Bobek, Olivia

Background: Societal guidance recommends sequential noninvasive testing for metabolic dysfunction–associated steatotic liver disease (MASLD), using Fibrosis-4 (FIB-4) ≥1.3 as a gatekeeper before second-line assessment with the Enhanced Liver Fibrosis (ELF) score (<7.7 as a rule-out). The impact of this pathway design on the detection of fibrotic MASH remains uncertain. We aimed to evaluate the performance of guideline-endorsed sequential testing and to determine optimized ELF thresholds within alternative strategies. Methods: In this prospective study, patients with or at risk for MASLD underwent FIB-4, ELF testing, magnetic resonance elastography (MRE), and liver biopsy within 1 month. Fibrotic MASLD was defined as fibrosis stage ≥2 on histology or liver stiffness ≥3.1 kPa on MRE. Diagnostic performance of ELF was assessed, and sequential (ELF applied after FIB-4 ≥1.3) and concurrent (either test positive) testing strategies were compared. Results: Among 186 participants (median age 51 years; 69% women), fibrotic MASLD was present in 71 (38%). ELF demonstrated AUROC 0.77 (95% CI 0.70–0.84); the cohort-derived cutoff was 9.4 (80% sensitivity, 65% specificity). Lower cutoffs (8.7 and 7.7) increased sensitivity (≥90% and 100%) but low specificity (34% and 4%). FIB-4 ≥1.3 showed limited sensitivity (57%), resulting in 43% of fibrotic MASH cases being excluded from second-line testing. Sequential application of ELF, therefore, failed to overcome this sensitivity ceiling. A concurrent strategy using FIB-4 ≥1.3 or ELF ≥9.4 improved sensitivity to 87% with 64% specificity. Conclusions: Sequential FIB-4–based testing substantially limits the detection of fibrotic MASLD due to gatekeeping sensitivity constraints. Concurrent first-line testing with FIB-4 and ELF improves case identification, underscoring the importance of pathway design in optimizing noninvasive fibrosis assessment.

INTRODUCTION: The goal of this study was to identify nationwide access to transient elastography (TE), magnetic resonance elastography (MRE), and gastroenterologists. METHODS: We used public data from each test's manufacturer's website to identify the number of TE and MRE units in the United States. We used public data from the Health Resources and Services Administration to identify the number of gastroenterologists in the United States. RESULTS: Overall, 82.4% of US counties do not contain TE or MRE, and 69.2% do not contain a gastroenterologist. Two-thirds (67.4%) of US counties do not contain either elastography or a gastroenterologist. DISCUSSION: There is limited access to TE, MRE, and gastroenterologists in the United States.

5005 Background: Androgen receptor pathway inhibitors (ARPIs) may have distinct central nervous system (CNS) penetration and differential effects on cognition or quality of life (QOL). AFT-47, “ARACOG” is a prospective, randomized open-label phase 2 trial comparing objective and patient-reported cognitive and QOL outcomes between patients with metastatic hormone sensitive prostate cancer (mHSPC), metastatic castration-resistant prostate cancer (mCRPC) or non-metastatic castration-resistant prostate cancer (nmCRPC) treated with darolutamide (DAR) or enzalutamide (ENZ). Methods: Between 8/17/2021 and 3/11/2025, 111 pts were enrolled and randomized 1:1 to treatment with ENZ or DAR. CANTAB, a validated computer-based platform evaluating 5 cognitive domains (PALFAM-memory recall, SWM- spatial working memory, SSP-short-term visual memory, working memory, RVP-rapid visual processing, and OTSMCC- executive function), was performed at baseline, 12, 24, and 48 weeks. Crossover (Xover) was allowed at 12 or 24 weeks for significant pre-specified decline in cognitive testing or patient reported outcome measures (PROMs), or for CNS-associated adverse events, including falls. The primary endpoint was the percent change in the maximally changed cognitive domain (MCCD) from baseline to 24 weeks and was compared between groups with the Wilcoxon rank sum statistic. Patients crossing over prior to 24 weeks were evaluated at the time of Xover and analyzed with their randomized arm. Secondary endpoints included comparison of Xover rates. Results: Among 111 pts, 55 received DAR and 56 received ENZ; median age was 71, 83% White. 95 pts (48 DAR, 47 ENZ) were evaluable for the primary endpoint. Baseline CANTAB was similar between groups. Median cognitive change in MCCD between baseline and 24 weeks was -15.8% and -36.1% for the DAR and ENZ pts, respectively (p = 0.009) (Table). Individual cognitive domains suggest possible learning effect (increased scores) for DAR and are stable or show mild decline for ENZ treated patients at 24 weeks. 32 DAR (58%) and 33 ENZ (59%) participants were eligible for Xover by 24 weeks, and 23 pts crossed over by 24 weeks. All Xover was pts randomized to ENZ (crossed to DAR), with the most common causes being decline in objective (N = 14) or subjective (N = 11) cognitive testing. Conclusions: In this US randomized trial comparing DAR to ENZ, the primary endpoint of differential cognitive effects was met. ENZ showed significantly greater cognitive score decline than DAR at 24 weeks in the MCCD after treatment initiation. Learning effect was seen with DAR but not ENZ. Longer term follow-up of cognitive change and PROM analyses are ongoing. Clinical trial information: NCT04335682 . Percent change in maximally changed cognitive domain by treatment. DAR (N=48) ENZ (N=47) Wilcoxon Rank Sum Test Result CANTAB domain PALFAM SWM Degree of change -15.8 (-38.8, -2.6) -36.1 (-59.3, -16.7) P=0.009

