Current Standard Of Care Therapy Research Articles

Current Treatment Options for Renal Cell Carcinoma: Focus on Cell-Based Immunotherapy.

Renal cell carcinoma (RCC) affects over 400,000 patients globally each year, and 30% of patients present with metastatic disease. Current standard of care therapy for metastatic RCC involve TKIs and ICIs, including combinatorial strategies, but this offers only modest clinical benefit. Novel treatment approaches are warranted, and cell-based immunotherapies for RCC hold significant promise. These are currently being tested in the pre-clinical setting and in early phase clinical trials. Here, we review the landscape of cellular immunotherapy for RCC in the context of currently available therapies, with a particular focus on defining the current best antigenic targets, the range of cell therapy products being explored in RCC, and how advanced engineering solutions may further enhance these therapies in the RCC space.

BSLD-02 ELUCIDATING LEPTOMENINGEAL MICROENVIRONMENT CUES THAT PROMOTE METASTASIS AND CHEMOTHERAPY RESISTANCE IN HIGH-RISK MEDULLOBLASTOMA

Abstract Medulloblastoma is a molecularly heterogenous brain tumor of the cerebellum and is a leading cause of pediatric cancer mortality due to its propensity for leptomeningeal metastasis. Leptomeningeal metastasis occurs in over 20-30% of patients despite age- and risk- adapted chemoradiation therapy. The mechanisms responsible for medulloblastoma metastasis and therapy resistance remain incompletely understood. The leptomeninges represent a fundamentally distinct microenvironment from the primary cerebellar tumor. We hypothesized that unique signaling inputs from the cellular and extracellular milieu of the leptomeninges drive distinct medulloblastoma biology that leads to resistance to current standard of care therapy. We tested this hypothesis using Group 3-MYC amplified (Grp3-MA) cell lines given their high metastatic potential. Primary tumors grow within a glycosaminoglycan (hyaluronan) rich matrix while leptomeningeal metastases grow in a laminar fashion attached to leptomeningeal (pial) cells that were enriched for laminins, collagens, and fibronectin. Analogously, Grp3-MA cells grow in suspension at steady state, but subpopulations readily adhere to a leptomeningeal membrane mimetic in vitro. This attachment required integrin beta 1 (ITGB1) and promoted chemotherapy resistance. We additionally have created a novel co-culture model wherein medulloblastoma cells grow as adherent clusters on a layer of primary leptomeningeal cells in an ITGB1 dependent manner. We are using this co-culture platform to perform single cell RNA sequencing and ligand receptor analysis to understand how cell-cell communication between leptomeningeal cells and medulloblastoma cells promotes tumor cell growth. Collectively, our studies demonstrate that cues from the leptomeningeal microenvironment alter medulloblastoma cell behavior and are attractive targets for developing novel therapies against metastasis.

SPinal cOrd neUromodulatioN to treat Cerebral palsy in pEdiatrics: POUNCE Multisite Randomized Clinical Trial.

Cerebral palsy (CP) affects up to 4 children in 1,000 live births, making it the most common motor disorder in children. It impairs the child's ability to move voluntarily and maintain balance and posture, and results in a wide range of other functional disorders during early development impairments in various sensory modalities, e.g., vision, hearing ability and proprioception. Current standard of care therapy focuses on symptom management and does not mitigate the progression of many of these underlying neurological impairments. The goal of this trial is to conduct a prospective multicenter, double-blinded, sham-controlled, crossover, randomized control trial to demonstrate the safety and efficacy of noninvasive spinal cord neuromodulation (SCiP™, SpineX Inc.) in conjunction with activity-based neurorehabilitation therapy (ABNT) to improve voluntary sensorimotor function in children with cerebral palsy. Sixty participants (aged 2-13 years) diagnosed with CP classified as Gross Motor Function Classification Scale Levels I-V will be recruited and divided equally into two groups (G1 and G2). Both groups will receive identical ABNT 2 days/wk. G1 will initially receive sham stimulation, whereas G2 will receive therapeutic SCiP™ therapy for 8 weeks. After 8 weeks, G1 will cross over and receive therapeutic SCiP™ therapy for 8 weeks, whereas G2 will continue to receive SCiP™ therapy for another 8 weeks, for a total of 16 weeks. Primary and secondary outcome measures will include Gross Motor Function Measure-88 and Modified Ashworth Scale, respectively. Frequency and severity of adverse events will be established by safety analyses. The trial is registered on clinicaltrials.gov (NCT05720208). The results from this trial will be reported on clinicaltrials.gov, published in peer-reviewed journals and presented at scientific and clinical conferences.

Ensifentrine as a Novel, Inhaled Treatment for Patients with COPD.

Ensifentrine is a novel, potent, and selective dual inhibitor of phosphodiesterase (PDE)3 and PDE4 designed for delivery by inhalation that combines effects on airway inflammation, bronchodilation and ciliary function in bronchial epithelia. In Phase 2 studies in subjects with COPD, ensifentrine demonstrated clinically meaningful bronchodilation and improvements in symptoms and health-related quality of life when administered alone or in combination with current standard of care therapies. Ensifentrine is currently in late-stage clinical development for the maintenance treatment of patients with COPD. This review summarizes non-clinical data as well as Phase 1 and Phase 2 efficacy and safety results of nebulized ensifentrine relevant to the maintenance treatment of patients with COPD.

