived a comparable magnitude of benefit from adjuvant trastuzumab compared to the overall population (HR 0.58 vs 0.67). However, long-term outcomes diverged: while the 5-year RFS was similar (77.1% vs 82.7%), ILC pts experienced a steep decline between years 5-15 (77.1% to 57.7%; ~20% decline) vs IDC (82.7% to 72.7%; ~10% decline) after multivariable Cox analysis (Table). In the real-world early/advanced cohort (n=1328; 26 ILC vs 1302 non-ILC [subset IDC n=595]) treated with trastuzumab-based therapy, ILC pts had worse mOS (33.7 vs 68.6 m, HR 2.01, 95%CI 1.00-4.07, p=0.04) compared to non-ILC. However, there was no statistically significant difference when compared specifically to IDC (HR 1.77, 95% CI 0.87-3.61, p=0.11). ILC had: i) numerically lower tumor mutation burden (TMB)-high (4.2% vs 9.5%, p=0.38); ii) higher infiltration of B cells, Tregs, and M2 macrophages (p<0.05); iii) upregulated MHC class II expression (HLA-DOA, p<0.05); and iv) downregulated proliferative and DNA repair pathways (E2F, G2M, MYC; FDR <0.25) compared to non-ILC. Conclusions: HER2+ ILC carries late recurrence risk despite initial trastuzumab benefit. The unique immune landscape (Treg/M2 macrophage enrichment and lower proliferative signatures) distinguishes HER2+ ILC from IDC, highlighting the need for tailored strategies. Long-term RFS and OS in HER2-positive ILC vs IDC (N9831 trial). Population N 5-year% (95% CI) 10-year% (95% CI) 15-year% (95% CI) ILC 122 RFS 77.13% (69.9, 85.1) OS 84.04% (77.7, 90.9) RFS 70.57% (62.7, 79.4) OS 76.0% (68.7, 84.2) RFS 57.67% (44.2, 75.1) OS 65.22% (56.6, 75.2) IDC 3182 RFS 82.71% (81.4, 84.1) OS 90.18% (89.1, 91.2) RFS 77.45% (75.9, 78.9) OS 81.81% (80.4, 83.2) RFS 72.68% (70.77, 74.6) OS 76.68% (75, 78.4)

4500 Background: BM occur in ~30% of RCC pts and are associated with poor survival and symptomatic skeletal events (SSEs). Radium-223, an alpha-emitting bone-seeking radioisotope, prolongs survival in advanced prostate cancer. A pilot study of radium-223 with VEGF tyrosine kinase inhibitors (TKI) in RCC with BM showed safety and early efficacy (McKay, CCR, 2018). Cabozantinib is a TKI that showed efficacy in BM. RADICAL (NCT04071223) was designed to investigate cabozantinib ± radium-223 in RCC with BM. Methods: This open label multicenter study enrolled RCC pts with ≥1 symptomatic BM not previously irradiated and Karnofsky performance status ≥60%. Prior therapies were allowed; non-clear cell population was limited to 20%. Randomization was 1:1 to cabozantinib with (Arm A) or without (Arm B) radium-223, stratified by osteoclast-targeted therapy (OTT), prior therapy, baseline opioid use, and IMDC risk. In Arm A, cabozantinib was 40 mg daily cycle 1, 60 mg thereafter if tolerated; radium-223 was 1.49 microcurie/kg IV every 28 days for 6 doses. In Arm B, cabozantinib was 60 mg daily. The primary endpoint was SSE-free survival (SSE-FS). Secondary endpoints were safety, objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). The study was designed with 85% power to detect improvement in 6-month SSE-FS from 65% to 78% (one-sided α=0.05), with planned interim futility analysis at 50% of expected events. Results: From 12/2019 to 9/2025, 90 pts were enrolled and evaluable for the interim analysis. Median age was 63 years; 74.4% male, 90.0% White, 83.3% clear cell histology. 11.1% were treatment naïve, 80.0% received OTT, 51.1% had baseline opioid use. IMDC risk was 16.7% favorable, 68.9% intermediate, 14.4% poor. Median cabozantinib dose was 31.4 mg (Arm A) and 40.0 mg (Arm B); median radium-223 cycles was 6. Median follow-up was 13.1 (range 0.1-49.4) months with 50 events, 17 SSEs (Arm A: 10; Arm B: 7) and 33 deaths (Arm A: 13; Arm B: 20). Outcomes are in Table. 