Transposon DNA sequences facilitate the tissue-specific gene transfer of circulating tumor DNA between human cells.

The exchange of genes between cells is known to play an important physiological and pathological role in many organisms. We show that circulating tumor DNA (ctDNA) facilitates cell-specific gene transfer between human cancer cells and explain part of the mechanisms behind this phenomenon. As ctDNA migrates into the nucleus, genetic information is transferred. Cell targeting and ctDNA integration require ERVL, SINE or LINE DNA sequences. Chemically manufactured AluSp and MER11C sequences replicated multiple myeloma (MM) ctDNA cell targeting and integration. Additionally, we found that ctDNA may alter the treatment response of MM and pancreatic cancer models. This study shows that retrotransposon DNA sequences promote cancer gene transfer. However, because cell-free DNA has been detected in physiological and other pathological conditions, our findings have a broader impact than just cancer. Furthermore, the discovery that transposon DNA sequences mediate tissue-specific targeting will open up a new avenue for the delivery of genes and therapies.

Nivolumab plus relatlimab in patients with previously treated microsatellite instability-high/mismatch repair-deficient metastatic colorectal cancer: the phase II CheckMate 142 study.

BACKGROUND: Programmed death-1 (PD-1) inhibitors, including nivolumab, have demonstrated long-term survival benefit in previously treated patients with microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) metastatic colorectal cancer (CRC). PD-1 and lymphocyte-activation gene 3 (LAG-3) are distinct immune checkpoints that are often co-expressed on tumor-infiltrating lymphocytes and contribute to tumor-mediated T-cell dysfunction. Relatlimab is a LAG-3 inhibitor that has demonstrated efficacy in combination with nivolumab in patients with melanoma. Here, we present the results from patients with MSI-H/dMMR metastatic CRC treated with nivolumab plus relatlimab in the CheckMate 142 study. METHODS: In this open-label, phase II study, previously treated patients with MSI-H/dMMR metastatic CRC received nivolumab 240 mg plus relatlimab 160 mg intravenously every 2 weeks. The primary end point was investigator-assessed objective response rate (ORR). RESULTS: A total of 50 previously treated patients received nivolumab plus relatlimab. With median follow-up of 47.4 (range 43.9-49.2) months, investigator-assessed ORR was 50% (95% CI 36% to 65%) and disease control rate was 70% (95% CI 55% to 82%). The median time to response per investigator was 2.8 (range 1.3-33.1) months, and median duration of response was 42.7 (range 2.8-47.0+) months. The median progression-free survival per investigator was 27.5 (95% CI 5.3 to 43.7) months with a progression-free survival rate at 3 years of 38%, and median overall survival was not reached (95% CI 17.2 months to not estimable), with a 56% overall survival rate at 3 years. The most common any-grade treatment-related adverse events (TRAEs) were diarrhea (24%), asthenia (16%), and hypothyroidism (12%). Grade 3 or 4 TRAEs were reported in 14% of patients, and TRAEs of any grade leading to discontinuation were observed in 8% of patients. No treatment-related deaths were reported. CONCLUSIONS: Nivolumab plus relatlimab provided durable clinical benefit and was well tolerated in previously treated patients with MSI-H/dMMR metastatic CRC. TRIAL REGISTRATION NUMBER: NCT02060188.

A Case Series of Choroidal and Orbital Neuroendocrine Tumors: Metastasis: Two Patients Treated With Peptide Radionuclide Therapy.

ABSTRACT: Neuroendocrine tumors (NETs) are rare cancers with heterogeneous histologies, response to treatments, and prognoses. Majority of these cancers originate in the gastrointestinal tract and metastasize to the liver. We report the cases of 5 patients with low-grade NET disease with rare metastases to the choroids. Two of the patients were treated with peptide receptor radionuclide therapy (lutetium 177 [ 177 Lu]). This is the first report confirming peptide radionuclide therapy safety in patients with low-grade NET with ocular metastases.