Abstract 33: Epidemiology, Diagnosis, and Outcomes of Pediatric Burkitt Lymphoma Patients Treated at Bugando Medical Centre in Mwanza, Tanzania

Abstract Purpose: Despite the significant improvement in outcomes over the last few decades for the treatment of pediatric Burkitt lymphoma, outcomes in sub-Saharan Africa remain poor, with an approximately 50% survival rate. This disparity is likely multifactorial and significant work remains to improve these outcomes in low resource settings. As a first step in attempting to improve these disparate outcomes at our hospital, Bugando Medical Centre (BMC), in Mwanza, Tanzania, we aim to improve the understanding of the presentation, diagnosis, and outcomes with the current standard of care therapy at our site. We propose that a better understanding of the current nature of care for these patients at our site will allow for more informed future interventions aimed at improving outcomes. Methods: Historical patient data were abstracted for pediatric patients with a diagnosis of Burkitt lymphoma treated at BMC from 2016-2022. Patients’ initial presentations (e.g. site of disease), means of diagnosis, treatment completion rate, and outcomes (if available) were analyzed. Results: Data were available on 109 patients with a diagnosis of Burkitt lymphoma between 2016-2022. Patients were on average 7.7 years old at presentation. We observed a 2:1 male to female ratio. We observed a significant proportion of abdominal disease with 58.7% presenting with abdominal disease (either alone or in combination) at initial diagnosis. There were 91% of patients who were deemed INCTR ‘high risk’ at diagnosis. There was a notable improvement in the percent of patients diagnosed with a biopsy with 46% in 2016 and 100% in 2022. Outcomes were poor but were difficult to assess with clarity due to a high rate of abandonment. Within those limitations, we observed a 1-year overall survival, of patients through 2021 with known outcomes, of 50.2% and a 1-year event free survival of 34.1% (including abandoment as an event). Conclusion: Overall, in our patients we note epidemiology consistent with known data for endemic Burkitt lymphoma. Our patient population includes a significant proportion of abdominal and/or high-risk disease. We demonstrate overall poor outcomes with a high degree of treatment abandonment. These data suggest that improvement in treatment efficacy and treatment adherence may improve outcomes. Citation Format: Hutton Chapman, Paul S. Ntemi, Jacqueline Kamanga, Judith Paschal, Heronima J. Kashaigili, Kristin Schroeder. Epidemiology, Diagnosis, and Outcomes of Pediatric Burkitt Lymphoma Patients Treated at Bugando Medical Centre in Mwanza, Tanzania [abstract]. In: Proceedings of the 11th Annual Symposium on Global Cancer Research; Closing the Research-to-Implementation Gap; 2023 Apr 4-6. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(6_Suppl):Abstract nr 33.

Current and emerging approaches to noncompetitive AR inhibition.

The androgen receptor (AR) has been shown to be a key determinant in the pathogenesis of castration-resistant prostate cancer (CRPC). The current standard of care therapies targets the ligand-binding domain of the receptor and can afford improvements to life expectancy often only in the order of months before resistance occurs. Emerging preclinical and clinical compounds that inhibit receptor activity via differentiated mechanisms of action which are orthogonal to current antiandrogens show promise for overcoming treatment resistance. In this review, we present an authoritative summary of molecules that noncompetitively target the AR. Emerging small molecule strategies for targeting alternative domains of the AR represent a promising area of research that shows significant potential for future therapies. The overall quality of lead candidates in the area of noncompetitive AR inhibition is discussed, and it identifies the key chemotypes and associated properties which are likely to be, or are currently, positioned to be first in human applications.

Abstract CT136: An open-label phase I/IIa study to evaluate the safety and efficacy of CCS1477 as monotherapy and in combination in patients with advanced hematological malignancies

Abstract Background Inobrodib (CCS1477) is a first in class potent, selective, and orally bioavailable inhibitor of the bromodomains of p300 and CBP, two closely related histone acetyl transferases with oncogenic roles in hematological malignancies. In pre-clinical studies inobrodib potently inhibited cell proliferation in acute myeloid leukemia (AML), multiple myeloma (MM) and non-Hodgkin lymphoma (NHL) cell lines. Inobrodib demonstrated dose-dependent efficacy in corresponding xenograft models, eliciting tumor regression at the highest doses. These effects were accompanied by significant reductions in expression of MYC, MYB and IRF4. Low doses of inobrodib also demonstrated good efficacy when added to standard-of-care treatments, providing a strong rationale for combination treatment in patients. Inobrodib represents a novel and differentiated approach and offers a potential new therapeutic option for patients who have relapsed or are refractory to current standard of care therapies in AML, higher risk MDS, MM or NHL. Study Design and Methods NCT04068597 is an adaptive multi-arm/multi-stage trial allowing exploration of p300/CBP inhibition as monotherapy or in combination with different agents across multiple indications including AML/higher risk MDS, MM, and NHL. The trial was initiated as a dose escalation rolling 6 design separately in AML/MDS and MM/NHL to ensure tolerability is explored separately across groups of indications, with the possibility to expand in monotherapy across different indications. Key inclusion criteria include patients with confirmed relapsed or refractory disease, with patients having received standard therapy (typically at least two prior lines of therapy). Response criteria are assessed using standard methodologies for the different indications. Blood and tumor samples are collected for exploratory biomarker analysis to understand mechanisms of response to treatment or disease progression. The recommended phase 2 dose/schedule has been determined, and monotherapy expansion arms are currently open in selected indications. Cohorts investigating dose escalation with standard of care agents pomalidomide/dexamethasone in MM as well azacytidine with or without venetoclax in AML or MDS are currently enrolling, with the possibility of expansion for promising combinations. An additional ‘rescue’ cohort for MM patient who failed inobrodib monotherapy will be used to determine whether addition of pomalidomide with or without dexamethasone may reverse resistance to inobrodib. This cohort will also explore tolerability and clinical activity of steroid-sparing combination regimen. Citation Format: Tomasz Knurowski, Emma Searle, Karen Clegg, Neil Pegg, William West, Debbie Haynes, Kristopher Frese, Tim C. Somervaille. An open-label phase I/IIa study to evaluate the safety and efficacy of CCS1477 as monotherapy and in combination in patients with advanced hematological malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT136.