71 pts were evaluable for response. ORR was 22.2% (Arm A), 22.9% (Arm B). Any grade treatment-related adverse events were 97.7% (Arm A), 93.2% (Arm B); grade ≥3 were 65.9% (Arm A), 56.8% (Arm B). The trial closed after interim analysis as SSE-FS did not meet the prespecified futility boundary (HR≤1). Conclusions: Radium-223 did not improve the primary endpoint of SSE-FS when added to cabozantinib but a numerical prolongation in OS was observed. Combination treatment was safe. Alternative radiotherapeutics warrant investigation in RCC. Clinical trial information: NCT04071223 . Interim efficacy analysis. Arm Median(95% CI) HR (95% CI) Stratified SSE-FS A 17.9 (15.0-NE) 1.24 (0.62-2.48) B 17.6 (10.9-NE) Unstratified SSE-FS A 17.9 (15.0-NE) 0.90 (0.51-1.59) B 17.6 (10.9-NE) OS A 32.2 (17.9-NE) 0.77 (0.42-1.41) B 21.3 (12.3-NE) Stratified PFS A 11.0 (5.8-17.4) 1.39 (0.72-2.66) B 11.2 (9.0-18.5)

4559 Background: Baseline QOL has been linked to survival in mRCC therapy clinical trials (Cella, 2024); however, there is a paucity of prospectively collected real-world QOL data across front-line management strategies. We used data from ODYSSEY to examine the relationship between baseline QOL and early death. Methods: ODYSSEY is a multi-site, prospective observational study of 468 US pts with mRCC. Pts must have mRCC (any histology); have no prior systemic therapy (ST) or be within 3 months of starting ST; and follow up at a PCORnet study site. Exclusion criteria include treatment for cancer except mRCC. The primary objective is to determine patterns of change in QOL and symptom burden of pts with mRCC. Early death was defined as death within 12 months post-enrollment. All pts with non-missing FKSI-19 or FKSI-DRS at enrollment were included. Cumulative event probabilities as a function of time were stratified by either < or ≥ median QoL value and plotted as a step function vs time since enrollment to create cumulative event curves. To determine association between QoL at enrollment and early death, separate Cox proportional hazards models (unadjusted and adjusted) for time-to-first-event as a function of baseline QoL were fit. The adjusted model controlled for the following baseline covariates: IMDC risk (favorable vs intermediate or poor), histology (clear cell vs non). Results: As of 1/5/26, 468 pts were enrolled; 425 had non-missing FKSI-19 or FKSI-DRS at enrollment (329 immediate ST, 96 deferred ST [DST]). ST included 129 IO-IO, 108 IO-TKI, 92 Other. DST included 57 Active Surveillance, 22 Local Therapy Planned, 17 Other/Missing. 209 and 190 pts have < median FKSI-19 (score = 59) and FKSI-DRS (score = 29), respectively; 216 and 235 pts have ≥ median FKSI-19 and FKSI-DRS, respectively. Those below the median have lower rates of nephrectomy, worse IMDC risk and KPS, shorter time since RCC diagnosis, and higher rates of bone metastasis (all p<0.05). Cumulative event probabilities for death at 12 months are 21% and 7% in those < and ≥ median baseline FKSI-19, respectively; and 21% and 7% in those < and ≥ median baseline FKSI-DRS, respectively. For FKSI-19, the unadjusted hazard ratio (HR) for early death is 0.55 (95% CI: 0.43 – 0.70; p<0.001) and adjusted HR is 0.65 (0.49 – 0.85; p = 0.002) per 1 SD higher score. For FKSI-DRS, the unadjusted HR for early death is 0.57 (95% CI: 0.46 – 0.71; p<0.001) and adjusted HR is 0.66 (0.51 – 0.86; p =0.002) per 1 SD higher score (higher score indicates better QOL). Conclusions: Across management strategies in our ODYSSEY cohort of systemic therapy naïve mRCC patients, better baseline QOL was associated with better survival. This is to our knowledge the largest reported real world mRCC cohort with prospectively collected PROs. Future analyses will focus on association of outcomes with longitudinal PROs. Clinical trial information: NCT04919122 .