A Novel Pan-RAS Inhibitor with a Unique Mechanism of Action Blocks Tumor Growth in Mouse Models of GI Cancer.

Here, we describe a novel pan-RAS inhibitor, ADT-007, that potently inhibited the growth of RAS mutant cancer cells irrespective of the RAS mutation or isozyme. RAS WT cancer cells with activated RAS from upstream mutations were equally sensitive. Conversely, cells from normal tissues or RAS WT cancer cells harboring downstream BRAF mutations were insensitive. Insensitivity to ADT-007 was attributed to low activated RAS levels and metabolic deactivation by UDP-glucuronosyltransferases expressed in normal cells but repressed in RAS mutant cancer cells. Cellular, biochemical, and biophysical experiments show ADT-007 binds nucleotide-free RAS to block GTP activation of RAS and MAPK/AKT signaling. Local administration of ADT-007 strongly inhibited tumor growth in syngeneic immune-competent and xenogeneic immune-deficient mouse models of colorectal and pancreatic cancer while activating innate and adaptive immunity in the tumor immune microenvironment. Oral administration of ADT-007 prodrug inhibited tumor growth, supporting further development of this novel class of pan-RAS inhibitors for treating RAS-driven cancers. SIGNIFICANCE: ADT-007 is a 1 st -in-class pan-RAS inhibitor with ultra-high potency and unique selectivity for cancer cells with mutant or activated RAS capable of circumventing resistance and activating antitumor immunity. Further development of ADT-007 analogs or prodrugs with oral bioavailability as a generalizable monotherapy or combined with immunotherapy is warranted.

Deciphering cellular plasticity in pancreatic cancer for effective treatments.

Cellular plasticity and therapy resistance are critical features of pancreatic cancer, a highly aggressive and fatal disease. The pancreas, a vital organ that produces digestive enzymes and hormones, is often affected by two main types of cancer: the pre-dominant ductal adenocarcinoma and the less common neuroendocrine tumors. These cancers are difficult to treat due to their complex biology characterized by cellular plasticity leading to therapy resistance. Cellular plasticity refers to the capability of cancer cells to change and adapt to different microenvironments within the body which includes acinar-ductal metaplasia, epithelial to mesenchymal/epigenetic/metabolic plasticity, as well as stemness. This plasticity allows heterogeneity of cancer cells, metastasis, and evasion of host's immune system and develops resistance to radiation, chemotherapy, and targeted therapy. To overcome this resistance, extensive research is ongoing exploring the intrinsic and extrinsic factors through cellular reprogramming, chemosensitization, targeting metabolic, key survival pathways, etc. In this review, we discussed the mechanisms of cellular plasticity involving cellular adaptation and tumor microenvironment and provided a comprehensive understanding of its role in therapy resistance and ways to overcome it.

Advancing Inclusive Research (AIR) Site Alliance: Facilitating the inclusion of historically underrepresented people in oncology and ophthalmology clinical research.

BACKGROUND: The Advancing Inclusive Research (AIR) Site Alliance is composed of clinical research centers that partner with Genentech, a biotechnology company, to advance the representation of diverse patient populations in its oncology and ophthalmology clinical trials, test recruitment, and retention approaches and establish best practices to leverage across the industry to achieve health equity. METHODS: Through a data-driven selection process, Genentech identified 6 oncology and 3 ophthalmology partners that focus on reaching historically underrepresented patients in clinical trials and worked collaboratively to share knowledge and explore original ways of increasing clinical study access for every patient, including sites co-creation of a Protocol Entry Criteria Guideline with inclusion principles. RESULTS: For patients, three publicly available educational videos about clinical trials were created in multiple languages. The AIR Site Alliance has also defined invoiceable services for sites to enhance patient support; this has been built into the new study budget templates for sustainability. For healthcare professionals (HCPs), the first-of-its-kind AIR Educational Program was developed to focus on identifying and addressing bias and engaging historically underrepresented patient populations in trials. The sites also co-created videos for HCPs and patients on why advancing inclusive research matters. Over 16 regional health equity symposia have been delivered for patients, HCPs, and community leaders. CONCLUSIONS: This AIR Site Alliance is a model for other site alliances, including Kenya, South Africa, the United Kingdom, and Canada. Such alliances will build a robust and sustainable research ecosystem that includes diverse patient groups and encourages change across the healthcare system.

