Citations

Abstract Background: High-dose interleukin-2 (IL-2) is administered after tumor-infiltrating lymphocyte (TIL) infusion to promote in-vivo expansion and persistence, yet optimal dosing and the clinical significance of out-of-specification (OOS) TIL products remain unclear. We investigated the impact of number of infused IL-2 doses and manufacturing OOS status on outcomes in metastatic melanoma treated with commercial TIL therapy. Methods: We retrospectively analyzed 31 patients treated across three Mayo Clinic sites. Planned IL-2 was 600,000 IU/kg every 12 hours for ≤6 doses; actual dosing varied based on clinical tolerance. Patients were grouped as low (0-2) vs high (≥3) IL-2 doses. TIL products were classified as within-specification or OOS per commercial release criteria. Survival associations were evaluated using Kaplan-Meier and multivariable Cox regression. Results: In our 31-patient cohort, the median age was 59 years (range 17-77), 58% were male, and 84% had ECOG 0. At TIL infusion, M-stage distribution was M1a 6%, M1b 10%, M1c 61%, and M1d 23%. LDH was elevated above the upper limit of normal in 42%. The median number of IL-2 infusions was 4 (range 0-6); 58% of patients received ≥3 doses, while 2 patients (6%) received none. Out-of-specification (OOS) TIL products occurred in 6 patients (19%). Best responses included complete response (26%) and partial response (23%), for an overall response rate of 48% and a disease-control rate of 61% (CR + PR + SD). Among responders, the median duration of response was 84 days (95% CI 73-95). At data cutoff, the median follow-up was 253 days (95% CI 137-370). The most common grade 3/4 toxicities occurring >14 days after TIL infusion were lymphopenia (39%), anemia (16%), and thrombocytopenia (10%). Median progression-free survival (PFS) was 99 days (95% CI 73-125) with 20 progression events, and median overall survival (OS) was 193 days (95% CI 32-354) with 13 deaths. Number of infused IL-2 doses was dependent on patients tolerability. Receiving ≥3 IL-2 doses was associated with improved overall survival (394 vs 101 days; p < 0.001) and a trend toward longer progression-free survival (110 vs 59 days; p = 0.055). OOS products predicted inferior PFS (30 vs 110 days; p = 0.003) and showed a trend toward worse OS (120 vs 394 days; p = 0.079). In multivariate analysis, ≥3 IL-2 doses independently improved PFS (HR 0.20, 95% CI 0.06-0.69; p = 0.011) and OS (HR 0.09, 0.02-0.36; p = 0.001), while OOS status increased risk of progression (HR 8.10, 2.24-29.25; p = 0.001) and death (HR 6.16, 1.35-28.20; p = 0.019). Conclusions: Higher number of infused doses IL-2 and meeting commercial TIL release criteria were independently associated with improved outcomes. Citation Format: Mohamed A. Aboelatta, Jeffrey E. Johnson, Jabra G. Zarka, Matyáš Benada, James W. Jakub, Roxana S. Dronca, Ruqin Chen, Mahesh Seetharam, Deepti Behl, Svetomir N. Markovic, Lisa A. Kottschade, Heather N. Montane, Matthew S. Block, Anastasios Dimou, Robert R. McWilliams, Paula Gill, Yi Lin, Arkadiusz Z. Dudek. Impact of number of IL-2 infusions and product out of specification status on outcomes of tumor infiltrating lymphocyte therapy for melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3706.

