Oncology Therapeutics Research Articles

Abstract 1369: Predicting clinical pharmacokinetics and toxicity of current and emerging oncology therapeutics by normothermic perfusion of isolated human-sized organs

Abstract Novel cancer therapeutics have less than a 12% probability of translating from bench to bedside. Unwarranted toxicity and inadequate therapeutic delivery due to uptake by clearance organs, not predicted by current preclinical methods, have contributed towards this high rate of attrition. In the present work, we propose normothermic machine perfusion of human or human-sized organs as a more predictive, closer-to-human model to investigate drug pharmacokinetics and toxicity. Over the past decade, developments in the field of organ preservation for transplantation have enabled prolonged (>12 hours) normothermic machine perfusion (NMP) of isolated porcine or human organs ex vivo, maintaining quasi-physiological haemodynamic, synthetic and metabolic function using a packed red cell perfusate with physiological oxygenation and nutrient levels at normal body temperature. This preserves physiological processes such as metabolism and drug elimination, and enables easy access to tissue, blood and excreted biological fluids, with NMP livers producing bile and NMP kidneys producing urine. We hypothesise that this will provide a physiologically relevant platform to investigate drug pharmacokinetics and toxicity. We selected a widely used small-molecule chemotherapeutic (Irinotecan hydrochloride 2mg/ml, Medac, UK) which has seen decades of clinical use and benefits from extensive clinical pharmacokinetic data. The small-molecule drug was infused into isolated porcine and human livers and kidneys, with quantification of concentration time profiles of the prodrug and its main metabolites in plasma, bile and urine over 16-24 hours of NMP. In addition to irinotecan (CPT11), three of its metabolites (APC, SN38G, SN38) were successfully detected and quantified, demonstrating peak plasma concentrations (Cmax ~ 10,000 ng/mL, 1000 ng/mL, 100 ng/g, 30 ng/g), plasma decay rates and percentages of injected dose in bile (%ID ~20%, 8%, 25%, 1%) and urine (%ID ~20%, 0.06%, 0.5%,0.1%) that are comparable to clinical data. Drug-tissue toxicity could also be adequately replicated in the NMP model. In conclusion, we have demonstrated that human-sized isolated, normothermically perfused livers and kidneys accurately represent the clinically observed pharmacokinetic and toxicity profiles of an established small-molecule therapeutic. Further model validation is ongoing for biologics and other nanomedicines which are susceptible to clearance by the mononuclear phagocytic system or are hepato- or nephrotoxic. If this proves successful, normothermic machine perfusion of isolated porcine and human organs could greatly aid the early screening of candidate therapeutics and significantly enhance the pace and success rate with which they are translated into patients. Citation Format: Tamsyn Clark, Luca Bau, Fungai Dengu, Daniel Voyce, Robert Carlisle, Peter Friend, Constantin Coussios. Predicting clinical pharmacokinetics and toxicity of current and emerging oncology therapeutics by normothermic perfusion of isolated human-sized organs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1369.

Assessment of gender representation in clinical trials leading to FDA approval for oncology therapeutics between 2014 and 2019: A systematic review-based cohort study.