Advances in Immunotherapy for Hepatocellular Carcinoma (HCC).

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related deaths in the world. More than half of patients with HCC present with advanced stage, and highly active systemic therapies are crucial for improving outcomes. Immune checkpoint inhibitor (ICI)-based therapies have emerged as novel therapy options for advanced HCC. Only one third of patients achieve an objective response with ICI-based therapies due to primary resistance or acquired resistance. The liver tumor microenvironment is naturally immunosuppressive, and specific mutations in cell signaling pathways allow the tumor to evade the immune response. Next, gene sequencing of the tumor tissue or circulating tumor DNA may delineate resistance mechanisms to ICI-based therapy and provide a rationale for novel combination therapies. In this review, we discuss the results of key clinical trials that have led to approval of ICI-based therapy options in advanced HCC and summarize the ongoing clinical trials. We review resistance mechanisms to ICIs and discuss how immunotherapies may be optimized based on the emerging research of tumor biomarkers and genomic alterations.

Implementation of the Web-Enabled Cancer & Aging Resilience Evaluation (WeCARE) in an outpatient oncology setting.

INTRODUCTION: Although geriatric assessments (GAs) are recommended for use in older adults with cancer, their integration into oncology practice remain suboptimal. Here, we report our experience integrating web-enabled GA (WeCARE) into oncology practice as an augmented delivery method and provider interface format to overcome implementation barriers. MATERIALS AND METHODS: Older patients (≥60 years) with a gastro-intestinal (GI) malignancy presenting for an initial visit to medical oncology clinic at a single institution between December 7, 2021 and October 10, 2022 were contacted by staff two days in advance of their visits and sent a link to the WeCARE GA, rather than the paper version used previously. Results were directly embedded into the medical record. We describe our initial implementation outcomes and the results of a provider usability survey. RESULTS: Of 266 eligible patients, 221 (83.1%) were successfully contacted by telephone and 200 (75.2%) completed the WeCARE prior to their appointment. More than one phone call was required to make contact for 35.7% of patients, with a mean duration of phone conversation of 2.8 min. Most patients preferred email delivery to text (63% vs 31%); 4.5% were unable to access surveys due to inadequate technology, and 25.7% brought up additional logistical concerns. Among GI oncology providers surveyed, all six found the WeCARE tool and dashboard acceptable, appropriate, and feasible. However, only a third of providers often or always used the dashboard to inform treatment decisions and guide interventions. DISCUSSION: With nearly three-quarters of patients completing the WeCARE prior to their visits with minimal staff support and time required, this method of administration may be a viable format to overcome barriers to GA implementation. Additional work is needed to integrate the results meaningfully into clinical practice.

Phase II trial of nivolumab and metformin in patients with treatment-refractory microsatellite stable metastatic colorectal cancer.

