Citations

Abstract ZC3H18 is a multifunctional regulator of gene expression that is lost in a subset of high-grade serous ovarian cancers (HGSOC). Our prior studies have established that the loss of ZC3H18 diminishes BRCA1 levels, leading to the disruption of homologous recombination DNA repair (HR) and heightened sensitivity of HGSOC cells to PARP inhibitors. Here we show an additional facet to ZC3H18's impact, showing that its loss also induces a reprogramming of energy metabolism in HGSOC. Our findings demonstrate that the depletion of ZC3H18 results in reduced mRNA and protein levels of the NAD+-biosynthetic enzyme, NMNAT1, in HGSOC cells. Mechanistic studies uncovered that ZC3H18 occupies the NMNAT1 promoter, facilitating NMNAT1 transcription by recruiting CDK12 onto the promoter. Consistent with this mechanism, loss of ZC3H18 led to a reduction in CDK12 levels on the NMNAT1 promoter, diminishing NMNAT1 abundance and subsequently causing a decline in cellular NAD levels. These observations unveil a previously unknown role for ZC3H18 in HGSOC, shedding light on its involvement in the regulation of energy metabolism. Importantly, our findings provide valuable insights into potential therapeutic pathways that leverage the metabolic changes linked to ZC3H18 deficiency. Citation Format: Benjamin Wilson, Natalie Wilson, Xianfeng Chen, Shuwen Zhang, Chen Wang, Larry M. Karnitz, Scott H. Kaufmann, Arun Kanakkanthara. ZC3H18: A novel regulator of NAD+ metabolism in high-grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4447.

Abstract Introduction: Chimeric antigen receptor T-cell (CAR-T) therapy is an established treatment modality for the management of refractory and/or relapsed non-Hodgkin lymphoma (NHL). Despite restrictions on granulocyte colony-stimulating factor (G-CSF) use in registration clinical trials due to potential worsening of cytokine release syndrome (CRS), G-CSF is often prescribed for neutrophil recovery post-CAR-T in clinical practice. We conducted a retrospective study to assess the association between G-CSF use and the safety and efficacy of CAR-T. Methods: Following Institutional Review Board approval, we retrospectively analyzed NHL patients receiving commercial CD19-targeted CAR-T across Mayo Clinic sites (Arizona, Florida, and Minnesota) between October 2017 and May 2023. Demographics, labs, and post CAR-T events were collected. Electronic medical records were reviewed for G-CSF exposure within Day 1 - 100 post-CAR T. Differences by G-CSF status were examined using a Chi-square test and Kruskal Wallis tests. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival (OS) were calculated using Cox model. Results: Among 270 CAR-T patients; 106 received G-CSF within 30 days and 164 did not. Median age was 56.9 with G-CSF and 58.3 without G-CSF. Most were male (75.2% G-CSF, 62.6% no G-CSF). Diffuse large B cell lymphoma was the predominant NHL subtype (67.0% G-CSF, 65.2% no G-CSF). G-CSF within 30 days was not associated with reduced incidence of neutropenic fever (11.7% G-CSF vs 9.9% no G-CSF, p = 0.6593) or documented infection (22.1% vs 18.3%, p = 0.4439). G-CSF correlated with decreased profound neutropenia duration (ANC < 100 μL, 0 vs 2 days, p < 0.0001) and incidence within 30 days ( 31.7% vs 60.4%, p < 0.0001) as well as incidence of protracted profound neutropenia (> 7 days, 3.8% vs 22.8%, p < 0.0001). G-CSF was associated with a higher incidence of cytopenias between days 30 -100: severe neutropenia (ANC < 500/uL, 28.8% vs 15.2%, p = 0.0075), severe anemia (Hb < 8 g/dL, 21% vs 9.7%, p = 0.0114), and severe thrombocytopenia (Plt < 50 g/L, 35.2% vs 20.9%, p = 0.0099). Logistic regression analysis showed that none of the examined covariates, including prior autologous stem cell transplant, ECOG PS score, and receipt of bridging therapy, were associated with severe neutropenia likelihood. G-CSF was associated with a higher CRS incidence (89.6% vs 79.9%, p = 0.0343), but grade 3 CRS or higher (4.7% vs 3.7%, p = 0.6675) was no different. No difference in complete response rates (66% vs 61.1%, p = 0.4707) or 2-year OS (p = 0.523) was observed between the 2 groups. Conclusion: G-CSF within 30 days was associated with reduced duration and incidence of profound neutropenia without a significant impact on incidence of neutropenic fever or documented infections. There was a signal of association between G-CSF and increased incidence of low-grade CRS and delayed cytopenias (day 30-100) that warrants confirmation in larger studies. Citation Format: Lay She Ng, Claire I. Yee, Radhika Bansal, Mohamed A. Kharfan-Dabaja, Grzegorz S. Nowakowski, Allison C. Rosenthal, Javier Munoz, Januario Castro, Wern Lynn Ng, Hemant S. Murthy, Yi Lin, Matthew R. Buras, Madiha Iqbal, Yucai Wang, Talal Hilal. Impact of G-CSF on safety and efficacy of CAR T-cell therapy in non-Hodgkin lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6327.