Background The optimal management of biochemical recurrence (BCR) after radical prostatectomy (RP) remains controversial, particularly in the absence of clinical or radiographic evidence of disease. Salvage radiotherapy (SRT) remains standard of care, but it is unclear whether SRT benefits patients when modern imaging with a multiparametric magnetic resonance imaging (mpMRI) and prostate‐specific membrane antigen‐positron emission tomography/computed tomography (PSMA‐PET/CT) are negative for local recurrence. Retrospective data comparing SRT to observation for such patients is fraught with selection bias, underscoring the need for a prospective randomised controlled trial. Study Design and Methods The Biochemical Recurrence Irradiation or Observation (BRIO) is a randomised study under the DIVINE trial framework (NCT06378866) enrolling men with BCR (prostate‐specific antigen [PSA] level ≥0.2, up to 1.5 ng/mL) after RP with no radiographic evidence of recurrence on mpMRI and PSMA‐PET/CT. Major inclusion criteria include age ≥18 years, biochemically recurrent prostate cancer after RP with a PSA level between 0.2 and 1.5 ng/mL, and no local or metastatic recurrence on imaging. A total of 312 patients will be enrolled. Participants are randomised 1:1 to standard‐of‐care SRT followed by surveillance (Group A), or initial observation with subsequent image‐guided therapy at radiographic progression (Group B). Based on historical analysis, a total of 30 metastasis events provides 80% power to detect a significant improvement (hazard ratio 0.5 corresponding to a 5‐year metastasis‐free proportion of 80.7% in the control group and 89.8% in the experimental group with one‐sided type I error rate of 0.15). All participants undergo baseline blood collection to measure prostate cancer‐extracellular vesicles and cell‐free DNA for biomarker development. Participants are followed in a 16‐week cycle with serial PSA measurements, repeat imaging if PSA doubles, safety assessment, and patient‐reported outcomes. Endpoints The primary endpoint is distant recurrence‐free survival at 5‐years using a 12‐month landmark to mitigate bias arising from differing assessment schedules for patients receiving optional 6 months of androgen deprivation therapy. Key secondary outcomes include time to hormone therapy, quality of life measures, adverse effects, and novel blood and urine biomarkers. Conclusion The BRIO study will clarify the clinical benefit of immediate SRT vs observation with image‐guided intervention in mpMRI and PET‐negative BCR after RP.