Abstract 3396: Discovery of BDTX-1535, a novel 4th generation, irreversible, potent, wild type sparing EGFR MasterKey inhibitor that targets oncogenic kinase domain mutations as well as extracellular domain alterations for the treatment of NSCLC and GBM

Abstract Acquired resistance to 3rd generation EGFR inhibitors used in the treatment of NSCLC is common. While the EGFR C797S substitution is a frequently reported post-osimertinib resistance mutation, real world evidence indicates the emergence of additional EGFR alterations that can drive drug resistance: kinase domain mutations (e.g., S768I), extracellular domain alterations (e.g., EGFRvIII, A289X), and EGFR amplification. Moreover, while osimertinib targets the classical EGFR mutations, primary NSCLC tumors are also driven by other oncogenic kinase domain mutations including G719X, S768I, and L861Q, which confer de novo (intrinsic) resistance to 3rd generation EGFR TKIs. A family of extracellular domain alterations occurs in nearly 50% of GBM patients, and these alterations are clinically resistant to all current generation inhibitors. Real world data in GBM demonstrate these EGFR alterations often co-occur and persist throughout treatment with current standard of care therapy. Of critical importance is the observation that the oncogenic isoform of EGFR in GBM is a covalent homo-dimer which can be formed and paradoxically activated by the binding of reversible 1st generation EGFR inhibitors. There is a significant clinical need to develop a potent CNS penetrant EGFR inhibitor that would target both acquired and intrinsic resistance mutations expressed in NSCLC and co-occurring EGFR alterations in GBM. An effective inhibitor should meet four design principles; 1) potent and selective against a broad family of intracellular, extracellular EGFR oncogenic alterations and amplification, 2) wild type EGFR sparing, 3) irreversible to avoid paradoxical activation, and 4) CNS penetrant. BDTX-1535 is a 4th generation irreversible CNS penetrant EGFR MasterKey inhibitor targeting a family of oncogenic EGFR extracellular domain alterations and amplification in GBM patients and EGFR resistance mutations in NSCLC. BDTX-1535 meets all four criteria for a highly effective EGFR inhibitor and was designed using the MAP Discovery Engine to target the activated conformations used by oncogenic EGFR to drive tumorigenesis. BDTX-1535 achieves potent anti-tumor activity against EGFR alterations and amplification across models including NSCLC and GBM PDX and intracranial tumors. BDTX-1535 is currently in a phase I clinical study in patients with NSCLC and GBM harboring sensitive EGFR alterations (NCT05256290). Citation Format: Matthew O'Connor, Matthew Lucas, Sherri Smith, Anthony Trombino, Sudharshan Eathiraj, Elizabeth Buck. Discovery of BDTX-1535, a novel 4th generation, irreversible, potent, wild type sparing EGFR MasterKey inhibitor that targets oncogenic kinase domain mutations as well as extracellular domain alterations for the treatment of NSCLC and GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3396.

Abstract 2280: BG34-200 immunotherapy of advanced melanoma

Abstract Background: High levels of myeloid derived cells are characteristic of tumor microenvironment (TME) of advanced melanoma. These cells work with the tumor cells to suppress host development of anti-tumor immune responses, regulate tumor metastasis, and drive cancer drug resistance to virtually all types of therapy. Therefore, methods to disrupt tumor-associated myeloid cell function are actively being sought to find a cure. Goals: Our team has recently developed a plant-derived carbohydrate molecule, BG34-200, that modulates tumor-associated myeloid cells by targeting the cell surface receptor CD11b. In this study, we investigated the immune activation induced by BG34-200-CD11b engagement in the context of advanced melanoma and use the knowledge to develop BG34-200-based combination immunotherapy. Methods: Wild type B57Bl6/J mice were injected with 1.5million B16F10 cells and treated intravenously with BG34-200. Tumor volume and animals survival were monitored, and whole blood was drawn for FACS analysis. Results: We found that BG34-200 IV administration could significantly inhibit tumor growth and improve survival in B16F10 mice with advanced melanoma. Our data supported a model that the entry of BG34-200 into circulating melanoma tumor-associated inflammatory monocytes (TAIMs) could trigger a sequential immune activation: the BG34-200+ TAIM subsets migrated to tumor and differentiated into monocyte-derived dendritic cells (mo-DCs); then, the BG34-200+ mo-DCs migrated to tumor draining lymph nodes where they triggered the generation of tumor antigen specific T cells. Based upon these results, we combined BG34-200 treatment with adoptive transfer of TdLN-derived T-cell to treat advanced melanoma, which significantly improved animal survival and helped tumor-free survivors be resistant to a second tumor cell challenge. Conclusions: The scientific findings from this study will allow us to develop new technology to apply BG34-200-based immunotherapy to patients with advanced melanoma who have not responded to current standard of care therapies with and without immunotherapy. Citation Format: Veronique P. Roche, Victor Sandoval, Zachary Senders, Joshua Lyons, Claire Wolford, Mei Zhang. BG34-200 immunotherapy of advanced melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2280.