Abstract Background: Up to 50% of patients with breast cancer experience chemotherapy-inducednausea (CIN) and 95% experience fatigue. A comprehensive understanding of biological mechanisms remains elusive. Herein, we evaluated the association of CIN and fatigue with clinical and multi-omics features, including serum and stool metabolites before (T1) to after chemotherapy (T2). Methods: Patients with breast cancer (n=36) who were to receive chemotherapy, provided symptom assessment using the Memorial Symptom Assessment Scale, stool and blood samples at T1 and T2. Patients provided dietary intake data using a Dietary Screener Questionnaire at T1. Descriptive and univariate analyses evaluated associations of co-occurringsymptoms and diet with CIN and fatigue at T2. Gut microbiome was sequenced using shotgun metagenomics. Targeted metabolomics was performed on stool and serum. Shift in the abundance of taxonomic groups and metabolite levels from T1 to T2 were evaluated in association with CIN and fatigue. Results: Approximately 64% of the patients experienced CIN and 94% experienced fatigue atT2. Three gastrointestinal symptoms co-occurred with CIN and fatigue. Higher daily average intake of calcium (p=0.013) and dairy (p=0.035) were associated with CIN. Levels of hexosylceramides, ceramide, phosphatidylcholine and sphingomyelins were significantly perturbed in association with CIN and fatigue (p<0.05). Conclusion: CIN and fatigue are associated with perturbation in the sphingolipid turnover pathway, which negatively impacts functions in the gut-liver axis that include apoptosis activity and change in bile acid levels. Confirmatory studies are warranted to support the development of interventions to alleviate CIN and fatigue in patients with breast cancer receiving chemotherapy.Keywords: breast cancer; chemotherapy-induced nausea; fatigue; metabolites; sphingolipids Citation Format: Komal Preet Singh, Brenda J. Ernst, Jun Chen, Surendra Dasari, Felipe Batalini, Cindy Tofthagen, Kathryn J. Ruddy, Keenan Pituch, Linda Chlan. Perturbations in gut liver axis functions are associated with chemotherapy induced nausea and fatigue in patients with breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6309.

Abstract Background: Colorectal cancer (CRC) remains a leading cause of cancer-associated mortality and is difficult to treat due to therapy resistance and limited durable responses. Esophageal cancer (EC) is similarly challenging, exhibiting highly aggressive and metastatic behavior that contribute to its poor prognosis. Adoptive TCR-engineered T cell (TCR-T) therapies show promise in these settings, but their efficacy is limited by suboptimal antigen specificity and an immunosuppressive tumor microenvironment (TME). To address these barriers, we isolated high-affinity TCRs from a phage-displayed TCR library targeting KRASG12V neoantigen in CRC and CTAG1B cancer/testis antigen (CTA) in EC. Methods: KRASG12V(8-16)/HLA-A11:01-restricted and CTAG1B(157-165)/HLA-A02:01-restricted TCRs were isolated from an optimized phage-displayed TCR library generated from healthy donor CD8+ T cells through high-throughput biopanning. Binders were screened against antigen-family peptides and irrelevant controls by phage ELISA to eliminate cross-reactivity. Binding affinities were measured by SPR. Antigen-specific TCRs (asTCRs) were cloned into lentiviral vectors and transduced into primary human T cells. TCR-T function was assessed using peptide-pulsed T2 cells and KRASG12V+ or CTAG1B+ tumor cells through LDH-release cytotoxicity and cytokine secretion assays. Normal human cells were used to evaluate off-target toxicity. In vivo antitumor activity was tested in NOD/SCID-IL2rγ-/- xenografts with histological confirmation of TCR-T infiltration. Results: Next-generation sequencing confirmed that the 109-scale library contained >90% functional genes and >80% sequence diversity. Three high-affinity TCRs were identified for each antigen (KD as low as 1.07 μM). These TCRs exhibited strict antigen specificity with no detectable cross-reactivity. TCR-T cells expressing asTCRs showed potent antigen-dependent cytotoxicity against KRASG12V+/HLA-A11:01+ colorectal and CTAG1B+/HLA-A02:01+ esophageal tumor cells (up to 80% lysis, p<0.01), accompanied by robust IFN-γ and TNF-α secretion (>1000 pg/mL, p<0.01). No killing was observed against any of seven healthy cell types. TCR-T cells remained effective at low effector-to-target ratios and maintained stable proliferation and effector-memory phenotypes. In xenograft models, KRAS- and CTAG1B-targeted TCR-T cells induced significant tumor regression compared to unmodified T cell controls (p<0.05), with increased effector TCR-T infiltration, and reduced antigen escape. Conclusions: This work establishes a rapid and robust platform for isolating potent, safe, antigen-specific TCRs targeting both oncogenic driver mutation (KRASG12V) and an immunogenic CTA (CTAG1B). TCR-T cells demonstrated strong antitumor activity in vitro and in vivo, supporting the translational potential of this approach for solid tumor treatment. Citation Format: Obed Boadi Amissah, Wenfang Chen, Zhiyuan Li, Gloria Bora Kim. KRASG12V- and CTAG1B-targeted TCR-T cells from phage TCR library suppress colorectal and esophageal tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5618.

