Arora, Sukeshi Patel

e16449 Background: Pancreatic cancer (PC) carries a dismal 5-year survival of < 12%, and no FDA-approved agents exist for primary prevention. PC risk is strongly linked to obesity, diabetes, and chronic inflammation. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) directly target obesity-driven inflammatory pathways, reduce metabolic stress, and modulate signaling pathways (PI3K/AKT/mTOR) that drive cancer apoptosis. Based on this biological rationale, we conducted the first large-scale real-world study to evaluate the safety and efficacy of GLP-1RA for primary prevention of PC in high-risk patients. Methods: Leveraging a large real-world database (TriNetX), we identified patients aged 18-90 years with ≥1 PC risk factor (tobacco use, obesity, type 2 diabetes, alcohol use disorder, chronic pancreatitis, first-degree relative with PC, genetic susceptibility to PC) based on ICD-10 codes. Patients were stratified by GLP-1RA exposure into two cohorts: Cohort A (GLP-1RA users with ≥ 2 months of prescriptions) and Cohort B (controls). The primary endpoint was incident PC, and the secondary endpoints were adverse events related to GLP-1RAs. Patients with outcomes before the study window were excluded. Propensity score matching adjusted for confounders. Multivariate logistic regression was used to estimate odds ratios for categorical outcomes, and the Cox proportional hazards model was used to estimate hazard ratios for time-to-event outcomes. Subgroup and sensitivity analyses were employed to validate the strength of our results. Results: Median follow-up was 3,397 days for GLP-1RA users and 2,531 days for controls. Demographics were balanced between cohorts (mean age 42 years; 74% White, 15% Black; 72% female). Among 572,330 high-risk patients (286,165 per cohort), PC incidence was significantly lower among GLP-1RA users (0.05%; 134/286,165) than among non-users (0.13%; 362/286,097), with a 2.6-fold reduction in the absolute incidence of PC among high-risk patients (NNT of 1,255). GLP-1RA use was associated with a 71% reduction in PC incidence (HR 0.289; 95% CI 0.237–0.352). GLP-1RA use was associated with an increased risk of gastrointestinal adverse events, including nausea/vomiting (HR 1.108; 95% CI 1.096–1.121), abdominal pain (HR 1.081; 95% CI 1.066–1.097), diarrhea (HR 1.199; 95% CI 1.182–1.217), and constipation (HR 1.159; 95% CI 1.143–1.176). Conclusions: GLP-1RA use significantly reduced PC incidence by 71% in high-risk patients, the strongest real-world signal yet for a pharmacologic prevention of this lethal malignancy. Although the absolute incidence remained low, the magnitude of the risk reduction underscores the transformative potential of GLP-1RA in preventive oncology. These findings address a critical unmet need in pancreatic oncology. Prospective mechanistic and randomized studies are warranted to validate these associations.

10522 Background: Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality. While antiviral and metabolic therapies have reduced incidence, scalable pharmacologic strategies for primary prevention (PP) remain a critical unmet need. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have demonstrated preclinical antitumor activity and the potential to mitigate hepatic lipotoxicity while promoting metabolic reprogramming to stabilize cirrhosis. However, while chemoprevention signals are observed in metabolic dysfunction-associated steatotic liver disease (MASLD) and type 2 diabetes, the efficacy of GLP-1RAs for PP across diverse liver disease etiologies remains underexplored. To address this gap, we conducted a global, multicenter analysis on the efficacy and safety of GLP-1RAs for the PP of HCC in a pan-etiology high-risk cohort. Methods: A retrospective cohort study was conducted using the TriNetX database (150M patients across 108 health organizations). Adults 18–90 years at elevated HCC risk with ≥ 1 risk factor (chronic viral hepatitis, cirrhosis, MASLD, alcohol use disorder, or hereditary liver disorders) were identified. Cohort A (≥3 months of GLP-1RA) was propensity score-matched 1:1 with Cohort B (non-users) on demographics, HbA1c, BMI, and MELD-Na scores. The primary endpoint was incident HCC, and secondary endpoints were incidence of gastrointestinal (GI) side effects. We employed a 3-month lag period to mitigate immortal time bias. Time-to-event outcomes were assessed via Kaplan-Meier analysis and Cox proportional hazards models. Sensitivity & subgroup analyses were performed to confirm robustness across non-metabolic etiologies. Results: After matching, 592,718 patients were analyzed (296,359 per cohort). Median follow-up was 2,450 days for GLP-1RA users vs 2,114 days for non-users. GLP-1RA use was associated with a 73% reduction in incident HCC (140/296,345 events vs 432/296,198) [HR 0.271 (0.224-0.328)], (NNT=1,015). Notably, the protective effect was most pronounced in non-diabetics [HR 0.179 (0.140-0.229)] and lean patients (BMI < 29) [HR 0.161 (0.103-0.252)]. Risk reductions were sustained across all etiologies, including alcohol liver disease (HR 0.379), cirrhosis (HR 0.456), chronic viral hepatitis (HR 0.477), and MASLD (HR 0.605). GLP-1RA use was associated with a significant increase in GI adverse events. Conclusions: GLP-1RA use was associated with a 73% reduction in incident HCC, consistent across subgroups. The enhanced benefit in non-diabetic and lean cohorts suggests a direct anti-neoplastic mechanism independent of weight loss or glycemic control. The NNT of 1,015 highlights the substantial public health impact of GLP-1RA therapy in preventing a high-mortality malignancy. These findings warrant prospective validation.

Objective: This study aimed to evaluate the characteristics, clinical outcomes, and resource use of patients with unresectable hepatocellular carcinoma (uHCC) treated with first-line (1L) atezolizumab plus bevacizumab (A+B) at five United States (US) institutions: the Mayo Clinic, Houston Methodist, Moffitt Cancer Center, Mays Cancer Center, and University of Arizona. Methods: Treating oncologists extracted data from medical charts of patients with uHCC who were treated with A+B after 1 January 2019. Real-world progression-free survival (rwPFS) and overall survival (OS) were assessed using the Kaplan–Meier method for the overall cohort and for a “trial-like” subgroup with characteristics similar to those in the IMbrave150 trial (Eastern Cooperative Oncology Group Performance Status [ECOG PS] 0–1, Child–Pugh [CP] class A, albumin–bilirubin grade 1–2). Results: Of the 300 patients in the overall cohort (median age of 68 years; 12% ECOG PS ≥ 2; 73% CP A; 26% CP B; median follow-up of 8.7 months), the median rwPFS was 6.8 (95% confidence interval [CI]: 5.8, 8.4) months, and the median OS was 14.4 (95% CI: 12.3, 18.2) months. In the trial-like subgroup (n = 194), the median rwPFS was 8.8 (95% CI: 7.6, 12.1) months and the median OS was 19.5 (95% CI: 14.6, 24.7) months. A significantly lower proportion of patients with CP A compared with CP B (39.7% vs. 73.4%) experienced hospitalization within one year of A+B initiation, whereas hospitalizations due to treatment-related adverse events were similar. Conclusions: This study provides insights into the real-world effectiveness of 1L A+B in a diverse US patient cohort, with results from trial-like patients supporting the reproducible efficacy of A+B in clinical practice.

AbstractBackgroundExternal‐beam radiation (EBRT) is a noninvasive therapeutic alternative to transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). The objective of this study was to conduct a systematic review and meta‐analysis of prospective randomized clinical trials to assess the clinical efficacy of EBRT versus TACE for HCC as either a definitive monotherapy or as a bridge to transplantation/surgery.MethodsA systematic review and meta‐analysis were performed to include prospective randomized trials comparing EBRT versus TACE. Data was analyzed with random and fixed‐effects models. The inconsistency index (I2) was chosen to assess heterogeneity. Three publications were included with a total of 142 patients. Outcomes included local control (LC), overall survival (OS), progression‐free survival (PFS), and occurrences of grade ≥3 toxicity. Comparisons are reported as hazard ratios (HRs) or risk ratios (RRs) with 95% confidence intervals (CIs).ResultsThere were three randomized trials that met inclusion criteria. The EBRT was delivered in three to 15 fractions with a total dose between 30 and 75 gray(Gy). EBRT was associated with significantly improved LC (HR, 0.16; 95% CI, 0.08–0.34; I2 = 0%) and PFS (HR, 0.37; 95% CI, 0.23–0.60; I2, 0%) compared with TACE. There was no significant difference between EBRT and TACE in OS (RR, 0.79; 95% CI, 0.51–1.22; I2 = 0%) or grade ≥3 toxicity (RR, 0.86; 95% CI, 0.31–2.37; I2 = 57%). None of the analyses had statistically significant heterogeneity.ConclusionsCompared with TACE, EBRT yields superior LC and PFS without providing a survival benefit in early and intermediate stage HCC. Additional larger prospective randomized controlled trials should be conducted to further investigate differences in clinical outcomes amongst patients with more advanced disease.