Abstract Background: Neoadjuvant immunotherapy (IO) has become standard of care for early-stage triple negative breast cancer (TNBC). I-SPY2 was the first randomized trial to examine the efficacy of IO therapy in high-risk HR+HER2- breast cancer, where most IO arms showed improved efficacy relative to control. We also previously showed immune-gene expression signatures associate with pathologic complete response (pCR) in HR+HER2- treated with IO; and developed a clinically applicable Immune classifier (ImPrint) predicting response to IO that is now being used in I-SPY2.2 as part of the Response Predictive Subtypes. Here we report the performance of ImPrint in HR+HER2- patients from 5 IO arms. Methods: 204 HR+HER2- (MammaPrint high risk) patients from 5 IO arms (anti-PD1, anti-PDL1/PARPi, anti-PD1/TLR9 dual-IO, and anti-PD1 +/- LAG3 dual-IO) and 191 patients from the control arm were included in this analysis. Patients were classified ImPrint+ (likely sensitive) vs. ImPrint- (likely resistant), by Agendia, Inc, using pre-treatment mRNA. Performance of ImPrint for predicting pCR to IO was characterized and compared to that of MammaPrint (ultra) High2 risk (MP2) and tumor grade (III). Based on the DRFS of pCR vs. non-pCR HR+HER2-/ImPrint+ patients (median follow up ~4.5yr), we predicted the DRFS in the IO vs. control arms using an exponential model as a function of the pCR rates. Results: Overall, the pCR rate over the 5 IO arms was 33%. 28% of HR+HER2- patients were ImPrint+; and pCR rates with IO were 76% in ImPrint+ vs. 16% in ImPrint-, with the highest pCR rate >90% in a dual-IO arm. In the control arm, pCR rates were 33% in ImPrint+ and 8% in ImPrint-. Based on the pCR rates in the IO vs. control (76% vs. 33%), the predicted DRFS of HR+HER2-/ImPrint+ patients are 91% vs 80% at 5 years, respectively. This translates to a risk reduction of 52% for the IO arm relative to standard chemotherapy in HR+HER2-/ImPrint+ patients. We also compared MP2 and tumor grade (III) to ImPrint+ as pCR predictors, as these markers have been used or proposed as selection markers for neoadjuvant IO trials in HR+HER2-. The pCR rates for MP2, Grade III, at 56%, 45%, respectively, are much smaller than that for ImPrint+ at 75% pCR; thus ImPrint appears to be a more precise predictive biomarker for neoadjuvant IO therapy in the HR+HER2- breast cancers. Conclusion: These results suggest that a subset of high risk HR+HER2- breast cancers is highly sensitive to immunotherapy, and by using a specific and sensitive selection strategy patients could achieve pCR rates similar to what is seen with best neoadjuvant therapies in TNBC and HER2+ (i.e., pCR rate > 65-70%). ImPrint, an FDA IDE-enabled assay currently being further evaluated in I-SPY2, may represent the way to identify patients for IO that best balances likely benefit vs risk of serious immune-related adverse events. Citation Format: Denise M. Wolf, Christina Yau, Lajos Pusztai, Rita Nanda, Jo Chien, Erica Stringer-Reasor, Rebecca Shatsky, Claudine Isaacs, MInetta Liu, Hyo Han, Hatem Soliman, Michael Campbell, Annuska Glas, Andrei Barcaru, Lorenza Mittempergher, Midas Kuilman, Lamorna Brown Swigart, Gillian Hirst, Hongmei Yu, Philip Beineke, Amrita Basu, I-SPY2 Investigators, Douglas Yee, W. Fraser Symmans, Angela DeMichele, Jane Perlmutter, Amy Delson, Laura Huppert, Hope Rugo, Amy Clark, Nola Hylton, Paula Pohlmann, Laura Esserman, Laura van 't Veer. Immune subtyping identifies a subset of HR+HER2- early-stage breast cancer patients with a very high likelihood of response to neoadjuvant immunotherapy (IO): Results from 5 IO arms of the I-SPY2 TRIAL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1207.