Ensuring representative data accrual in clinical trials is important to safeguard the generalizability of results and to minimize disparities in care. This study's goal was to evaluate differences in gender representation in trials leading to US Food and Drug Administration (FDA) cancer drug approvals. An observational study was conducted from January 2014 to April 2019 using PubMed and the National Institutes of Health trials registry for primary trial reports. The National Cancer Institute's Surveillance, Epidemiology, and End Results program and US Census were consulted for national cancer incidence. The outcome was an enrollment incidence disparity (EID), which was calculated as the difference between male and female trial enrollment and national incidence, with positive values representing male overrepresentation. There were 149 clinical trials with 59,988 participants-60.3% and 39.7% were male and female, respectively-leading to 127 oncology drug approvals. The US incidence rates were 55.4% for men versus 44.6% for women. Gender representation varied by specific tumor type. Most notably, women were underrepresented in thyroid cancer (EID, +27.4%), whereas men were underrepresented in soft tissue cancer (EID, -26.1%). Overall, women were underrepresented when compared with expected incidence (EID, +4.9%; 42% of trials). For many specific tumor types, women are underrepresented in clinical trials leading to FDA oncology drug approvals. It is critical to better align clinical trial cohort demographics and the populations to which these data will be extrapolated. This study assesses whether gender disparities exist in clinical trials leading to US Food and Drug Administration (FDA) cancer drug approvals. From January 2014 to April 2019, 149 clinical trials leading to FDA oncology drug approvals showed 60.3% and 39.7% of the enrollees were male and female, respectively. Gender representation varied by specific tumor when compared with the expected incidence rate of cancer in the United States, although women were more often underrepresented. Increased efforts are needed with regard to ensuring equitable representation in oncology clinical trials.

PCN185 Identification of Gaps and Opportunities for Provincial Reimbursement of Oncology Companion Diagnostics in Canada

Companion diagnostics (CDx) are administered prior to treatment with a therapeutic. Within oncology, CDx detect single biomarkers or genes. The Canadian Agency for Drugs and Technologies in Health (CADTH) review process incorporates CDx, with guidance on inclusion in economic evaluations for therapeutics, though it does not provide funding recommendations. Funding decisions for genetic tests are made provincially. This research aims to identify where in the reimbursement pathway of CADTH-participating provinces do gaps exist in patient access to oncology therapeutics and the associated CDx.

Proteome and phospho-proteome profiling for deeper phenotype characterization of colorectal cancer heterogeneity.

e15536 Background: The rise of precision oncology therapeutics requires deep understanding of the molecular mechanisms implicated in cancer biology. Colorectal cancer (CRC) is one of the first solid tumors to be molecularly characterized by defined genes and pathways. Advances in tumor profiling have revealed a profound molecular heterogeneity in CRC leading to the definition of several consensus molecular subtypes (CMS). However, this molecular heterogeneity is still largely defined on the genomic and transcriptomics level. To complement the understanding of genetically defined molecular subgroups, we performed large-scale deep proteomic and phospho-proteomic profiling of CRC patient biopsies and adjacent healthy control tissue, which has enabled to explore the phenotype and obtain more functional insights in cancer biology. Methods: Sample processing from 5-10 mg of tissue per sample was performed using a liquid handling robot. Phospho-peptide enrichment was carried out with a Kingfisher Flex device and MagReSyn Ti-IMAC magnetic beads. Data-Independent Acquisition (DIA) LC-MS/MS was performed on multiple platforms consisting of a Thermo Scientific Q Exactive HF-X mass spectrometer coupled to a Waters M-Class LC. Chromatography was operating at 5 µL/min, and separation was achieved using 45 min (whole proteome) and 60 min (phospho-proteome) gradients. Results: Indivumed has built IndivuType, the world’s first multi-omics database for individualized cancer therapy, analyzing the highest quality cancer biospecimens to generate the most comprehensive dataset, including genomics, transcriptomics, proteomics, and clinical outcome information. Enabled by the DIA technology, a mass spectrometric method developed by Biognosys that obtains peptide fragmentation data in a highly parallelized way with high sensitivity, more than 7,000 proteins in the whole proteome and 20,000 phospho-peptides in the phospho-proteome workflow were profiled across more than 900 resected tissue samples of various CMS of CRC. The resulting proteome and phospho-proteome data were integrated into the IndivuType database and cross-analyzed with genomic and transcriptomic markers. Through this combined analysis, novel insights in clinically relevant signaling pathways in CRC subtypes were revealed. Conclusions: The deep phenotypic profiling of cancer samples, using next generation proteomics and phospho-proteomics, has enabled us to go beyond the genomic level in the characterization of tumor molecular heterogeneity. This multi-omics approach provides a solid foundation to advance the understanding of cancer biology, unravel key molecular events, and support the identification of novel therapeutic targets for precision medicine in CRC.