The HORIZON III retrospective exploratory analysis: HER2 expression amplification in colorectal cancer.

194 Background: Although regularly used in breast and gastric cancer, HER2 testing is not routinely performed in colorectal cancer (CRC). Immunohistochemistry (IHC) and in situ hybridization (ISH) scoring have not been optimized for assessment of HER2 overexpression and amplification in CRC. Varying rates of HER2 overexpression (2%-11%) have been reported in previously untreated CRC (Wang World J Gastrointest Oncol 2019) and patients with advanced/metastatic CRC with HER2 amplification or overexpression respond poorly to current standard of care therapies (Sartore-Bianchi Oncologist 2019). We characterized HER2 prevalence in a retrospective cohort analysis of clinical trial patients. Methods: The HORIZON III trial (NCT00384176) evaluated FOLFOX + bevacizumab or cediranib (AZD2171) as first-line (1L) treatment in patients with metastatic CRC (Schmoll J Clin Oncol 2012). The primary objective of this analysis of a subset of HORIZON III samples was to characterize HER2 prevalence in 1L metastatic CRC. Secondary and exploratory objectives included correlating HER2 status to other molecular findings (eg, RAS/RAF mutations), clinicopathologic characteristics, and patient outcomes. IHC was performed using a monoclonal anti-HER2 antibody PATHWAY HER2 [4B5] Ventana on primary CRC tumor sections and scored according to ASCO/CAP guidelines for gastric cancer (Bartley Arch Pathol Lab Med 2016). H&E staining was performed to determine the adequacy of tumor samples (ie, > 100 viable tumor cells per specimen). All tumors with an IHC score of 2+ were analyzed for amplification by ISH (HER2 IQFISH pharmDx dual probe kit, Agilent Technologies K573111-5). Targeted mutation panel testing was used to determine other molecular alterations. Descriptive statistics were used to summarize baseline and clinical outcome data by HER2 status. The current analysis was approved by the AstraZeneca bioethics review board. Results: Of the 1614 patients in HORIZON III, 396 met the inclusion criteria of appropriate consent, sufficient tumor sample for analysis, and a unique identifier. HER2-positive tumors (IHC3+ or IHC2+/ISH+) were identified in 2.1% of samples; 1.3% were IHC3+ and 0.8% were IHC2+/ISH+. Compared with IHC3+, IHC2+ tumors were more heterogeneous with mixed components of cells weakly expressing HER2 and lacking HER2 expression. Conclusions: This exploratory analysis of the HORIZON III study provides insights into HER2 prevalence in 1L, unselected, advanced/metastatic CRC, finding that 2.1% of tumors were HER2 positive. The demographic characteristics of patients with analyzable samples were representative of the entire HORIZON III study population; however, further assessment of KRAS status and other clinicopathological characteristics is needed. These data may inform future clinical development and support selection of patients with CRC who are likely to benefit from HER2 targeting therapies. Clinical trial information: NCT00384176 .

Reducing Dietary Acid With Fruit and Vegetables Versus Oral Alkali in People With Chronic Kidney Disease (ReDACKD): A Clinical Research Protocol.

Individuals with chronic kidney disease (CKD) can develop metabolic acidosis which, in turn, is associated with faster progression of CKD and an increased need for dialysis. Oral sodium bicarbonate (the current standard of care therapy for metabolic acidosis) is poorly tolerated leading to low adherence. Base-producing or alkalizing Fruit and vegetables have potential as an alternative treatment for metabolic acidosis as they have been shown to reduce acid load arising from the diet. This trial will evaluate the feasibility of providing base-producing fruit and vegetables as a dietary treatment for metabolic acidosis, compared with oral sodium bicarbonate. A 2-arm, open-label, dual-center, randomized controlled feasibility trial. Two Canadian sites: a nephrology clinic in Winnipeg, Manitoba, and a nephrology clinic in Halifax, Nova Scotia. Adult participants with G3-G5 CKD and metabolic acidosis. Participants will undergo baseline measurements and attend 5 study visits over 12 months at which they will have a measurement of feasibility criteria as well as blood pressure, blood and urine biochemistry, 5-repetition chair stand test (STS5), and questionnaires to assess quality of life and symptoms. Furthermore, participants fill out Automated Self-Administered 24-hour recalls (ASA-24) in the beginning, middle, and end of trial. A total of 40 eligible participants will be randomized 1:1 to either base-producing fruit and vegetables (experimental) group or sodium bicarbonate (control) group, beginning from a daily dose of 1500 mg. Using self-administered dietary assessments, lack of supervision over the consumption of study treatments and the possible disappointment of the control group for not receiving fruit and vegetables would be considered as limitations for this study. However, we are planning to undertake proper practices to overcome the possible limitations. These practices are discussed throughout the article in detail. This study will generate data on base-producing fruit and vegetables consumption as a dietary treatment for metabolic acidosis in CKD. The data will be used to design a future multi-center trial looking at slowing CKD progression in people with metabolic acidosis. This study is registered on clinicaltrials.gov with the identifier NCT05113641.