Abstract Background: Immune checkpoint inhibitors (ICIs) have significantly improved outcomes for patients with metastatic non-small cell lung cancer (NSCLC). However, clinical management is challenging. The PD-L1 biomarker does not optimally guide the choice between ICI monotherapy and combination ICI-chemotherapy, and there are currently no biomarkers to predict immune-related adverse events (irAEs). Here, we describe a versatile platform based on plasma proteomics and machine learning for generating predictive tools to support treatment decisions. Methods: Pre-treatment plasma samples were collected from 616 NSCLC patients receiving ICI-based therapy (NCT04056247). Clinical benefit (CB) data and irAEs were recorded. Proteomic profiling of plasma samples was performed using the SomaScan® assay, covering ~7000 proteins per sample. Proteins associated with Clinical Benefit (progression-free survival at 12 months) were classified as resistance-associated proteins (RAPs). Proteins associated with grade ≥3 irAEs occurring within the first 100 days of treatment were classified as toxicity-associated proteins (TAPs). RAPs and TAPs were integrated into two separate machine learning-based models, yielding CB and irAE probabilities, respectively. The CB model used a CB probability threshold to assign patients a PROphet-positive or PROphet-negative result. Bioinformatic analysis was performed on RAPs and TAPs. Results: CB and irAE models displayed strong predictive performance with a high correlation between predicted probability and observed CB or irAE rate (CB model: R2=0.98; p-value<0.0001; irAE model: R2= 0.92; p-value <0.0001). In the CB model, patients classified as PROphet-positive achieved significantly longer overall survival (OS) than PROphet-negative patients, with a median OS of 25.9 vs. 10.8 months (hazard ratio, HR = 0.51; p-value<0.001). Furthermore, patients with PD-L1 ≥50% tumors and a PROphet-negative result had significantly longer OS with ICI-chemotherapy in comparison to ICI monotherapy (HR=0.23, p-value = 0.0003), suggesting that combination therapy is preferable for such patients despite high PD-L1 levels. Bioinformatic analysis showed that RAPs related to immune regulation, angiogenesis, chemo-resistance, and other potential resistance mechanisms displayed higher expression levels in patients who did not benefit from treatment. Neutrophil- and inflammation-related proteins were significantly enriched in patients who experienced irAEs. Conclusions: We describe two machine-learning based predictive tools that may be used separately or in combination to inform treatment decisions based on the patient’s likelihood to benefit from ICI therapy and to develop serious irAEs. Our findings also provide biological insights related to treatment resistance and immune-related toxicity. Citation Format: Michal Harel, Petros Christopoulos, Igor Puzanov, Jair Bar, Iris Kamer, Niels Reinmuth, Ina Koch, Mor Moskovitz, Adva Levy-Barda, Alona Zer, Michal Lotem, David Farrugia, Rivka Katzenelson, Gillian Price, Abed Agbarya, Helen Cheley, Adam Hassani, Mahmoud Abu-Amna, Tom Geldart, Anirban Chatterjee, Andreas Polychronis, Maya Gottfried, Yanyan Lou, Tatiana Harkovsky, Alison Brewster, Ido Wolf, Ella Tepper, Ben Yellin, Itamar Sela, Coren Lahav, Yehonatan Elon, Raya Leibowitz, Adam P. Dicker, Young Kwang Chae, Ryan J. Sullivan, David Carbone, David Gandara, Jarushka Naidoo. Plasma proteomics-based models for predicting therapeutic benefit and immune-related adverse events in non-small cell lung cancer patients treated with immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1208.