TPS892 Background: Enfortumab Vedotin (EV) plus pembrolizumab (Pembro) is now first-line therapy for advanced urothelial carcinoma (UC), yielding ~30% complete response (CR) rates; nevertheless, most patients (pts) progress within 1 year and median overall survival (OS) remains < 3 years. In muscle invasive bladder cancer, local consolidation after systemic therapy improves outcomes, suggesting that residual, treatment-refractory intravesical disease drives relapse. We hypothesize that cytoreductive cystectomy/nephroureterectomy (CC/U)—with metastasis-directed therapy (MDT) as needed—can consolidate responses to EV/Pembro and extend benefit in regionally advanced or metastatic UC. CAST-AI prospectively evaluates this multimodal strategy and integrates correlative studies of exosomal Nectin-4 and circulating tumor DNA (ctDNA) from blood and urine as predictive/MRD biomarkers. Methods: CAST-AI is a phase II, decentralized single-arm trial enrolling pts with histologically confirmed UC of the bladder or upper urinary tract with ≥N1 and/or M1 disease and ECOG PS 0–2 who are potential surgical candidates (planned n = 75). Treatment: EV 1.25 mg/kg IV D1 & D8 + Pembro 200 mg IV D1 q21d, ≥4 cycles; MDT permitted any time pre-surgery. Response assessments occur q9 weeks (±4) to 18 months, then q12 weeks (±4). Surgical eligibility requires: (A) fitness for surgery; (B) complete or partial response (CR/PR) or, for select low-burden/unmeasurable disease, urologist-adjudicated candidacy; (C) all distant sites addressed; and (D) procedure in pt’s best interest. Post-CC/U maintenance EV/Pembro is encouraged per clinical discretion and guided by definitive surgical pathology results, which provide true pathologic staging often unattainable through imaging after systemic therapy. Primary endpoint: 12-month progression-free survival (PFS). Secondary endpoints: Objective response rate (ORR), CR rate, down-staging at CC/U, PFS, OS, and safety (using CTCAE). Exploratory endpoints: longitudinal exosomal Nectin-4 and ctDNA dynamics as MRD and early relapse indicators; tissue–blood–urine Nectin-4 concordance; pt-reported tolerability (using CIPN20). Key exclusions: > 20% variant histology or disallowed subtypes (e.g., micropapillary, plasmacytoid, sarcomatoid, neuroendocrine); prior chemotherapy for UC; contraindications to surgery/EV/ICI; or active uncontrolled comorbidities/infections. Status: Enrollment is open and ongoing, with 25 of 75 pts enrolled as of September 2025. The trial uses a decentralized model, allowing pts to receive EV/Pembro at their local facility, with central coordination, biospecimen shipping, and surgical evaluation at Mayo Clinic or affiliated sites. ClinicalTrials.gov: NCT06764095. Clinical trial information: NCT06764095 .

TPS277 Background: Recent advances in genomic sequencing have deepened our understanding of the molecular complexity of metastatic castration-resistant prostate cancer (mCRPC), revealing multiple actionable alterations that now inform biomarker-driven treatment strategies. Accordingly, germline and somatic tumor profiling is recommended for all patients with mCRPC. Beyond DNA aberrations, gene expression profiling can uncover additional therapeutic targets and pathway activations. The phase 2 PREDICT trial is leveraging both DNA and RNA alterations to guide rationally designed, biomarker-based therapeutic approaches for patients with mCRPC. Methods: This multi-center, multi-arm, biomarker-driven phase 2 umbrella trial is evaluating rationally selected therapies for patients with metastatic castration-resistant prostate cancer (mCRPC). The primary endpoint is objective response rate in patients with measurable disease, with secondary endpoints including radiographic progression-free survival, PSA response, time to first symptomatic skeletal event, overall survival, safety, and correlative biomarker analyses. Eligible patients must have progressive mCRPC of any histology, prior treatment with an androgen receptor pathway inhibitor (ARPI), and either prior or declined taxane chemotherapy, with both measurable and non-measurable disease permitted. Enrollment requires standard-of-care next-generation DNA sequencing from tissue or circulating tumor DNA performed in a CLIA-certified laboratory, and RNA-based allocation will use the CLIA-certified Caris MI Tumor Seek assay (whole exome and whole transcriptome sequencing) on tissue obtained within 12 months of study entry, with a real-time molecular tumor board reviewing results to confirm arm assignment. Patients with RB1 loss (DNA), an RB functional loss signature (RNA), or an NEPC signature (RNA) will receive the EZH1/2 inhibitor valemetostat; those with ≥2 of 3 tumor suppressor gene alterations (TP53, RB1, PTEN), FANC alterations (DNA), or SLFN11 overexpression (RNA) will receive cabazitaxel plus carboplatin; and those without study-defined alterations will receive physician’s choice of cabazitaxel, ARPI, or 177Lu-PSMA-617. The design permits incorporation of additional biomarker-defined arms, and up to 158 patients per arm (64 with measurable and 94 with non-measurable disease) will be accrued under a Simon two-stage minimax design, providing a one-sided type I error of 0.05 if the true response rate is 0.20 and 90% power if the response rate is 0.37 (Clinical trial information: NCT06632977). Clinical trial information: NCT06632977 .