BACKGROUND: Preclinical studies showed metformin reduces exhaustion of tumor-infiltrating lymphocytes and potentiates programmed cell death protein-1 (PD-1) blockade. We hypothesized that metformin with nivolumab would elicit potent antitumor and immune modulatory activity in metastatic microsatellite stable (MSS) colorectal cancer (CRC). We evaluated this hypothesis in a phase II study. METHODS: Nivolumab (480 mg) was administered intravenously every 4 weeks while metformin (1000 mg) was given orally, two times per day following a 14-day metformin only lead-in phase. Patients ≥18 years of age, with previously treated, stage IV MSS CRC, and Eastern Cooperative Oncology Group 0-1, having received no prior anti-PD-1 agent were eligible. The primary endpoint was overall response rate with secondary endpoints of overall survival (OS) and progression-free survival (PFS). Correlative studies using paired pretreatment/on-treatment biopsies and peripheral blood evaluated a series of immune biomarkers in the tumor microenvironment and systemic circulation using ChipCytometry and flow cytometry. RESULTS: A total of 24 patients were enrolled, 6 patients were replaced per protocol, 18 patients had evaluable disease. Of the 18 evaluable patients, 11/18 (61%) were women and the median age was 58 (IQR 50-67). Two patients had stable disease, but no patients had objective response, hence the study was stopped for futility. Median OS and PFS was 5.2 months (95% CI (3.2 to 11.7)) and 2.3 months (95% CI (1.7 to 2.3)). Most common grade 3/4 toxicities: Anemia (n=2), diarrhea (n=2), and fever (n=2). Metformin alone failed to increase the infiltration of T-cell subsets in the tumor, but combined metformin and nivolumab increased percentages of tumor-infiltrating leukocytes (p=0.031). Dual treatment also increased Tim3+ levels in patient tissues and decreased naïve CD8+T cells (p=0.0475). CONCLUSIONS: Nivolumab and metformin were well tolerated in patients with MSS CRC but had no evidence of efficacy. Correlative studies did not reveal an appreciable degree of immune modulation from metformin alone, but showed trends in tumorous T-cell infiltration as a result of dual metformin and PD-1 blockade despite progression in a majority of patients.

Management of neuroendocrine tumor liver metastases.

BACKGROUND: Neuroendocrine Tumors (NETs) are a group of tumors that arise from neuroendocrine cells, and are increasing in incidence worldwide. These tumors often metastasize to the liver, and management of these neuroendocrine tumor liver metastases (NELMs) requires a multi-disciplinary approach. We aim to provide a comprehensive update for treatment of NELMs. METHODS: We completed a comprehensive systemic review of papers involving the diagnosis, treatment, and outcomes of NELMs. We identified 1612 records via Scopus database literature search. Two independent authors reviewed these records, with 318 meeting criteria for inclusion in the final systemic review. RESULTS: Primary tumor resection with resection of liver metastases is the treatment of choice for patients with NELMs. Liver-directed therapies and liver transplantation can be considered for patients with unresectable liver metastases. Systemic medical therapy is used for managing tumor burden and symptoms caused by NELMs. CONCLUSIONS: Advancement in liver-directed and targeted systemic therapies provide improved options for patients with unresectable tumors. Given the complexity of NELMs, management of NELMs necessitates multidisciplinary teams at comprehensive health centers.

Anticancer Efficacy of KRASG12C Inhibitors Is Potentiated by PAK4 Inhibitor KPT9274 in Preclinical Models of KRASG12C-Mutant Pancreatic and Lung Cancers.

KRASG12C inhibitors, such as sotorasib and adagrasib, have revolutionized cancer treatment for patients with KRASG12C-mutant tumors. However, patients receiving these agents as monotherapy often develop drug resistance. To address this issue, we evaluated the combination of the PAK4 inhibitor KPT9274 and KRASG12C inhibitors in preclinical models of pancreatic ductal adenocarcinoma (PDAC) and non-small cell lung cancer (NSCLC). PAK4 is a hub molecule that links several major signaling pathways and is known for its tumorigenic role in mutant Ras-driven cancers. We found that cancer cells resistant to KRASG12C inhibitor were sensitive to KPT9274-induced growth inhibition. Furthermore, KPT9274 synergized with sotorasib and adagrasib to inhibit the growth of KRASG12C-mutant cancer cells and reduce their clonogenic potential. Mechanistically, this combination suppressed cell growth signaling and downregulated cell-cycle markers. In a PDAC cell line-derived xenograft (CDX) model, the combination of a suboptimal dose of KPT9274 with sotorasib significantly reduced the tumor burden (P= 0.002). Similarly, potent antitumor efficacy was observed in an NSCLC CDX model, in which KPT9274, given as maintenance therapy, prevented tumor relapse following the discontinuation of sotorasib treatment (P= 0.0001). Moreover, the combination of KPT9274 and sotorasib enhances survival. In conclusion, this is the first study to demonstrate that KRASG12C inhibitors can synergize with the PAK4 inhibitor KPT9274 and combining KRASG12C inhibitors with KPT9274 can lead to remarkably enhanced antitumor activity and survival benefits, providing a novel combination therapy for patients with cancer who do not respond or develop resistance to KRASG12C inhibitor treatment.