Abstract Background: The point of prostate cancer (CaP) diagnosis (PPCD) instantly leads to a life changing experience for Black men, with diverse emotional reactions that includes fear, denial, overwhelmingness, cancer fatalism etc. Black men diagnosed with CaP expressed several needs at the PPCD, including time to reflect on the diagnosis, being comfortable, emotional support, psycho-oncology support and social determinants of health (SDOH) navigation. Given that Black men are diverse in terms of their needs at the PPCD, precision intervention is needed to support them. Aim: The aim was to develop, implement, and establish the acceptance and usability of a Virtual Reality Assistant (ViRA) that will provide precision intervention tailored to the needs of Black men at the PPCD. This study is one of the five iCCaRE for Black Men projects focused on survivorship care. Methodology: The development of the ViRA was guided by CaP survivors through qualitative study. Reflective, analytic, and interpretive memos were used to generate action plans for the development of the ViRA. Based on a comprehensive PPCD ViRA intervention guide created by the team, the ViRA prototype was developed with mobile immersive technologies that integrated SDOH navigation, standard CaP psycho-oncology support and emotional support. The goal was to have the intervention personalized to everyone based on participant-provided information. Alpha testing of the ViRA is ongoing and will be completed on November 20, 2023. Participants are three prostate cancer survivors and three clinicians. The assessments will confirm the accuracy of the ViRA predictions and the functionality of the ViRA. Results: We developed the ViRA SDOH screening and navigation tool to identify participants’ needs and appropriately connect them with relevant support services and resources in their communities. The emotional support intervention was based on four CaP survivors as virtual reality avatars, providing empathetic rapport through self-disclosure and sharing of survivorship stories in different settings (home, clinic, barbershop etc). The psycho-oncology support intervention was developed with the guidance of a psycho-oncologist, with her avatar providing psychoeducation about the PPCD experience, reify and concretize the PPCD experience, and foster hope using the basic tenets of Problem-Solving Therapy. The results of the alpha testing and the modified ViRA will be presented during the conference. Conclusion: Meeting the needs of Black men at the PPCD requires a personalized and decentralized approach, which would allow Black men to access support anywhere. The presentation will unveil the iCCaRE ViRA, a smart and connected personalized AR-enabled intervention that will deliver SDOH navigation, CaP psycho-oncology support and emotional support tailored to the needs of Black men. Citation Format: Folakemi T. Odedina, Che Ngufor, Arnold Merriweather, Deidre Pereira, Roxana Dronca, Ernest Kaninjing, Kimlin Ashing, Solomon Rotimi, Vinessa Gordon, iCCaRE for Black Men Consortium. Connecting Black men to point of prostate cancer diagnosis (PPCD) support using precision intervention based on Virtual Reality Assistant (ViRA) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2230.

Abstract Despite the remarkable efficacy of chimeric antigen receptor T -cell therapy (CART) for the treatment of B-cell malignancies, durable remission remains limited often due to tumor relapse. We have previously demonstrated that tumor-derived extracellular vesicles (EVs) induced CART cell failure in preclinical models. To characterize the impact of tumor EV induced CART cell dysfunction, we assessed microRNA (miRNA) profiles contained within tumor EVs from two independent patient cohorts and studied how they contributed to CART dysfunction. Our first cohort included patients with chronic lymphocytic leukemia (n=50). We previously showed that CLL patient derived EVs induce a state of CART cell dysfunction. To understand this dysfunction, we interrogated the miRNA cargo significantly enriched in CLL EVs and how their coculture impacts CART signaling by RNAseq. Here, we found a significant enrichment in miR-125a within CLL EVs as compared to healthy donor controls (p=.0001). CART cocultured with CLL EVs showed alterations in T cell activation pathways, where miR-125a targets TNFAIP3 and NFkB pathways were activated. These findings implicate miR-125a from CLL EVs in CART dysfunction. Next, we aimed to validate the impact of miRNA on CART cell outcomes in the clinic. We interrogated miRNA profiles from patients with diffuse large B cell lymphoma (DLBCL) treated with CART cell therapy (CART19-28ζ, axicabtagene ciloleucel). EV miRNA cargo was compared between responders (complete remission at 6 months, n=10) and non-responders (no response 1 month post CART19, n=10) to identify differentially enriched miRNAs across groups. miR-125a was again significantly upregulated in EVs of non-responders as compared to responders to CART19 treatment (fold change=3.28, padj=.018). To study the direct effect of miR-125a on CART cell functions, we generated and studied the