537 Background: A+B is the preferred first-line (1L) standard of care for uHCC, with emerging RW evidence supporting its use in a broad patient (pt) cohort. We evaluated pt characteristics, clinical and treatment outcomes in pts treated at five U.S. institutions: Mayo Clinic, Houston Methodist, Moffitt Cancer Center, Mays Cancer Center, and University of Arizona. Methods: This is a retrospective study of uHCC pts who initiated A+B after January 1, 2019. De-identified pt data were extracted by treating oncologists. Overall survival (OS) and real-world progression-free survival (rwPFS) were assessed using Kaplan-Meier methods for all pts and for a “trial-like” subgroup with characteristics similar to those in the IMbrave150 trial (ECOG performance status [PS] 0-1, Child-Pugh [CP] class A, albumin-bilirubin [ALBI] grade 1-2). HCC-related hospitalizations were evaluated within 1 year of A+B initiation. Results: A total of 300 eligible pts were treated with 1L A+B (median age 68 years, 79% male, 79% White, 82% BCLC C, 44% viral etiology,12% ECOG PS >1). Liver function was CP A in 73% (36% A5, 31% A6, 6% not reported), CP B in 26% pts (15% B7, 7% B8, 5% B9), and CP C in 2 (<1%) pts. Compared with CP A, more CP B pts had characteristics of compromised liver function (CP A vs B: cirrhosis: 61% vs 91%; ascites: 7% vs 46%; encephalopathy: 4% vs 17%; esophageal varices: 14% vs 32%), bile duct invasion (2% vs 11%), and ECOG PS>1 (8% vs 22%), all Ps<0.001. Over a median follow-up of 8.7 mos, 244 (81%) pts discontinued A+B, primarily due to disease progression. Toxicity-related treatment discontinuation and hospitalizations due to treatment-related adverse events (TRAE) were similar between the two groups (Table). Median OS (mOS) was 14.4 mos (95% CI: 12.3, 18.2) and median rwPFS was 6.8 mos (95% CI: 5.8, 8.4). In the trial-like subgroup (n=194), mOS was 19.5 mos (95%CI: 14.6, 24.7) and median rwPFS was 8.8 mos (95% CI: 7.6, 12.1). In the CP B subgroup, mOS was 5.6 mos (95% CI: 4.6, 11.3) and median rwPFS was 3.1 mos (95% CI: 2.4, 5.8). Conclusions: This study demonstrates the RW outcomes of 1L A+B in a diverse pt cohort. Results from the “trial-like” pts further confirm the reproducible efficacy of A+B in clinical practice. Although pts with CP-B had higher hospitalization rates due to disease progression or symptoms, consistent with their underlying liver complications, they had similar rates of toxicity-related treatment discontinuation and TRAE-related hospitalizations compared to CP-A. Further characterization of safety for A+B in CP B pts within a prospective, controlled trial is warranted. N (%) CP A (n=219) CP B (n=79) Treatment discontinuation* 167 (76) 75 (95) Atezolizumab-related toxicity 20 (12) 13 (17) Bevacizumab-related toxicity 26 (16) 16 (21) Hospitalization* 87 (40) 58 (73) Symptom-related 42 (48) 35 (60) Progression 8 (9) 11 (19) TRAE 7 (8) 6 (10) *P-value comparing CP A vs CP B <0.001.