3146 Background: The MTA-cooperative PRMT5 inhibitor BMS-986504 selectively binds to the PRMT5-MTA complex, a synthetic lethal target in MTAP -del cancer cells, while sparing MTAP –wild-type normal cells. In the phase 1 CA240-0007 study, BMS-986504 was well tolerated and had antitumor activity in pts with MTAP -del advanced solid tumors (ORR, 23%; median DOR, 10.5 mo). BMS-986504 also demonstrated dose-dependent reductions in plasma symmetric dimethylarginine (SDMA) levels, a PD biomarker of PRMT5 inhibition. Here, we report expanded PD and genomic analyses and initial results of exploratory proteomic analyses from CA240-0007. Methods: Pts with advanced, unresectable, or metastatic solid tumors with homozygous MTAP -del received BMS-986504 (50–800 mg) in 3-wk cycles. Analyses of SDMA levels and proteomic profiles from paired plasma samples (baseline and C2D1) were performed using mass spectrometry and SomaScan 11K, respectively. Tumor genomic information was extracted from local pathology reports. ORR was assessed per RECIST v1.1. Results: Among 78 pts with paired samples at data cutoff (22 Sept 2025; median f/u, 15.9 mo), dose-dependent reductions were seen in plasma SDMA levels, with the greatest reductions at 400 mg QD (median, 60.3%; n = 31) and 600 mg QD (median, 60.3%; n = 23). Proteomic pathway enrichment analysis demonstrated downregulation of PI3K/Akt/mTOR, Myc target, cell cycle, and DNA damage repair (DDR) pathways with BMS-986504 on C2D1 (n = 87), consistent with the expected effect of PRMT5 inhibition; a trend toward deeper modulation of PRMT5-regulated pathways was observed at higher doses. No proteins at baseline (n = 94) were found to be significantly associated with ORR (false discovery rate > 0.05). Responses in clinically evaluable pts with NSCLC (n = 33) or PDAC (n = 35) were observed regardless of EGFR , KRAS , or TP53 status. In pts with NSCLC, STK11 and SMARCA4 alterations were numerically higher in nonresponders. No gene alterations were associated with response in PDAC, except GABRA6 alterations (n = 2, both responders). A trend toward higher ORRs was seen in pts with alterations in DDR genes ( CHEK2, FANCD2, XRCC4 , and/or MSH2 ), consistent with the role of PRMT5 in DDR via regulation of mRNA splicing. ctDNA analysis will be presented. Conclusions: BMS-986504 demonstrated robust dose-dependent PD effects in pts with advanced solid tumors in plasma SDMA and proteomic analyses. Downregulation of PRMT5-regulated pathways was observed with BMS-986504 treatment. Response was seen regardless of EGFR, KRAS , and TP53 alterations in NSCLC or PDAC, and DDR gene alterations were associated with improved response. These findings further support the MOA of BMS-986504 and its ongoing investigation in the phase 2/3 MountainTAP-9, -29, and -30 studies as a potential treatment option in pts with MTAP -del advanced solid tumors. Clinical trial information: NCT05245500 .

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.