Association of emotional support with quality of life, mental health, and survival in older adults with gastrointestinal malignancies-Results from the CARE registry.

BACKGROUND: Emotional support (ES) is the most frequently reported support need among older adults with cancer. Yet, the association of ES with cancer outcomes is largely unknown. This study examined the association of ES with health-related quality of life (HRQoL), mental health, and survival among older adults with gastrointestinal (GI) malignancies. METHODS: We included newly diagnosed older adults (≥60 years) with GI cancer undergoing self-reported geriatric assessment at their first clinic visit. ES was measured using an adaptation of the Medical Outcomes Study (dichotomized adequate ES vs. inadequate ES). Outcomes included physical and mental HRQoL, anxiety, depression, and survival. Multivariable linear regression evaluated the association between ES and HRQoL scores. Multivariable logistic regression evaluated the association of ES with anxiety and depression. All models were adjusted for age at geriatric assessments, race, sex, and cancer type/stage. RESULTS: 795 participants were included. Median patient age was 68 years (IQR: 64-74), 58% were male, and most cancers were either colorectal (37.9%) or pancreatic (30.8%). Most (77.6%) had adequate ES. Patients with inadequate ES were more likely to be Black (31.5 vs. 20.8%, p = 0.005), disabled (24.1 vs. 10.4%, p < 0.001), widowed/divorced (54.2 vs. 24.8%, p < 0.001) and had lower physical and mental HRQoL t-scores (Physical ß: -3.35, 95% CI: -5.25, -1.46; Mental ß: -2.46, 95% CI: -4.11, -0.81) and higher odds of depression (aOR: 2.22, CI: 1.34-3.69). This study found no difference between those with adequate ES versus inadequate ES in the proportion of deaths within 1 year of diagnosis (24.3% vs. 24.2%, p = 0.966), or within 2 years of diagnosis (32.4% vs. 33.2%, p = 0.126). CONCLUSIONS: Older adults with inadequate ES have worse physical and mental HRQoL and higher odds of depression compared to those with adequate ES.

DNA-PK is activated by SIRT2 deacetylation to promote DNA double-strand break repair by non-homologous end joining.

DNA-dependent protein kinase (DNA-PK) plays a critical role in non-homologous end joining (NHEJ), the predominant pathway that repairs DNA double-strand breaks (DSB) in response to ionizing radiation (IR) to govern genome integrity. The interaction of the catalytic subunit of DNA-PK (DNA-PKcs) with the Ku70/Ku80 heterodimer on DSBs leads to DNA-PK activation; however, it is not known if upstream signaling events govern this activation. Here, we reveal a regulatory step governing DNA-PK activation by SIRT2 deacetylation, which facilitates DNA-PKcs localization to DSBs and interaction with Ku, thereby promoting DSB repair by NHEJ. SIRT2 deacetylase activity governs cellular resistance to DSB-inducing agents and promotes NHEJ. SIRT2 furthermore interacts with and deacetylates DNA-PKcs in response to IR. SIRT2 deacetylase activity facilitates DNA-PKcs interaction with Ku and localization to DSBs and promotes DNA-PK activation and phosphorylation of downstream NHEJ substrates. Moreover, targeting SIRT2 with AGK2, a SIRT2-specific inhibitor, augments the efficacy of IR in cancer cells and tumors. Our findings define a regulatory step for DNA-PK activation by SIRT2-mediated deacetylation, elucidating a critical upstream signaling event initiating the repair of DSBs by NHEJ. Furthermore, our data suggest that SIRT2 inhibition may be a promising rationale-driven therapeutic strategy for increasing the effectiveness of radiation therapy.