effector functions of CART19-28z following transfection with miR-125a or negative miR control. CART19 cells transfected with miR-125a showed a dose dependent decrease in killing of lymphoma cells as compared to miR-control (p=.0001). miR-125a also significantly increased the rate of apoptosis in CART19 cells (fold change=1.95, p=.024) and decreased the level of CART proliferation (fold change=.71, p=.013) as compared to controls. Notably, miR-125a did not impact tumor cell growth, further verifying a direct CART effect. In summary, our studies demonstrate the impact of tumor derived miRNAs on CART cell outcomes. They identify that miR-125a is 1) associated with CLL EV induced CART dysfunction, 2) significantly elevated in non-responders to CART therapy in the clinic, and 3) able to decrease CART19 efficacy through reduced CART killing/proliferation and increased apoptosis. These results highlight a novel mechanism of CART19 failure induced through miRNA cargo delivery by tumor-derived EVs and the role of miR-125a in inducing CART19 dysfunction. Citation Format: Olivia Sirpilla, R. Leo Sakemura, Ismail Can, Truc N. Huynh, James H. GIrsch, Claudia Manriquez Roman, Carli M. Stewart, Kun Yun, Ekene J. Ogbodo, Long Mai, Omar Gutierrez Ruiz, Makena Rodriguez, Brooke Kimball, Hong Xia, Jose C. Villasboas, Stephen Ansell, Nora Bennani, Patrick B. Johnston, Jonas Paludo, Januario Castro, Mohamed Kharfandabaja, Sameer Parikh, Neil Kay, Yi Lin, Elizabeth Siegler, Saad Kenderian. Tumor-derived microRNA125a induces CART cell apoptosis and failure in B cell malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3841.

Abstract Introduction: Despite the remarkable activity of CD19-directed chimeric antigen receptor T cell therapy (CART19), durable remissions remain low, especially in chronic lymphocytic leukemia (CLL). Ibrutinib is an oral irreversible inhibitor of Bruton’s tyrosine kinase and is a first line therapy for CLL. Preclinical and early clinical data indicate that ibrutinib plus CART19 may be synergistic through inhibition of IL2-inducible T cell kinase. To systematically study the effects of prior ibrutinib treatment on subsequent CART functions, we utilized blood samples from the pivotal clinical trial E1912 (NCT02048813). E1912 was a phase 3 randomized trial comparing treatment with ibrutinib/rituximab (IR) to fludarabine/cyclophosphamide/rituximab (FCR) in previously untreated patients with CLL, which led to the FDA approval of ibrutinib as a first-line therapy in CLL. Methods: We evaluated the ex vivo expansion and effector functions of T cells and CART19 generated from patients (n=12) with CLL progression following treatment with IR or FCR. We generated CART19 from longitudinal samples obtained at baseline (pretreatment), 6 months post-treatment, 12 months post-treatment, and disease progression. Isolated T cells were lentivirally transduced to express CD28- or 41BB-costimulated CAR19. To assess antigen specific killing and proliferation, untransduced T cells or CART19 were co-cultured at a 1:1 ratio with the CD19+ cell line, JeKo-1, as a surrogate for CLL cells. Results: Ex vivo T cell expansion increased from an average of 1.5-fold at baseline to 6.7-fold at 6 months, 11.6-fold at 12 months, and 16.9-fold at progression, following ibrutinib-based therapy (p = 0.02, 0.04, and 0.04, respectively). Improved T cell expansion was independent of disease burden (p = 0.89, 0.73, and 0.54 for expansion vs B cell count at 6 months, 12 months, and progression). T cell expansion significantly worsened following treatment with FCR-based therapy compared to ibrutinib-based therapy (0.6- vs 11.6-fold at 12 months and 0.9- vs 16.9-fold at progression; p = 0.031 and 0.039, respectively). Starting at 6 months post-IR, CART19 demonstrated improved antitumor activity and antigen-specific proliferation against JeKo-1. There was no significant difference in the expansion of 41BB- vs CD28-costimulated CART19 following ibrutinib treatment. However, 41BB-CART19 showed enhanced antigen-specific proliferation upon stimulation with JeKo-1 (p = 0.008, 0.02, and 0.02 at 6 months, 12 months, and progression). Conclusion: Our results indicate significant improvement in T cell expansion and CART19 cell functions in patients with CLL following frontline ibrutinib-based therapy, and worsening T cell functions after FCR treatment. Improvement in T cell functions is independent of malignant B cell eradication and is more significant in 41BB-costimulated CART19. Citation Format: Truc Ngoc Huynh, Victoria Wang, Tait Shanafelt, Elizabeth L. Siegler, Carli M. Stewart, Kun Yun, Long K. Mai, Olivia Sirpilla, James H. Girsch, Claudia Manriquez-Roman, Jennifer M. Feigin, Makena Rodriguez, Brooke L. Kimball, Hong Xia, Reona L. Sakemura, Ismail Can, Omar L. Gutierrez-Ruiz, Ekene J. Ogbodo, Erin E. Tapper, Lionel A. Fonkoua, Mehrdad T. Hefazi, Michael W. Ruff, Sameer Parikh, Neil E. Kay, Saad J. Kenderian. Frontline ibrutinib-based therapy enhances CART cell functions in patients with CLL: Analysis of the phase 3 randomized clinical trial ECOG-ACRIN E1912 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3849.