Abstract Background: Hepatocellular carcinoma (HCC) is largely refractory to immune checkpoint blockade due to immune exclusion, stromal barriers, and aberrant vasculature. We evaluated whether multimodal therapy - external beam radiotherapy (EBRT) for antigen release, intratumoral dendritic cell (DC) vaccination for antigen presentation, PD-L1 blockade for immune activation, and VEGF inhibition for vascular normalization - could convert “cold” HCC tumors into sustained immune-inflamed states. Methods: Serial biopsies (baseline, post-EBRT, end-of-treatment [EOT], and progression [PD] when available) from three patients enrolled in an ongoing phase II trial (NCT03942328) underwent multiplex immunofluorescence, spatial neighborhood analysis, and transcriptomic profiling. Longitudinal changes in cellular composition, immune-stromal architecture, spatial contact networks, and pathway activity were compared. Results: Baseline tumor microenvironments (TMEs) were strongly immune-excluded, dominated by tumor (PanCK+60-70%) and stroma (SMA+/Vimentin+25-30%) with sparse immune infiltration (<10-15%). Post-therapy, immune complexity and spatial connectivity increased 2-3-fold in all patients. Patient 1 showed robust cold-to-hot conversion with CD8+(3x), CD4+(2.2x), and DC (2.3x) expansion, increased CD8-DC interactions (2.5x), and reduced tumor fraction (-40%). Transcriptomics showed marked upregulation of IFN-γ (↑3.4x), HLA-DRA (↑2.7x), and reductions in VEGFR2 (↓50%) and HIF1A (↓40%), consistent with vascular normalization. Patient 2 exhibited stromal/vascular remodeling and improved T-cell infiltration but restricted immune diversity, with CD4+/CD8+ dyads (↑2.2x) and B/NK cells(↓ 60%). Neighborhood diversity rose (3→7 communities) and immune-tumor proximity improved (distance ↓ 35%). Patient 3 showed transient inflaming with CD8+(↑3x), DC(↑2x), and new CD4-CD20/CD4-CD56 interactions, followed by relapse marked by stromal/myeloid re-expansion (SMA+↑1.8x, CD14+↑2.5x), angiogenic resurgence (VEGFR2/CD34+↑2.2x), contraction of immune networks, and genomic shift from activating CTNNB1 mutation loss to ATM gain. DCs accumulated but localized mainly to DC-DC or DC-myeloid niches, indicating non-productive antigen presentation. Conclusions: Multimodal EBRT+DC+PD-L1/VEGF blockade induces four-sided synergistic TME reprogramming - antigen release, immune priming, checkpoint release, and vascular normalization - promoting cold-to-hot conversion in HCC. Durable inflaming correlates with sustained T-cell/DC expansion and vascular remodeling, whereas relapse reflects stromal/myeloid reinforcement and genomic adaptation. These findings define mechanistic trajectories of TME remodeling and highlight actionable barriers to sustained immunotherapy response in HCC. Citation Format: Lionel Aurelien Kankeu Fonkoua, Christopher L. Hallemeier, Basim Salem, Arina Tkachuk, Kaitlynn McCay, Panwen Wang, Ying Li, Thomas D. Atwell, Krishan R. Jethwa, Caitlin Conboy, Nguyen H. Tran, Leslie A. Washburn, Melody Wu, Chen Wu, Andre De Menezes Silva Corraes, Rondell P. Graham, Jose Caetano Villasboas, Kevin Regan, Zuoyi Shao, Rayaan Kamal, Nathan R. Foster, Haidong Dong, Sean Park, Yi Lin, Lewis R. Roberts. Multimodal immunotherapy remodels the tumor microenvironment in hepatocellular carcinoma: Integrative spatial and transcriptomic profiling from a Phase II trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 7935.