Targeting the metabolism and immune system in pancreatic ductal adenocarcinoma: Insights and future directions.

Pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), presents a challenging landscape due to its complex nature and the highly immunosuppressive tumor microenvironment (TME). This immunosuppression severely limits the effectiveness of immune-based therapies. Studies have revealed the critical role of immunometabolism in shaping the TME and influencing PDAC progression. Genetic alterations, lysosomal dysfunction, gut microbiome dysbiosis, and altered metabolic pathways have been shown to modulate immunometabolism in PDAC. These metabolic alterations can significantly impact immune cell functions, including T-cells, myeloid-derived suppressor cells (MDSCs), and macrophages, evading anti-tumor immunity. Advances in immunotherapy offer promising avenues for overcoming immunosuppressive TME and enhancing patient outcomes. This review highlights the challenges and opportunities for future research in this evolving field. By exploring the connections between immunometabolism, genetic alterations, and the microbiome in PDAC, it is possible to tailor novel approaches capable of improving immunotherapy outcomes and addressing the limitations posed by immunosuppressive TME. Ultimately, these insights may pave the way for improved treatment options and better outcomes for PDAC patients.

Survival and Prognostic Factors in Patients With Pancreatic Colloid Carcinoma Compared With Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: Colloid carcinoma (CC) is a rare subtype of pancreatic carcinoma. The aims of the study are to characterize the clinicopathological features and to evaluate the overall survival (OS) of patients with CC. METHODS: Patients diagnosed with pancreatic CC and pancreatic ductal adenocarcinoma (PDAC) between 2004 and 2016 were identified from the National Cancer Database using International Classification of Disease-O-3 morphology (8480/3 and 8140/3) and topography (C25) codes. Kaplan-Meier analysis and Cox proportional hazards models were used to analyze OS. RESULTS: Fifty-six thousand eight hundred forty-six patients were identified. A total of 2430 patients (4.3%) were diagnosed with pancreatic CC. Males constituted 52.8% of CC and 52.2% of PDAC. Colloid carcinoma presented with pathological stage I disease more often (16.7% vs 5.9%) and stage IV disease less often (42.1% vs 52.4%) than PDAC (P < 0.001). Stage I CC received chemotherapy (36.0% vs 59.4%) and neoadjuvant chemotherapy (4.4% vs 14.2%) less often compared with PDAC (P < 0.001). Statistically significant improved OS was seen among stage I, II, and IV CC compared with PDAC. CONCLUSIONS: Pancreatic CC presented as stage I disease more often compared with PDAC. Neoadjuvant chemotherapy was administered more often in stage I PDAC compared with CC. Colloid carcinoma had improved OS compared with PDAC among all stages except stage III.

Phase II randomised, double-blind study of mFOLFIRINOX plus ramucirumab versus mFOLFIRINOX plus placebo in advanced pancreatic cancer patients (HCRN GI14-198).

BACKGROUND: Vascular endothelial growth factor receptor (VEGFR)-mediated signalling contributes to andgiogenesis and therapy resistance in pancreatic ductal adenocarcinoma (PDAC). Ramucirumab (RAM) is a VEGFR2 monoclonal antibody. We conducted a randomised phase II trial to compare progression-free survival (PFS) between mFOLFIRINOX with or without RAM in first line therapy of metastatic PDAC. METHODS: This phase II randomised, multi-centre, placebo controlled, double-blinded, trial randomly assigned to recurrent/metastatic PDAC patients to either mFOLFIRINOX/RAM (Arm A) or mFOLFIRINOX/placebo (Arm B). The primary endpoint is PFS at 9 months, and the secondary endpoints include overall survival (OS), response rate and toxicity evaluation. RESULTS: A total of 86 subjects enrolled, 82 eligible (42 in Arm A versus 40 in Arm B). The mean age was comparable (61.7 versus 63.0, respectively). Majority were White (N = 69) and males (N = 43). The median PFS was 5.6 compared to 6.7 months, for Arm A and B, respectively. At 9 months, the PFS rates were 25.1% and 35.0% for Arms A and B, respectively (p = 0.322). The median OS in Arm A was 10.3 compared to 9.7 months for Arm B (p = 0.094). The disease response rate for Arm A was 17.7% compared to Arm B of 22.6%. FOLFIRINOX/RAM combination was well tolerated. CONCLUSIONS: The addition of RAM to FOLFIRINOX did not significantly impact PFS or OS. The combination was well tolerated (Funded by Eli Lilly; ClinicalTrials.gov number, NCT02581215).