BG34-200 Immunotherapy of Advanced Melanoma.

High levels of myeloid-derived cells are characteristic of the tumor microenvironment (TME) of advanced melanoma. These cells interact with tumor cells to suppress the development of antitumor immune responses, regulate tumor metastasis, and drive cancer's resistance to virtually all types of therapy. Therefore, methods to disrupt tumor-associated myeloid cell function are actively being sought to find a cure. Our team has recently developed a plant-derived carbohydrate molecule, BG34-200, that modulates tumor-associated myeloid cells by targeting the cell surface receptor CD11b. In this study, we found that BG34-200 IV administration could significantly inhibit tumor growth and improve survival in B16F10 mice with advanced melanoma. Our data supported a model that the entry of BG34-200 into circulating melanoma tumor-associated inflammatory monocytes (TAIMs) could trigger a sequential immune activation: the BG34-200+ TAIM subsets migrated to tumor and differentiated into monocyte-derived dendritic cells (mo-DCs); then, the BG34-200+ mo-DCs migrated to tumor draining lymph nodes, where they triggered the generation of tumor-antigen-specific T cells. Based upon these results, we combined BG34-200 treatment with adoptive transfer of TdLN-derived T cells to treat advanced melanoma, which significantly improved animal survival and helped tumor-free survivors be resistant to a second tumor-cell challenge. The scientific findings from this study will allow us to develop new technology and apply BG34-200-based immunotherapy to patients with advanced melanoma who have not responded to current standard of care therapies with and without immunotherapy.

Acid Ceramidase (ASAH1) Is a Key Mediator of Drug Resistance in Refractory Multiple Myeloma

Despite the growing armamentarium of treatments including proteasome inhibitors (PIs), immunomodulatory imides (IMiDs) and cellular and non-cellular immunotherapies MM remains incurable, due to the emergence of drug resistance that causes patient relapse. To develop therapies that significantly extend overall survival, a clearer understanding of the mechanisms driving drug-resistance is urgently required. Analysis of RNA-seq data derived from 672 MM Moffitt patients revealed that sphingolipid metabolism genes and in particular acid ceramidase (ASAH1), are significantly enriched in relapse MM (RMM). Further, high levels of ASAH1 in RMM patients predicted poorer overall survival when patients were treated with any PI-containing regimen (median overall survival 552 vs 1226 days). These findings were corroborated in the Multiple Myeloma Research Foundation CoMMpass dataset (IA17). Next, we queried potential mechanisms of treatment resistance using gene-set enrichment analysis (GSEA). ASAH1 High patients displayed upregulation of gene signatures involved in metabolism of lipids, sphingolipids and regulation of apoptosis. Further, PI-resistant cell lines (U266-PSR, RPMI8226-B25, and ANBL6-V10R) displayed elevated levels of ASAH1, and total and phosphorylated levels of anti-apoptotic proteins MCL-1 and BCL-2 compared to PI-sensitive parental cells (U266, RPMI8226 and ANBL6). Genetic (shRNA) and pharmacological (ceranib-2) inhibition of ASAH1 significantly decreased MM viability and reduced MCL-1/BCL-2 expression. Further, ASAH1 inhibition resensitized resistant MM cells to PI treatment. Importantly, we recapitulated our findings in CD138+ patient MM cells ex vivo (EMMA platform), with ceranib-2/PI treatment being synergistic in the majority (>75%) of patient samples tested. In vivo, ceranib-2 treatment limited PI-resistant U266-PSR MM tumor growth and extended overall survival of NSG mice. Further, ASAH1 depletion (shRNA) resensitized MM cells to PI treatment in vivo and loss of MCL-1 and BCL-2 expression was confirmed ex vivo. To understand the mechanism through which ASAH1 mediates PI-resistance we performed total and pSTY proteomic profiling (LC-MS/MS). Proteomic analyses revealed inhibition of the endogenous phosphatase PP2A inhibitor, I2PP2A as a candidate mechanism. Notably, I2PP2A was elevated in PMRC RMM patient samples, correlating with ASAH1 expression, and predicting poorer overall survival. In conclusion, in vitro, in vivo and patient ex vivo data demonstrate ASAH1 is a novel, clinically relevant and tractable target for the treatment of PI-resistant MM. Future studies to develop novel and potent ASAH1 inhibitors for the treatment resistant MM, in combination with current standard of care therapies are on-going and we believed warranted based on our emerging data.