Abstract Background: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. In sub-Saharan Africa, HCC is the second most common cancer in men and the sixth in women. African patients present with HCC at a young age and at advanced stage of disease. Improved surveillance can increase early HCC detection. The GALAD score has good sensitivity in the diagnosis of HCC in Asia, Europe and North America, however, it has not been validated in an African cohort. The aim of this study was to assess the performance of the GALAD score in the diagnosis of HCC in Ghanaian patients. Methods: Clinical data from patients with cirrhosis (n=93) or HCC (n=78) from out-patient hepatology clinics at 3 teaching hospitals in Ghana were abstracted, and serum samples analyzed. A logistic regression model predicting HCC status based on GALAD score was constructed to obtain the Receiver Operating Characteristics (ROC) curve for GALAD. The area under the curve (AUC) with 95% confidence interval was calculated and used to assess the performance of the GALAD score in surveillance for HCC. Results: The median AFP (5010.2 vs. 3.4), L3% (28.3 vs. 0.3) and DCP (507.6 vs. 0.2) levels were all significantly higher among HCC cases than the controls (p<0.0001). The median GALAD score was also higher among HCC patients (8.0 vs. -4.1, p<0.0001). The AUC of the GALAD score in the diagnosis of HCC was 0.86 (95% CI 0.79 - 0.92). At a cut-off value of -0.37, the GALAD score had a sensitivity of 0.81 and a specificity of 0.86. In a re-fit of the logistic regression model, the most significant factors in the GALAD model in our cohort were AFP-L3% and log(DCP). The AUC of the new GALAD model after model selection was 0.89. Conclusion: The GALAD score can be used to detect HCC in Ghana and has the potential to improve HCC surveillance in low-resource settings in sub-Saharan Africa. Citation Format: Yvonne Ayerki Nartey, Ju Dong Yang, Tyler Zemla, Joshua Ayawin, Shadrack Osei Asibey, Mohamed El-Kassas, Sally Afua Bampoh, Amoako Duah, Adwoa Agyei-Nkansah, Yaw Asante Awuku, Mary Yeboah Afihene, Hiroyuki Yamada, Jun Yin, Amelie Plymoth, Lewis Rowland Roberts. Accuracy of the GALAD serologic model in the diagnosis of hepatocellular carcinoma in Ghanaian patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4802.