Anticancer efficacy of KRASG12C inhibitors is potentiated by PAK4 inhibitor KPT9274 in preclinical models of KRASG12C mutant pancreatic and lung cancers.

KRASG12C inhibitors have revolutionized the treatment landscape for cancer patients harboring the G12C mutant isoform of KRAS. With the recent FDA approval of sotorasib and adagrasib, patients now have access to more promising treatment options. However, patients who receive these agents as a monotherapy usually develop drug resistance. Thus, there is a need to develop logical combination strategies that can delay or prevent the onset of resistance and simultaneously enhance the antitumor effectiveness of the treatment regimen. In this study, we aimed at pharmacologically targeting PAK4 by KPT9274 in combination with KRASG12C inhibitors in KRASG12C mutant pancreatic ductal adenocarcinoma (PDAC) and nonâ€"small cell lung cancer (NSCLC) preclinical models. PAK4 is a hub molecule that links several major signaling pathways and is known for its tumorigenic role in mutant Ras-driven cancers. We assessed the cytotoxicity of PAK4 and KRASG12C inhibitors combination in KRASG12C mutant 2D and 3D cellular models. KPT9274 synergized with both sotorasib and adagrasib in inhibiting the growth of KRASG12C mutant cancer cells. The combination was able to reduce the clonogenic potential of KRASG12C mutant PDAC cells. We also evaluated the antitumor activity of the combination in a KRASG12C mutant PDAC cell line-derived xenograft (CDX) model. Oral administration of a sub-optimal dose of KPT9274 in combination with sotorasib (at one-fourth of MTD) demonstrated significant inhibition of the tumor burden ( p = 0.002). Similarly, potent antitumor efficacy was observed in an NSCLC CDX model where KPT9274, acting as an adjuvant, prevented tumor relapse following the discontinuation of sotorasib treatment ( p = 0.0001). KPT9274 and sotorasib combination also resulted in enhanced survival. This is the first study showing that KRASG12C inhibitors can synergize with PAK4 inhibitor KPT9274 both in vitro and in vivo resulting in remarkably enhanced antitumor activity and survival outcomes. Significance: KRASG12C inhibitors demonstrate limited durable response in patients with KRASG12C mutations. In this study, combining PAK4 inhibitor KPT9274 with KRASG12C inhibitors has resulted in potent antitumor effects in preclinical cancer models of PDAC and NSCLC. Our results bring forward a novel combination therapy for cancer patients that do not respond or develop resistance to KRASG12C inhibitor treatment.

Dual IL-6 and CTLA-4 blockade regresses pancreatic tumors in a T cell- and CXCR3-dependent manner.

This study aimed to enhance antitumor immune responses to pancreatic cancer via Ab-based blockade of IL-6 and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Mice bearing s.c. or orthotopic pancreatic tumors were treated with blocking Abs to IL­6 and/or CTLA-4. In both tumor models, dual IL-6 and CTLA-4 blockade significantly inhibited tumor growth. Additional investigations revealed that dual therapy induced an overwhelming infiltration of T cells into the tumor as well as changes in CD4+ T cell subsets. Dual blockade therapy elicited CD4+ T cells to secrete increased IFN-γ in vitro. Likewise, in vitro stimulation of pancreatic tumor cells with IFN-γ profoundly increased tumor cell production of CXCR3-specific chemokines, even in the presence of IL-6. In vivo blockade of CXCR3 prevented orthotopic tumor regression in the presence of the combination treatment, demonstrating a dependence on the CXCR3 axis for antitumor efficacy. Both CD4+ and CD8+ T cells were required for the antitumor activity of this combination therapy, as their in vivo depletion via Abs impaired outcomes. These data represent the first report to our knowledge of IL-6 and CTLA­4 blockade as a means to regress pancreatic tumors with defined operative mechanisms of efficacy.