Background: The rising incidence of PCNSL in the elderly represents an unmet need with an undefined standard approach [Villano Br J Cancer 2011]. High-dose methotrexate-based (HD-MTX) therapy is feasible and effective in older patients, but outcomes in this population remain poor. Despite high response rates to HD-MTX induction therapy, poor candidacy for intensive consolidative therapy results in transient disease control that may benefit from maintenance strategies [David Am J Hematol 2023]. Lenalidomide (len) has demonstrated activity in PCNSL even at low doses and represents a potential alternative to consolidation considering its extensive use in maintenance settings [Vu Br J Haematol 2019]. Anecdotal activity in PCNSL by checkpoint inhibitors such as nivolumab (nivo) has been reported [Nayak Blood 2017], and its immune response may be enhanced by len [Görgün Clin Cancer Res 2015]. A051901 evaluates the feasibility of the addition of len and nivo to rituximab (R) and HD-MTX as first line induction therapy followed by len-nivo maintenance in elderly patients with PCNSL not eligible for intensive consolidation. Study Design and Methods: This is a single-arm phase 1 multicenter US study (NCT04609046) conducted by the Alliance for Clinical Trials in Oncology with a traditional 3+3 design. Eligible patients are 18 years of age or older with untreated diffuse large B-cell lymphoma PCNSL diagnosed through brain biopsy or resection, or cerebrospinal (CSF) or vitreous fluid not considered candidates for high dose chemotherapy consolidation. This study is available to all eligible patients, regardless of race, gender, or ethnic origin. Patients must have adequate end-organ function including creatinine clearance of at least 50 mL/min. Use of systemic corticosteroids for disease control to be tapered after initiation of therapy is allowed. Induction consists of six 14-day cycles with rituximab 500 mg/m2 i.v. on day 1, HD-MTX 3g/m2 i.v. on day 2. In the most recent treatment schedule, a 5-day course of lenalidomide PO at different dose levels (dose level (DL) 1 = 10 mg, DL2 = 15 mg, DL3 = 20 mg) is initiated immediately after adequate clearance of HD-MTX. Once a maximum tolerated dose (MTD) of len is defined, a subsequent cohort will evaluate the addition of nivo 240 mg i.v. to the day 14 of the induction cycle of R-HD-MTX plus len at the MTD. Patients who present any clinical benefit from induction with at least stable disease by International PCNSL Collaborative Group response criteria are eligible for maintenance - twelve 28-day cycles of therapy with len 15 mg PO from day 1 to day 21 (regardless of dose during induction) +/- nivo 480 mg i.v. on day 1 (for those who received len and nivo during induction). The primary endpoint of the induction therapy is the MTD of len when given in combination with R-HD-MTX; the primary endpoint of maintenance is its feasibility, defined as the proportion of patients able to remain on maintenance for at least 6 cycles. As of July 2024, 16 patients have been enrolled with a maximum expected sample size of 47 patients with the assumption of 75% of patients being eligible to proceed with maintenance and 50% of those who begin maintenance not progressing in the first 6 cycles. Overall response, adverse events, progression-free and overall survival will be evaluated in all eligible patients with a focus on the outcome of patients treated at the MTD. For patients who consent to biobanking, diagnostic tissue, peripheral blood and CSF from different timepoints are collected and banked with planned exploratory analyses including whole exome sequencing, circulating tumor DNA, proteomics, metabolomics. Support: U10CA180821, U10CA180882. https://acknowledgments.alliancefound.org.