Building a Cancer Testing Juggernaut: NeoGenomics leverages key acquisitions to become and to make dominant cancer testing lab in the U.S. and now eyes international markets

Building a Cancer Testing Juggernaut: NeoGenomics leverages key acquisitions to become and to make dominant cancer testing lab in the U.S. and now eyes international markets

Recent Advances in Oligonucleotide Therapeutics in Oncology.

Cancer is one of the leading causes of death worldwide. Conventional therapies, including surgery, radiation, and chemotherapy have achieved increased survival rates for many types of cancer over the past decades. However, cancer recurrence and/or metastasis to distant organs remain major challenges, resulting in a large, unmet clinical need. Oligonucleotide therapeutics, which include antisense oligonucleotides, small interfering RNAs, and aptamers, show promising clinical outcomes for disease indications such as Duchenne muscular dystrophy, familial amyloid neuropathies, and macular degeneration. While no approved oligonucleotide drug currently exists for any type of cancer, results obtained in preclinical studies and clinical trials are encouraging. Here, we provide an overview of recent developments in the field of oligonucleotide therapeutics in oncology, review current clinical trials, and discuss associated challenges.

Infiltrating solid tumors with engineered T cells

<div class="authors authors-lg"><div class="author"><div class="author-img"><img src="https://cdn.insights.bio/uploads/Alfonso 200x200.png" data-image="1"></div><div class="author-det"> <b>Alfonso Quintás-Cardama</b> joined TCR² Therapeutics in 2017 as Chief Medical Officer. He brings nearly two decades of experience leading clinical strategy and regulatory filings for multiple oncology therapeutics resulting in market approval. Dr. Quintás-Cardama was the clinical development head of the Cell &amp; Gene Therapies Unit at GlaxoSmithKline where he was responsible for the full clinical development strategy, execution and collaboration with Adaptimmune on affinity enhanced T-cell therapies. Previously, he served as Global Clinical Leader of Novartis’ now approved Kymriah™ (tisagenlecleucel) CTL019 program and was an Assistant Professor in the Department of Leukemia at MD Anderson Cancer Center. Dr. Quintás-Cardama earned his MD from the Universidad de Santiago de Compostela School of Medicine in Spain. He completed an internship and residency in the Department of Medicine, Albert Einstein College of Medicine in New York and a Hematology and Oncology fellowship at The University of Texas, MD Anderson Cancer Center. </div></div></div>

Exploring the Mitochondrial Apoptotic Cell Death Landscape and Associated Components Serving as Molecular Targets, Primarily for Synthetic and Natural Drugs Targeting Oncology Therapeutics.

The role of mitochondria in the apoptosis signaling cell death pathway is regulated by extrinsic and intrinsic pathway, encompassing multiple components like the Bcl-2 family of proteins, death receptors, caspases, Smac/DIABLO, IAPs, Omi/HtrA2 and cytochrome c. These entities serve as effective molecular targets for numerous drugs targeting mitochondrial apoptotic pathways, mainly emphasizing oncology therapeutics. Defective apoptosis is an acquired hallmark of cancer cells, which promotes the establishment of apoptosis-targeting anti-cancer drugs in cancer treatment. The review provides an overview of the Bcl-2 inhibiting, IAPs antagonizing, caspase inhibiting and BH3 mimicking actions, mediated by anti-cancer drugs, rendering beneficial outcomes in different forms of cancer. The authors elaborate on the significance of synthetic and natural agents, targeting the mitochondrial apoptotic pathway, in ameliorating tumor cell growth in the body, and the specificity and effectiveness of these agents, motivating the researchers to explore mitochondrial apoptosis targeting of anti-tumor drugs of both herbal and synthetic origin. Thus, the review aims to predict this dynamic approach in oncology, simultaneously highlighting the challenges and future prospects, providing an opportunity to the experts to "go over with a fine tooth comb" in understanding this "programmed cell death pathway", and establishing reliability and accuracy of this therapeutic paradigm in the upcoming future.