Abstract Background: Cellular immunotherapy has transformed cancer treatment, but success in solid tumors remains limited by long manufacturing times, high costs, and the need for viral vectors that permanently modify DNA. To address this, we examined electroporation (EP) and mechanoporation (MP) approach to transfect T cells with mRNA to enable the development of a bedside immune cell editing platform. NKG7, natural killer cell granule-7, was previously demonstrated to play key function in activating T-cell cytotoxicity function. mRNA transfection of T cells with NKG-7 can increase these cells’ anti-tumor cell killing. We examine EP and MP methods for NKG7 transfection in primary peripheral blood mononuclear cells (PBMCs) from healthy donors. Method: Synthetic Clean Cap mRNAs encoding NKG7 or NKG7 with membrane-bound cRNA IL-2 were introduced into PBMCs by electroporation (MaxCyte) or mechanoporation (Portal Bio). T cell expression of NKG7 and IL-2 were analyzed by CytoFlex flow and Kaluza. Result: The yield at EP and MP were comparable at 0.615+/-0.09% and 0.597+/-0.16%, respectively. Viability were high at above 80% for 3 days after EP and MP. NKG7 and NKG7+cIL-2 mRNA transfection led to different NKG7 expression kinetics in T-cells and between EP and MP. With EP, CD4 T-cells showed an increase in NKG7 expressions with the highest MFI ratio (NKG7 MFI/ IgG MFI) compared to mock EP at Day 1 for the NKG7 -only EP (1.25 ± 0.38) and at Day 2 for NKG7+cIL-2 EP (1.20 ± 0.27). CD8+ T cells displayed a similar trend, with peak NKG7 expression at Day 1 for NKG7 EP (1.22 ± 0.76) and Day 2 for NKG7+cIL-2 EP (1.21 ± 0.90). However, MP did not enhance NKG7 expression in CD4+ T cells. NKG7 expression peaked at Day 1 for both NKG7 (1.28 ± 0.42) and NKG7 + cIL-2 (1.24 ± 0.20). IL2 expression peaked at Day 1 for both EP and MP: EP, CD4+ T (91.5% ± 4.4), CD8+ T (92.7% ± 12.8); MP, CD4+ T (88.9% ± 31.7), CD8+ T (84.7% ± 9.6). Functional assays for anti-tumor cell killing of these transfected cells are currently ongoing. Conclusions: We report that EP of PBMC can transfect all cell populations. MP may yield comparable yield, viability and NKG7 expression in CD8 T cells compared to EP, but without the need to isolate CD8 T cells from PBMC. EP and MP method can be used for bedside immune cell transfection depending on the target and cell populations of interest. Citation Format: Chen Wu, Christoph Schaefers, Malvika Gupta, Kevin Regan, Zuoyi Shao, Andre De Menezes Silva Corraes, Virginia Van Keulen, Jacob Hirdler, Tobias Peikert, Timothy D. Wiltshire, Haidong Dong, Yi Lin. A non-viral mRNA engineering platform for rapid, same-day immune-cell therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5198.