Combinatorial targeting of immune checkpoints and epigenetic regulators for hepatocellular carcinoma therapy.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. The five-year survival rate of patients with unresectable HCC is about 12%. The liver tumor microenvironment (TME) is immune tolerant and heavily infiltrated with immunosuppressive cells. Immune checkpoint inhibitors (ICIs), in some cases, can reverse tumor cell immune evasion and enhance antitumor immunity. Rapidly evolving ICIs have expanded systemic treatment options in advanced HCC; however, single-agent ICIs achieve a limited 15-20% objective response rate in advanced HCC. Therefore, other combinatorial approaches that amplify the efficacy of ICIs or suppress other tumor-promoting pathways may enhance clinical outcomes. Epigenetic alterations (e.g., changes in chromatin states and non-genetic DNA modifications) have been shown to drive HCC tumor growth and progression as well as their response to ICIs. Recent studies have combined ICIs and epigenetic inhibitors in preclinical and clinical settings to contain several cancers, including HCC. In this review, we outline current ICI treatments for HCC, the mechanism behind their successes and failures, and how ICIs can be combined with distinct epigenetic inhibitors to increase the durability of ICIs and potentially treat "immune-cold" HCC.

Medullary carcinoma of the ampulla has distinct clinicopathologic characteristics including common association with microsatellite instability and PD-L1 expression.

Medullary carcinomas have not yet been fully characterized in the ampulla. Here, 359 ampullary carcinomas (ACs) were reviewed and 11 medullary-type carcinomas (3%) were found and analyzed. In addition to the diagnostic medullary pattern, 6 showed focal mucinous and 8 had focal abortive gland-like formations. They occurred in younger patients (57 versus 65 y; P = .02), had larger invasion size (mean, 3.2 versus 1.9 cm; P = .01), formed nodular polypoid or plaque-like tumors, and often lacked preinvasive component. In addition to the lymphoplasmacytic infiltrates, they also had prominent eosinophils in 5 of 11 cases. Eight were papilla Vateri-NOS (not otherwise specified) tumors, 2 were ampullary-duodenal origin, 1 had a minor intra-ampullary papillary tubular neoplasm component, and none were ampullary-ductal. Although they had pushing-border infiltration, perineural and vascular invasion was common. They were strongly associated with DNA mismatch repair (MMR) protein deficient (7/11, 64%). The 5-yr survival rate (53%) appeared to be comparable with, and perhaps even better than that of nonmedullary ACs (47%), although this did not reach statistical significance (P = .47). Programmed cell death ligand-1 (PD-L1) expression levels were assessed in 8, and all 4 that were MMR deficient were positive both by combined positive score (CPS) ≥1 and tumor proportion score (TPS) ≥1, and of the 4 MMR proficient cases, 3 were positive by CPS; 2 by TPS. Overall, only 1 of the 8 available for analysis failed to show PD-L1 positivity by CPS. In contrast, nonmedullary MMR-deficient carcinomas expressed PD-L1 in only 33% of tumors by CPS, and none by TPS. One medullary carcinoma was also EBV associated. Unlike 'medullary carcinomas' of the kidney, INI1 was retained in all 8 cases tested. In conclusion, medullary carcinomas are 3% of ACs, have a strong association with MMR-D, and may be less aggressive despite their larger size. PD-L1 expression appears to be closely associated with medullary ACs regardless of MMR status, and thus targeted therapies can be considered for all medullary carcinomas of this site.