Abstract Background: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of patients with deficient DNA mismatch repair (d-MMR) cancers, yet less than half of patients with metastatic colorectal cancer (mCRC) receive clinical benefit. We analyzed heterogeneity within d-MMR tumors using a multi-omics approach inclusive of percent unstable microsatellite loci (MS). Methods: We studied consecutive patients with d-MMR mCRC with available primary tumors (N=32) that were treated with an anti-PD-1 antibody at Mayo Clinic (2015-2022). Tumors were profiled using a whole exome and transcriptome platform (ImmunoID NeXT®). MSIsensor was used to calculate percent unstable microsatellite loci from whole exome sequencing data. CIBERSORT and ssGSEA were used to analyze immune gene expression in relationship to percent unstable microsatellite loci. An immune checkpoint gene expression signature was calculated as the mean expression of CD274, CTLA-4, HAVCR2, LAG-3, PDCD1, PDCD1LG2, TIGIT. Aforementioned variables were analyzed in relationship to objective tumor response (RECIST version 1.1). A Cox proportional hazards model was fit to predict progression-free survival (PFS). Results: Among 32 patients with d-MMR mCRC treated with PD-1 blockade, 16 (50%) received first-line anti-PD-1 therapy; others had > 1 prior chemotherapy regimen. Eighteen (56.3%) tumors harbored BRAFV600E, 4 (12.5%) had mutant KRAS, and median PFS was 24.6 months (95% CI: 8.4, NR) with 18 events. Neither tumor mutation burden (TMB) nor PD-L1 mRNA expression predicted PFS. Median percent unstable MS loci was 14.38 (IQR: 2.6-23.2). Patients whose tumors had higher percent unstable MS loci had significantly better PFS (Q2-4 vs Q1; HR: 0.22, 95%CI: 0.06, 0.62; P=0.003), and were associated with increased objective response (P=0.049). Tumors with higher unstable loci also had higher neoantigen clonality (R= 0.64; P= 0.0003) and increased M0 (resting) macrophages (P=0.02). Nonresponders (vs responders) to PD-1 blockade had an increased immune checkpoint expression signature (P= 0.005). Conclusion: A higher percentage of unstable microsatellite loci, associated with higher neoantigen clonality and resting macrophages, was predictive of anti-PD-1 efficacy. Furthermore, an immune checkpoint gene expression signature was associated with objective response. Citation Format: Bahar Saberzadeh-Ardestani, Oluwadunni E. Emiloju, Rondell P. Graham, Jason T. Lewis, Charles W. Abbott, Sean M. Boyle, Frank A. Sinicrope. Prediction of PD-1 treatment outcome in mismatch repair deficient metastatic colorectal cancer using a multi-omic approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 578.

Abstract Therapeutic inhibition of BCR signaling using Bruton tyrosine kinase inhibitors (BTKis) has remarkable efficacy in the treatment of chronic lymphocytic leukemia (CLL). However, the efficacy of BTKis is limited by the development of drug resistance, which can be mediated through mutations in genes encoding proteins of BCR signaling pathways. Approaches targeting the BCR mutant proteins have been limited by the large heterogeneity of these mutations. In addition, BCR signaling mutations are only detected in up to two-thirds of the CLL patients who progressed with BTKi treatment, suggesting mechanisms beyond genetic mutations. We previously showed that the BCR signaling pathway impacts the chromatin landscapes of CLL B cells (Wang et al., Blood Cancer J. 2022), suggesting that epigenetic mechanisms are exploited by CLL B cells to support their survival. To gain insights into the epigenetic regulation of BTKi treatment in CLL B cells, we analyzed the genome-wide chromatin accessibility (ATAC-seq) and histone modification (H3K4me1, H3K4me3, H3K27ac, H3K27me3) profiles (CUT&Tag) of leukemic cells from 4 CLL patients on BTKi ibrutinib treatment in a sequential fashion (i.e., baseline, on ibrutinib treatment, and at relapse). We also performed the same analysis in a CLL cohort at two stages of ibrutinib treatment (baseline and while on treatment, n=20). Our studies showed that suppressing BCR signaling by BTKi leads to the downregulation of genes associated with mitochondrial translation, a key process of mitochondrial biogenesis. We also found decreased chromatin accessibility and H3K27ac deposition at the promoters of these MT genes. Interestingly, in patients who experienced disease progression on ibrutinib, there was a restoration of MT gene expression, chromatin accessibility, and H3K27ac levels at the MT gene promoters similar to baseline samples, suggesting an epigenetic-regulated MT both in BTKi treatment naïve and relapsed CLL patients. Importantly, MT inhibition led to a decreased survival of primary CLL B cells. These findings point toward an epigenetic mechanism utilized by BCR signaling to promote MT and leukemic cell survival. We then observed that the transcription factor NRF1 is enriched at the MT promoter in CLL B cells. CRISPR-mediated depletion of NRF1 led to reduced mitochondrial translation and cell survival in BCR signaling active malignant B cell lines and primary CLL B cells. These results suggest that NRF1 controls an epigenetic program linking BCR signaling to control MT, which in turn supports BCR signaling-dependent CLL B cell survival. Our findings demonstrated that BCR signaling utilizes epigenetic mechanisms that regulate mitochondrial metabolism to enhance cell survival in both treatment naïve and BTKi-relapsed CLL. These findings may provide new therapeutic directions for untreated and BTKi-relapsed CLL patients. Citation Format: Olivia M. Depies, Sutapa Sinha, Sameer Parikh, Neil Kay, Zhiquan Wang. An epigenetic program that links oncogenic signaling to mitochondrial biogenesis supports leukemic cell survival in chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5842.