Abstract Background: Patients (pts) with myeloma (MM) receiving CAR-T therapy have usually been exposed to many prior therapies. Melphalan (HDM) and other chemotherapies can induce cellular senescence. It has recently been shown that MM cells can also exhibit features of therapy-induced senescence (TIS). TIS tumor cells are associated with resistance to therapy and relapse. To investigate the presence of TIS MM cells prior to CAR-T and association with response, we examined the transcriptome and phenotype of MM prior to CAR-T. Method: We used scRNA-seq data from bone marrow (BM) MM cells: Boiarsky, et al. (GSE193531, dbGaP: phs001323.v3.p1) newly diagnosed MM (NDMM) pts; Dhodapkar, et al. (GSE210079), pre- and post CAR-T; pts who received CAR-T at Mayo Clinic, pre- (N=10) and post- (N=2). To evaluate TIS, single-cell gene set enrichment analysis (scGSEA) for several gene sets (PMID: 40164720): SenUp (Senescence Upregulated), SenGA (Senescence Growth Arrest), and SCAPs (Senescent Cell Anti-apoptosis Pathways); and a Plasma Cell Senescence (PCSen) gene set (GSE5900, GSE47552). To assess TIS and myeloid phenotype, BM MM cells (CD138+) were stained for CD14, CD16, KLRG1 and GPNMB and analyzed by CytoFlex and Kaluza. Results: In the integrated dataset, scGSEA showed significantly higher enrichment of PCSen, SenUp, SenGA, and SCAPs in late-stage MM cells (both pre- and post-CAR-T) compared to NDMM and healthy donors (p<0.05, Kruskal-Wallis with Dunn’s posttest). Conversely, the Normal gene set was significantly enriched in healthy plasma cells relative to MM (p<0.05). Expression of CDKN2A, which encodes the senescence marker p16, was also increased in late-stage MM relative to NDMM or healthy plasma cells. Notably, in our newly generated scRNA-seq samples collected within 6 months before CAR-T, a significant inverse correlation between senescence marker expression and progression free survival (PFS) post-CAR-T was seen, suggesting that MM cells exhibiting TIS may be more resistant to T cell mediated cytotoxicity. We found that 62.5% (25/40) of pts had >1% MM cells that were CD14+. Among them, the median CD14+ MM cells were 5.5% (1-71%); and median CD14+CD16+ MM cells were 2.14% (0.4-67%). Among 7 pts with available samples for KLRG1 and GPNMB assessment, 100% (7/7) had KLRG+ MM cells (median: 59% (24-99%)) and 57% (4/7) had GPNMB+ MM cells (median: 15% (3.9-30%)), and KLRG1+GPNMB+ MM cells (median: 9.6% (3.8-17%)). Conclusion: Our study shows that late-line MM cells exhibit transcriptional and phenotype profiles consistent with TIS. This senescent phenotype may contribute to resistance to immunotherapies, including CAR-T. Additional phenotype data is collected and will be presented. A phase II clinical trial is ongoing (NCT06940297) to assess for the combined treatment with senolytic drugs dasatinib and quercetin peri-CART to deepen clinical response. Citation Format: Sofia Arbelaez, Andre De Menezes Silva Corraes, Gabriel Alvares Borges, Chen Wu, Christoph Schaefers, Malvika Gupta, Zuoyi Shao, Kevin Regan, Rayaan Kamal, Angelo Jose Guilatco, Neal I. Sannuli, Ying Li, Taxiarchis Kourelis, Wilson Gonsalves, Moritz Binder, Melinda Tan, Nadine Abdallah, Megan Weivoda, Yi Lin. Myeloma cells with therapy-induced senescence-like phenotype are associated with resistance to CAR-T therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6467.

Abstract Background: Therapy-induced senescence (TIS), a tumor cell state associated with distinct gene expression patterns and implicated in therapy resistance, may be activated in Multiple Myeloma (MM) patients (pt) by genotoxic chemotherapies, such as high-dose melphalan (HDM). We investigated whether TIS is activated in MM cells following chemotherapy and linked to resistance to T-cell directed therapies. Method: We integrated scRNA-seq data from healthy donors (CNTRL) and MM pts (newly-diagnosed (NDMM), pre/post-CAR-T) bone marrow plasma cells (PCs) using two public datasets (Boiarsky, et al.; Dhodapkar, et al.) and a newly generated pt dataset. Senescence was evaluated using scGSEA with published gene sets (SenUp, SenGA, and SCAPs). For in vitro MM cytotoxicity assay, human H929 MM cells were treated with vehicle (Veh) or HDM (3µM, IC90) for 6h and examined for TIS features. H929VEH or H929HDM were