Abstract Background: PARP inhibitor (PARPi) monotherapy has previously demonstrated clinical activity only in patients with a germline BRCA mutation (BRCAmut), while single-agent anti-programmed cell death protein 1 (PD-1) therapy has achieved response rates of only 5–20% in advanced triple negative breast cancer (TNBC). In preclinical studies, PARP inhibition enhanced anti-tumor immunity, increased infiltration of proliferating CD8+ T cells, and synergized with anti-PD-1 agents in BRCA wildtype (wt) tumors. TOPACIO is a fully enrolled, phase I/II trial of niraparib + pembrolizumab (pembro) in advanced TNBC. This combination achieved 28% objective response rate (ORR) and 50% disease control rate (DCR) in evaluable patients. Although activity was highest in patients with BRCAmut (ORR=60%; DCR=80%), durable clinical benefit was also observed in patients without BRCA mutations. In this study, we conducted exploratory biomarker analyses to evaluate their potential correlation with durable clinical benefit (any complete response [CR] or partial response [PR] regardless of duration or stable disease [SD] for ≥16 weeks) beyond BRCA mutations. Method: ORR was assessed by RECIST v1.1. Duration of disease control (DDC) was defined as time from first dose of study treatment to radiologic disease progression or death. Tumor mutational status of homologous recombination repair (HRR) and other DNA damage repair (DDR) pathway genes was determined using an NGS panel. Immunoprofiling was conducted using NanoString IO360 panel complimented with 30 DNA repair spike-ins. Tumor immune micro-environment was characterized using multiplex immuno-fluorescence (CycIF). PD-L1 status was determined using the Agilent/DAKO 22C3 IHC clinical trial assay. Results: Of 46 evaluable patients, 20 achieved durable clinical benefit (any CR/PR or SD≥16 weeks) with niraparib + pembro combination, of which 8 were tumor BRCA wild type (wt), and 1 was BRCA unknown. Of the 9 BRCAwt/unknown patients, 5 had deleterious mutations in HRR/DDR pathway genes, whereas the remaining 4 had no mutations (HRR/DDR wt). Mutations that were associated with response include CHEK1 (CR; DDC=10.3 mos), ATR (CR; DDC=6.4 mos), PALB2 (PR; DDC=3.5 mos), BLM (SD; DDC=8.1 mos), and NBN/RAD51C (SD; DDC=3.7 mos). Of 4 patients that had no identified mutations (HRR/DDR wt), 1 patient had CR; DDC=10.3 mos, and the remaining 3 patients had SD with DDC ranging from ∼4-8 mos. Of note, all 4 HRR/DDR wt patients were also PD-L1-negative. Table:Durable clinical benefit in BRCAwt/unknown patientsHRR/DRR MutationsPD-L1 StatusBest ResponseDDC (Months)CHEK1+CR10.3†ATR+CR6.4PALB2*UnknownPR3.5BLM-SD8.1NBN/RAD51C+SD3.7None-CR10.3†None-SD8.2None-SD4.2None-SD3.9*BRCA status unknown; †Treatment is ongoing. Conclusion: Patients with mutations beyond BRCA achieved durable clinical benefit with niraparib + pembro treatment; five of these patients had DDC &gt;6 mos. Mutations in genes that are associated with the HRR/DDR pathway appear to confer sensitivity to niraparib + anti-PD1. Additional translational analyses, including immunoprofiling and CycIF, will be presented. Funding: TESARO, Inc., Waltham, MA, USA sponsored the study. Citation Format: Vinayak S, Tolaney SM, Schwartzberg L, Mita M, McCann G, Tan AR, Wahner Hendrickson A, Forero A, Anders C, Wulf G, Dillon P, Lynce F, Zarwan C, Erban J, Färkkilä A, Zhou Y, Buerstatte N, Graham JR, Arora S, Dezube B, Telli ML. Durability of clinical benefit with niraparib + pembrolizumab in patients with advanced triple-negative breast cancer beyond BRCA: (TOPACIO/Keynote-162) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD5-02.