Abstract IA018: ATP production in pancreas cancer and tumor infiltrating lymphocytes

Abstract Diet can influence both the microbiome and (at least in mice) the outcomes of pancreas cancer therapy. For example, ketogenic diet can synergize with either current standard of care therapy ( gemcitabine + nab-paclitaxel) or PI3K inhibition in mouse models of pancreas cancer. I will discuss our recent work exploring how diet interacts with the microbiome, and how such interactions may influence pancreas cancer chemotherapy response. A simple hypothesis for how diet influences microbiome composition is that certain microbes prefer certain nutrients, and diets high in those nutrients lead to outgrowth of those microbes. To enable testing of this hypothesis, we developed isotope-tracer strategies that directly measure the nutrient preferences of different members of the gut microbiome. I will describe this new technology and its application to support the above hypothesis. I will further describe experiments manipulating diet and/or microbiome to influence the response of pancreas cancer to PI3K inhibition. The longterm goal is to understand, at a biochemical level, the links between diet, microbiome, and the effectiveness of cancer therapy, and to develop translatable strategies for manipulating metabolism via diet to improve therapeutic outcomes. Citation Format: Joshua D. Rabinowitz. ATP production in pancreas cancer and tumor infiltrating lymphocytes [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr IA018.

204. THE TUMOUR IMMUNE MICROENVIRONMENT IN OESOPHAGEAL ADENOCARCINOMA HAS PROGNOSTIC SIGNIFICANCE

Abstract Oesophageal adenocarcinoma (OAC) is a deadly disease with an increasing incidence globally. Treatment outcomes with traditional therapy have largely plateaued and responses to immunotherapy are modest at best, necessitating the need for better biomarker driven selection. We aimed to unravel the tumour neoantigen landscape and immune microenvironment in OAC patients to aid improved patient selection and inform novel immunotherapy trials. To characterise the tumour immune microenvironment and neoantigen landscape of OACs, we performed DNA sequencing (n = 117) and RNA sequencing (n = 115) on biopsies taken at pre-treatment endoscopy. Using expression-based computational methods we analysed transcriptomic data to profile infiltration levels of 28 immune cell populations and their functional orientation, as well as stromal signatures and immune checkpoint molecules. TCGA data was used for as a validation cohort. Tumour neoantigens were predicted using the pVAC-Seq pipeline. Using an immune based classification based on the tumour microenvironment composition, we identified three distinct phenotypes; immune-enriched (IE), heterogeneously-infiltrated (HI), and immune-cold (IC). The IE group showed improved survival compared to both HI and IC, with HI showing the worst survival. The HI-group showed no difference in stromal scores to the IE group, but showed significantly decreased adaptive-immune cell infiltration, indicating that an immunosuppressive stromal compartment may be driving outcomes for these patients. No difference was seen in total or quality neoantigen load between groups, but high correlation with antigen processing machinery is seen. Our analysis expands the knowledge of the relatively unknown tumour immune microenvironment of OAC. We have identified three immune TME-phenotypes with prognostic utility with current standard of care therapies; which may also act as potential immunotherapy biomarkers. This is being explored further in ongoing immune microenvironment research and will guide future translational studies.

Combinatorial treatments of tamoxifen and SM6Met, an extract from Cyclopia subternata Vogel, are superior to either treatment alone in MCF-7 cells.

Synergistic drug combinations are not only popular in antibiotic, anti-microbial, immune disease (i.e., AIDS) and viral infection studies, but has also gained traction in the field of cancer research as a multi-targeted approach. It has the potential to lower the doses needed of standard of care (SOC) therapeutic agents, whilst maintaining an effective therapeutic level. Lower dosages could ameliorate the fundamental problems such as drug resistance and metastasis associated with current SOC therapies. In the current study, we show that the combination of SM6Met with (2)-4-hydroxytamoxifen (4-OH-Tam, the active metabolite of tamoxifen) produces a strong synergistic effect in terms of inhibiting MCF7 ER-positive (ER+) breast cancer cell proliferation and that a 20 times lower dose of 4-OH-Tam in combination with SM6Met is required to produce the same inhibitory effect on cell proliferation as 4-OH-Tam on its own. Cell cycle analyses of the best combination ratios of SM6Met and 4-OH-Tam also suggests that the combination results in increased accumulation of cells in the S-phase and in the apoptotic phase. Moreover, the best combination ratio (20:1) of SM6Met with 4-OH-Tam displayed greater anti-metastatic potential in terms of inhibiting ER+ breast cancer cell migration, invasion, and colony formation than the SOC therapy alone, suggesting that SM6Met together with 4-OH-Tam could be a viable drug combination for not only delaying resistance and ameliorating the negative side-effects associated with current SOC therapies, like tamoxifen, but could also provide a novel, more affordable therapeutic alternative for treating or preventing ER+ breast cancer metastasis.

Challenges in Glioblastoma Radiomics and the Path to Clinical Implementation

Simple SummaryGlioblastoma (GBM) is a cancer with poor prognosis, its 5-year survival expectation is approximately 5%. Advances in oncologic treatment techniques have not led to significant improvements in survival outcomes for GBM patients. Part of the reason for the treatment failures in GBM patients is that treatments fail to account for heterogeneities both within and between different tumors. Radiomics is a rapidly emerging research field that examines the relationship between medical imaging features and patient clinical outcomes and biological characteristics of tumours. This review outlines the applications of radiomics for GBM patient management and the barriers facing the implementation of radiomics into clinical practice. In completing this review, we hope to inform clinicians and researchers on how radiomics may be used to improve patient clinical outcomes.Radiomics is a field of medical imaging analysis that focuses on the extraction of many quantitative imaging features related to shape, intensity and texture. These features are incorporated into models designed to predict important clinical or biological endpoints for patients. Attention for radiomics research has recently grown dramatically due to the increased use of imaging and the availability of large, publicly available imaging datasets. Glioblastoma multiforme (GBM) patients stand to benefit from this emerging research field as radiomics has the potential to assess the biological heterogeneity of the tumour, which contributes significantly to the inefficacy of current standard of care therapy. Radiomics models still require further development before they are implemented clinically in GBM patient management. Challenges relating to the standardisation of the radiomics process and the validation of radiomic models impede the progress of research towards clinical implementation. In this manuscript, we review the current state of radiomics in GBM, and we highlight the barriers to clinical implementation and discuss future validation studies needed to advance radiomics models towards clinical application.