co-cultured with CNTRL T cells with or without teclistamab (Tec, 10 nM) or with day 14 PBMCs from MM pts post-CAR-T (E:T 5:1). CAR+ T cells were high among the day 14 PBMC (median±SD: 93.4±7.2% of CD3+ cells, n=6). Results: scGSEA revealed significantly higher enrichment of SenUp, SenGA, and SCAPs in late-stage MM cells compared to NDMM and CNTRL (p<0.05). Expression of CDKN2A, encoding the senescence marker p16, was also increased in late-stage MM relative to NDMM/CNTRL PCs. Of interest, cells enriched for senescence also exhibited enrichment for myeloid markers (TET2, CEBP family). Notably, in pre-CAR-T, increased baseline senescence or myeloid marker expression showed an inverse association with CAR-T progression-free survival (PFS), suggesting TIS confers resistance to T cell mediated cytotoxicity. This may be due to myeloid plasticity. TIS MM cells generated in vitro, H929HDM, exhibited a distinct morphology characterized by increased cell size and enhanced cytoplasmic granularity. Increased CD14 expression was seen in 4 of the 6 experiments (median, range % increase: 11.2%, 2.5%-21%), consistent with myeloid plasticity; Increased KLRG1 expression was seen in 5 of the 7 experiments (median MFI ratio, range: 3.7, 1.3-471). No significant change was seen in GPNMB expression. Compared to H929VEH, H929HDM had a reduction in killing by CAR-T cells (median±SD: 22.8±32.94% n=6, p=0.016, Wilcoxon paired test). Similarly, H929HDM had a 10.69% decrease in Tec-mediated T-cell killing compared to H929VEH (n=8, p=0.02, Wilcoxon paired test). Conclusions: Late-stage MM cells exhibit transcriptional signatures consistent with TIS, which can be associated with decreased PFS to CAR-T. We report an in vitro model of TIS MM cells for testing of resistance to T cell killing. Based on these findings, a phase II trial (NCT06940297) is underway to test the hypothesis that peri-CAR-T senolytic therapy with dasatinib and quercetin will deepen responses by targeting this resistant TIS MM population. Citation Format: Christoph Schaefers, Angelo Jose Guilatco, Sofia Arbelaez, Gabriel Alvares Borges, Chen Wu, Andre de Menezes Silva Corraes, Malvika Gupta, Zuoyi Shao, Kevin Regan, Rayaan Kamal, Neal I. Sannuli, Ying Li, Taxiarchis Kourelis, Wilson Gonsalves, Melinda Tan, Nadine Abdallah, Yi Lin, Megan Weivoda. Myeloma cells with therapy-induced senescence-like phenotype have increased resistance to killing by T cell directed therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6475.

Abstract Introduction: Liver cancer remains a leading cause of cancer mortality globally with limited treatment options for patients (pts) with unresectable hepatocellular carcinoma [HCC] and intrahepatic cholangiocarcinoma [iCCA][1,2,3,4]. We hypothesize that combining the intratumoral dendritic cell (DC) vaccination after external beam radiotherapy (EBRT) without (phase I) and with (phase II) systemic atezolizumab and bevacizumab (atezo/bev for HCC) would enhance tumor-specific immunity and improve clinical outcomes, and present preliminary results from our phase I/II trial (NCT03942328). Methods: Peripheral blood mononuclear cells (PBMCs) were collected at baseline (PRE), after radiation (EBRT), and after completion of DC without or with atezo/bev (POST). Single-cell RNA sequencing with TCR sequencing were analyzed using CellRanger v7.0.1, Immunopipe, Seurat v5.3.0, & Gene-set enrichment analysis (GSEA). Long EFS (EFS-L) is defined as >=12 months (mo) for phase I and >=18mo for phase II, and short EFS (EFS-S) below that. Results: Seventeen patients have been analyzed to date (Phase I: n=8 [4 HCC, 4 iCCA]; Phase II: n=9 HCC). 674,106 cells were sequenced (146,843 PRE; 168,838 EBRT; 114,437 POST). GSEA for EFS-L vs EFS-S were comparable at PRE, EBRT and POST between phase I and phase II. EFS-S was associated with enrichment of interferon alpha (IFNα; B naïve, monocytes, pDC, cDC2, NK, Treg, CD8 Tcm and Tem at PRE and POST; B intermediate, CD4 Tem and NK at EBRT) and reactive oxygen species (ROS; PRE: pDC, CD8 Tcm, Tem. EBRT: CD4 Tem. POST: CD8 T naïve Tem, CD4 Tcm & Tem, cDC2) pathways. In contrast, EFS-L was associated with enrichment of WNT-β-catenin (WNT; CD14 mono at EBRT & POST, B intermediate at EBRT), TGFb (PRE: NK; EBRT: B intermed, CD4 Tem; POST: monocytes, CD4 naïve & Tem, pDC, cDC2), and angiogenesis (EBRT: NK; POST: monocytes, cDC2) pathways. Interestingly, enrichment of protein secretion pathway in NK cells was associated with EFS-L, but among other cells were associated with EFS-S (PRE: CD16 mono, Treg; POST: CD16 mono, CD4 & D8 Tem). Compared to phase I, addition of atezo/bev in phase II pts was associated with a significant increase in Gini coefficient (p<0.0001), suggesting expansion of certain TCR clones, along with a trend for increased Gini coefficient from Pre to Post in both phase I and II. Conclusions: Preliminary analysis of this study combining EBRT with intratumoral DC vaccination +/- PD-L1/VEGF blockade identified distinct treatment-related changes in systemic cellular immune profiles. Enhanced TCR clonal diversity in phase II suggests added immunologic benefit from PD-L1/VEGF blockade. As accrual continues, integrated analyses will identify systemic immune correlates of clinical benefit and resistance to this multimodal immunotherapy approach. Citation Format: Melody Wu, Panwen Wang, Chen Wu, Ying Li, Christopher L. Hallemeier, Thomas D. Atwell, Nguyen H. Tran, Andre de Menezes Silva Corraes, Kevin Regan, Zuoyi Shao, Rayaan Kamal, Haidong Dong, Lewis R. Roberts, Sean Park, Yi Lin, Lionel Aurelien Kankeu Fonkoua. Radiation-dendritic cell combination therapy drives systemic cellular immune shifts in liver cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 3741.

Abstract Background: Epidemiologic and other studies have identified environmental, occupational, and genetic risk factors for lymphoid and myeloid malignancies, but most studies have been conducted in Western populations. Investigations in populations with differing exposure patterns, distributions of disease subtypes, and genetic architecture are needed to fully understand hematopoietic tumor etiology. Methods: We conducted a large, multicenter, hospital-based case-control study of lymphoid and myeloid neoplasms in East Asia (AsiaLymph), including 5,671 lymphoid cases, 1,879 myeloid cases, and 3,858 controls. Participants completed a computer-assisted personal interview and provided biospecimens. Cases underwent central pathology review and were coded into the WHO Classification. Herein, we describe the study methods in detail and report association results for education, body mass index, and family history. Results: Greater BMI at age 20 but not at age 40 was associated with odds of total lymphoid neoplasm (per 5 kg/m2 increase: OR [95% CI]: 1.18 [1.09-1.27]), total myeloid neoplasm (OR [95% CI]: 1.17 [1.05-1.29]), and several subtypes. Greater educational attainment was associated with increased odds of total lymphoid neoplasm (for college vs. less than primary education: OR [95% CI]: 1.41 [1.21-1.65]) but not myeloid neoplasm (OR [95% CI]: 1.17 [0.95-1.45]; p-heterogeneity=0.02). There were also positive associations between family history of hematologic cancer in first degree relatives and odds of lymphoid neoplasm (OR [95% CI]: 1.53 [1.15-2.03]) and myeloid neoplasm (OR [95% CI]: 1.65 [1.11-2.44]) and specific subtypes. None of the evaluated risk factors were associated with NK/T-cell lymphoma, which supports a distinct etiology for this subtype. Conclusion: The AsiaLymph Study is one of the largest molecular epidemiology studies of both lymphoid and myeloid neoplasms with standardized World Health Organization classification of histopathologic subtypes and will serve as a valuable resource for etiologic investigations into risk factors for these malignancies. Citation Format: Qing Lan, Lauren M. Hurwitz, John K. Chan, Tai Hing Lam, Kexin Chen, Yok Lam Kwong, Xu Caigang, Brian CH Chiu, Raymond Liang, Ip Dennis, Wei Hu, Bryan Bassig, Mark Purdue, Jun Xu, Sarah Locke, Sophia S. Wang, James R. Cerhan, Sonja Berndt, Jonathan N. Hofmann, Jianxin Shi, Kai Yu, Shahinaz Gadalla, Lisa J. McReynolds, Rena Jones, Hongji Dai, Zhangyan Lyu, Lugui Qiu, Wei Liu, Huilai Zhang, Xianhuo Wang, Lindsay M. Morton, Stephen Chanock, Martha Linet, Melissa C. Friesen, Roel Vermeulen, Nathaniel Rothman. A multi-center hospital-based case-control study of lymphoid and myeloid neoplasms (AsiaLymph): Study design and initial findings for education, body mass index, and family history [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5051.