Prospects for Radiopharmaceuticals as Effective and Safe Therapeutics in Oncology and Challenges of Tumor Resistance to Radiotherapy.

The rapid advances in nuclear medicine have resulted in significant advantages for the field of oncology. The focus is on the application of radiopharmaceuticals as therapeuticals. In addition, the latest developments in cell biology (the understanding of the cell structure, function, metabolism, genetics, signaling, transformation) have given a strong scientific boost to radiation oncology. In this regard, the article discusses what is soon going to be a new jump in radiation oncology based on the already accumulated considerable knowledge at the cellular level about the mechanisms of cell transformation and tumor progression, cell response to radiation, cell resistance to apoptosis and radiation and cell radio-sensitivity. The mechanisms of resistance of tumor cells to radiation and the genetically determined individual sensitivity to radiation in patients (which creates the risk of radiation-induced acute and late side effects) are the 2 major challenges to overcome in modern nuclear medicine. The paper focuses on these problems and makes a detailed summary of the significance of the differences in the ionizing properties of radiopharmaceuticals and the principle of their application in radiation oncology that will shed additional light on how to make the anti-cancer radiotherapies more efficient and safe, giving some ideas for optimizations.

Palliative ("Toilet") Mammectomy, A Decision-Making Dilemma - Short Review.

Breast cancer is one of the most severe health issues globally, but the therapy advancements and the constant adaptation of treatment protocols radically changed its prognoses. This article review of the literature from a surgical perspective, thus allowing for the optimum detection and placement of its role and benefits in the surgical and oncology therapeutics. The role of surgery becomes controversial, with sometimes "pretentious" techniques, hard to quantify benefits and challenges that require a thorough assessment prior to opting for surgery. Another interesting aspect is the relative lack of guidelines for such cases with an extreme lesion plurimorphism. This is the very reason for the term "advanced breast cancer" NOT covering all possible situations, leaving room for niches difficult to frame within a therapy plan.

Billion dollar deals end 2020 for big pharma

A string of billion dollar deals, many focused on the development of oncology therapeutics, rounded off an extraordinary year. A string of billion dollar deals, many focused on the development of oncology therapeutics, rounded off an extraordinary year.

Cancer Stem Cell (CSC) Inhibitors in Oncology-A Promise for a Better Therapeutic Outcome: State of the Art and Future Perspectives.

Cancer stem cells (CSCs), a subpopulation of cancer cells endowed with self-renewal, tumorigenicity, pluripotency, chemoresistance, differentiation, invasive ability, and plasticity, reside in specialized tumor niches and are responsible for tumor maintenance, metastasis, therapy resistance, and tumor relapse. The new-age "hierarchical or CSC" model of tumor heterogeneity is based on the concept of eradicating CSCs to prevent tumor relapse and therapy resistance. Small-molecular entities and biologics acting on various stemness signaling pathways, surface markers, efflux transporters, or components of complex tumor microenvironment are under intense investigation as potential anti-CSC agents. In addition, smart nanotherapeutic tools have proved their utility in achieving CSC targeting. Several CSC inhibitors in clinical development have shown promise, either as mono- or combination therapy, in refractory and difficult-to-treat cancers. Clinical investigations with CSC marker follow-up as a measure of clinical efficacy are needed to turn the "hype" into the "hope" these new-age oncology therapeutics have to offer.