Amivantamab in patients with NSCLC with MET exon 14 skipping mutation: Updated results from the CHRYSALIS study.

9008 Background: Amivantamab, a fully human bispecific antibody targeting epidermal growth factor receptor (EGFR) and MET, is approved for the treatment of non-small cell lung cancer (NSCLC) with EGFR exon 20 insertion after prior platinum-based chemotherapy. Given its bispecific nature, amivantamab is being explored in patients (pts) with primary MET exon 14 skipping mutation (METex14) in the MET-2 cohort of the CHRYSALIS study. Methods: CHRYSALIS (NCT02609776) is an ongoing phase 1 dose escalation/dose expansion study of amivantamab in pts with advanced NSCLC. Pts with primary METex14 whose disease progressed on or who declined current standard of care therapy were treated with amivantamab 1050 mg (pts <80 kg) or 1400 mg (pts ≥80 kg) weekly in cycle 1 and biweekly thereafter. Response was assessed by investigators using RECIST v1.1. Results: As of 2 Dec 2021, 43 pts with METex14 had received amivantamab. Median age was 70 y (range, 43-88), 58% were women, median prior lines of therapy was 2 (range, 0-10) [eg, crizotinib (n=13), capmatinib (n=11), tepotinib (n=5), anti-MET antibody (n=1)], and 23% had history of brain metastases at baseline. In 36 pts with ≥1 postbaseline disease assessment, median duration of follow-up was 5.8 months (range, 0.3-15.8); 6 pts had no prior treatment, 11 had no prior MET inhibitor, and 19 had a prior MET inhibitor. Overall response rate was 33% (50% [3/6] in treatment-naïve pts, 46% [5/11] in pts with no prior MET inhibitor, and 21% [4/19] in pts with prior MET inhibitor therapy). Clinical benefit rate was >54% regardless of prior treatment (Table). Median duration of response (DOR) was not reached (range, 2.1-12.2 months); 67% (8/13) had DOR ≥6 months. Ten of the 12 responders remain on treatment (6.0-14.4 months) with ongoing responses; 2 discontinued after 2 and 12 months, respectively. Safety profile was consistent with previously reported experience of amivantamab (Sabari 2021 JTO 16(3):S108-109). Treatment-related adverse events leading to dose reduction or discontinuation occurred in 3 pts, each. Conclusions: Amivantamab demonstrates anti-tumor activity in primary METex14 NSCLC including after prior MET inhibitor treatment. Enrollment is ongoing and updated data will be shown. Clinical trial information: NCT02609776. [Table: see text]

Hearing Loss in Congenital CMV Disease Post-Ganciclovir

Source: Lanzieri TM, Caviness AC, Blum P, et al. Progressive, long-term hearing loss in congenital CMV disease after ganciclovir therapy. J Pediatric Infect Dis Soc. 2021;piab095. doi:10.1093/jpids/piab095Investigators from the CDC, Atlanta, GA, and Baylor College of Medicine, Houston, TX, conducted a study to assess long-term hearing outcomes in children with symptomatic congenital cytomegalovirus (CMV) infection, and the impact of ganciclovir therapy on hearing loss. For the study, they analyzed data from children born 1983–2005 who were enrolled in the Congenital CMV Longitudinal Study. All study participants had CMV infection detected in urine samples in the first 3 weeks of life and had microcephaly, chorioretinitis, neurologic abnormalities or evidence of reticuloendothelial system involvement (eg, petechiae/purpura). Study children had longitudinal assessments of hearing with auditory brainstem response testing and behavioral audiometry; those with hearing thresholds >20 dB were classified as having sensorineural hearing loss (SNHL). SNHL was defined as congenital if diagnosed in the first month of life. Study children were placed into 3 groups: Group A included patients who had been enrolled in a clinical trial and received ganciclovir; group B included children with SNHL, microcephaly and/or chorioretinitis but who were untreated; and group C comprised those without any of these findings who also were not treated with ganciclovir. The primary study outcome was long-term assessment of hearing loss among children in these 3 groups.Data were analyzed on 76 children; 17 (22%) in group A, 27 (36%) in group B, and 32 (42%) in group C. Among the 17 children in group A, 16 had microcephaly, chorioretinitis, or congenital SNHL; median duration of ganciclovir treatment in these patients was 40 days. Overall, the most common findings in study patients when they were neonates were purpura/petechiae (82% of those in group A, 78% in group B, and 63% in group C); 71% and 70%, respectively, of those in groups A and B had microcephaly. Congenital SNHL was diagnosed in 65% of patients in group A and 56% for those in group B, although hearing was not assessed in the first month of life in all study participants. The median age at last hearing assessment was 13 years for children in groups A and C and 11 years for those in group B. At that time, 16 (94%) patients in group A, 24 (89%) children in group B, and 16 (50%) group C patients had SNHL. SNHL was categorized as severe (>70 dB) in 12 (71%), 16 (59%), and 7 (22%) children, respectively, in groups A, B, and C.The authors conclude that most children in this study with congenital CMV infection developed substantial SNHL with or without ganciclovir treatment.Dr Brady has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.The current investigators provide long-term hearing outcomes for infants born 1983–2005 who were enrolled in the Congenital CMV Longitudinal Study. Participants were selected based on having severe disease as newborns.1,2 Not surprisingly, most developed substantial SNHL. As previously discussed, symptomatic congenital CMV infection at birth is a risk factor for SNHL. (See AAP Grand Rounds. 2019;42[5]:57.)3 Many infants also had microcephaly and/or head CT scan findings suggesting tissue destruction or dysplastic growth, which also are associated with an increased risk of SNHL.4 The results of early clinical trials of intravenous ganciclovir1,2 had suggested short-term stabilization or improvement in hearing at 6 months but were not borne out by the current investigation.With the introduction of oral valganciclovir, a phase III, randomized, placebo-controlled clinical trial, conducted during 2008– 2011, evaluated 6 weeks versus 6 months of therapy with valganciclovir.5 There was modest improvement in hearing and developmental outcomes at 12 and 24 months. Based on this trial, the AAP currently recommends 6 months of oral valganciclovir for infants with moderately to severely symptomatic congenital CMV infection who can start treatment in the first month of life.6 The current authors state that their findings cannot be extrapolated to infants who receive current standard of care therapy. Infants receiving valganciclovir are being followed to determine their long-term hearing outcomes.Another area that is not addressed is the role of valganciclovir for infants with congenital CMV infection who have isolated SNHL. The 2017 consensus guidelines do not routinely recommend valganciclovir for these infants based on insufficient evidence. Pasternak et al reported that 12 months of antiviral therapy for infants with congenital CMV infection and isolated SNHL led to improved hearing, but their study did not include a control group.(See AAP Grand Rounds. 2018;40[5]:55.)8Infants with congenital CMV infection are at risk for SNHL despite receipt of antiviral therapy. These infants deserve close audiology follow-up.The apparent lack of major benefit of antiviral therapy in children with symptomatic congenital CMV infection underscores the need for prevention. Neither CMV-IGIV nor investigational vaccines have yet proven efficacious.6