Abstract Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma. Previous studies have shown that DLBCL cells are susceptible to GPX4 (Glutathione peroxidase 4)-regulated ferroptosis, an iron-dependent type of programmed cell death characterized by increased reactive oxygen species and excessive lipid peroxidation. In addition to GPX4, FSP1 (Ferroptosis suppressor protein 1, previously known as AIFM2) is a glutathione-independent repressor of ferroptosis that has shown prognostic significance in solid tumors. In this study, we aimed to reveal the significance of GPX4 and FSP1 in DLBCL. Patients and Methods: We performed immunohistochemistry (IHC) for GPX4 and FSP1 in a large cohorts of patients with de novo DLBCL, and evaluated their cytoplasmic and nuclear expression. Prognostic analysis was performed for FSP1 and GPX4 expression in patients treated with rituximab (R)-CHOP or CHOP chemotherapy, respective of TP53 mutation status, as p53 regulates ferroptosis and TP53 mutation is associated with poorer prognosis in DLBCL. Results: FSP1 expression with a ≥10% cutoff was positive in 42.3% of DLBCL cases. Patients with TP53 mutations had a non-significant trend of higher mean FSP1 expression than those with wild-type (Wt) TP53 (P=0.11). Prognostic analysis revealed that cytoplasmic FSP1+ expression was associated with significantly poorer overall survival and progression-free survival in Wt-TP53 DLBCLs treated with R-CHOP (P=0.016 and P=0.003, respectively), and only showed non-significant unfavorable trends in TP53 mutated DLBCLs and patients treated with CHOP. In contrast, GPX4 expression did not show a significant unfavorable prognostic effect in DLBCL, and in fact, was associated with a non-significant trend of better survival. Previously we have quantified immune cell abundance and PD-1/PD-L1 expression in the tumor microenvironment of the study cohort using multiplex fluorescent IHC. Correlative analysis found that FSP1+ patients had significantly higher mean and median abundance of CD68+ cells (both M1 and M2 macrophages) and CD11c+ cells than FSP1- patients. Further analysis in Wt-TP53 and mutated TP53 subcohorts found that only in the TP53 mutated DLBCL subcohort, FSP1 expression was associated with significantly higher mean and median CD163-CD68+ (M1) and overall CD68+ macrophages, whereas in the Wt-TP53 DLBCL subcohort, FSP1 expression was associated with significantly higher median (but not mean) CD163+CD68+ (M2) macrophages and CD11c+ cells. Summary: Cytoplasmic FSP1 expression but not GPX4 had significantly adverse prognostic effect in patients with Wt-TP53 DLBCL treated with standard immunochemotherapy. Our results also suggest that in addition to ferroptosis regulation, macrophage abundance was relevant for the prognostic effects of FSP1 expression. Citation Format: Beibei Lyu, Zijun Xu-Monette, Xiaoxian X. Zhao, Eric D. Hsi, Ming Chen, Carlo Visco, Alexandar Tzankov, Karen Dybkaer, Mu-En Wang, Chang Wang, Qingyan Au, Harry Nunns, Zenggang Pan, Benjamin Parsons, Santiago Montes-Moreno, Fenghuang Zhan, Michael B. Møller, Leon Bernal-Mizrachi, Youli Zu, Shanxiang Zhang, Weina Chen, Govind Bhagat, Yong Li, KEN H. YOUNG. Expression of the ferroptosis suppressor FSP1 but not GPX4 shows significant adverse prognostic effect in diffuse large B-cell lymphoma with wild-type TP53 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4661.