Abstract P2-05-02: Low molecular weight cyclin E facilitate replication stress tolerance in breast cancer development

Abstract Low Molecular Weight Cyclin E (LMW-E) are the tumor specific, oncogenic forms of cyclin E that are post translationally generated by neutrophil elastase (NE) mediated cleavage of the 50 KDa full-length cyclin E1 (FL-cycE, encoded by CCNE1 gene). While FL-cycE localizes mainly to the cell nucleus, LMW-E lack the N-terminus nuclear localization signal and are detected in both the nucleus and cytoplasm. Compared to FL-cycE, LMW-E exhibit longer half-life and higher affinity to their kinase partner CDK2 and are resistant to natural CDK inhibitors such as p21 and p27. It is currently assumed that LMW-E drive the tumorigenic process by promoting G1/S cell cycle transition and accelerating mitotic exit. Here we report that LMW-E overexpression also promotes genomic instability by deregulating DNA replication in a CDC6 dependent manner. To this end, we developed an immunohistochemistry (IHC) assay with a cyclin E antibody that can identify LMW-E expressing tumors and examined the association of genetic instability of each tumor with LMW-E status in 2 different cohorts of breast cancer patients. Cohort 1 is a retrospective cohort of 725 patients with stage I-II breast cancer treated at MD Anderson (Houston, TX) between 1985 and 1999. Cohort 2 is a prospective cohort of 85 patients with stage I-II breast cancer who enrolled in our study at MD Anderson between January 2000 and June 2010. Our results show that positive LMW-E status in stage 1 or 2 breast cancer patients correlates with increasing copy number variations, as identified by Molecular Inversion Probe (MIP) in cohort 1 and somatic mutations, as identified by Whole Exome Sequencing (WES) in cohort 2. Second, using immortalized human mammary epithelial cells (hMECs) engineered to express doxycycline inducible LMW-E or FL-cycE in CCNE1 knock-out background, we found that FL-cycE over-expression leads to DNA damage, cell cycle arrest and cell death. LMW-E overexpression, on the other hand, facilitates cell proliferation with damaged DNA, resulting in multi-nuclei and micro-nuclei formation in daughter cells. Third, overexpression of FL-cycE reduces chromatin bound MCM complex, while LMW-E overexpression promotes the chromatin loading of pre-replication complex including MCMs. Lastly, we show that LMW-E but not FL-cycE is the major form of cyclin E that binds to the chromatin. Specifically, in both LMW-Einducible hMECs and LMW-Ehighbreast tumor cell lines, CDC6 is required for the nuclear translocation and chromatin loading of LMW-E. Our findings have revealed the unique oncogenic function of LMW-E in deregulating replication licensing, promoting replication stress tolerance and genomic instability that fuels tumor development. These findings also provide potential novel therapeutic strategies for treating LMW-Ehigh breast tumors, who do not respond to the current standard of care therapies. Citation Format: Mi Li, Kwang Huei Low, Tuyen Bui, Kelly K Hunt, Khandan Keyomarsi. Low molecular weight cyclin E facilitate replication stress tolerance in breast cancer development [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-05-02.