Industry experiences with immune-mediated findings in biotherapeutic nonclinical toxicology studies

With the growth of monoclonal antibodies and other proteins as major modalities in the pharmaceutical industry, there has been an increase in pharmacology and toxicity testing of biotherapeutics in animals. Animals frequently mount an immune response to human therapeutic proteins. This can result in asymptomatic anti-drug antibody formation, immune complexes that affect drug disposition and/or organ function such as kidney, cytokine release responses, fatal hypersensitivity, or a range of reactions in between. In addition, an increasing number of oncology therapeutics are being developed that enhance or directly stimulate immune responses by a variety of mechanisms, which could increase the risk of autoreactivity and an autoimmune-like syndrome in animals and humans. When evaluating the risk of biotherapeutics prior to entering the clinic, the nonclinical safety data may include any of these responses and it is critical to understand whether they represent a safety liability for humans. The DruSafe Leadership group of the IQ Consortium conducted a survey of industry to understand sponsors' experiences with these immune reactions in nonclinical studies related to both immunogenicity and pharmacologically-mediated immune perturbations. The survey covered what pathways were affected, how the immune responses were presented, how the company and health authorities interpreted the data and whether the immune responses were observed in the clinic. Additionally, the survey gathered information on association of these findings with anti-drug antibodies as well as sponsor's use of immunogenicity predictive tools. The data suggests that the ability of a biotherapeutic to activate the immune system, intended or not, plays a significant role on characteristics of the response and whether theys are translatable.

Cost savings of biosimilars in oncology: A single institution experience.

10 Background: Biosimilar medications have increasingly gained regulatory approvals in recent years. Numerous conditions in the fields of hematology, oncology, rheumatology, and endocrinology have a biosimilar treatment option available. Some biosimilar agents can be obtained at a significantly lower cost than reference medications. Methods: Intermountain Healthcare Oncology Pharmacy and Therapeutics (P&amp;T) committee manages and maintains the formulary of accepted drugs. The committee consists of pharmacists, medical oncologists and oncology nurses. Biosimilar medications were approved in place of reference medications for the following: pegfilgrastim, bevacizumab, trastuzumab, and rituximab. Results: Annually, we administer about 6,450 combined doses of pegfilgastrim, bevacizumab, trastuzumab, and rituximab. Assuming 70% conversion from the reference medication to biosimilar agent, transitioning from the above listed reference medications to biosimilar would save an estimated $6.3 million annually (Table). This includes a $1.75 million savings from transitioning to rituximab alone. In addition, transitioning trastuzumab from a single dose vial to multi-dose vials is estimated to save an addition $730,000. Conclusions: Biosimilar agents can reduce the cost of oncology care to patients treated at our institution. We are utilizing biosimilar agents as part of our ongoing mission to decrease the financial toxicity of treatment for patients with cancer. [Table: see text]

Evaluation of deacetylase inhibition in metaplastic breast carcinoma using multiple derivations of preclinical models of a new patient-derived tumor.

Metaplastic breast carcinoma (MBC) is a clinically aggressive and rare subtype of breast cancer, with similar features to basal-like breast cancers. Due to rapid growth rates and characteristic heterogeneity, MBC is often unresponsive to standard chemotherapies; and novel targeted therapeutic discovery is urgently needed. Histone deacetylase inhibitors (DACi) suppress tumor growth and metastasis through regulation of the epithelial-to-mesenchymal transition axis in various cancers, including basal-like breast cancers. We utilized a new MBC patient-derived xenograft (PDX) to examine the effect of DACi therapy on MBC. Cell morphology, cell cycle-associated gene expressions, transwell migration, and metastasis were evaluated in patient-derived cells and tumors after treatment with romidepsin and panobinostat. Derivations of our PDX model, including cells, spheres, organoids, explants, and in vivo implanted tumors were treated. Finally, we tested the effects of combining DACi with approved chemotherapeutics on relative cell biomass. DACi significantly suppressed the total number of lung metastasis in vivo using our PDX model, suggesting a role for DACi in preventing circulating tumor cells from seeding distal tissue sites. These data were supported by our findings that DACi reduced cell migration, populations, and expression of mesenchymal-associated genes. While DACi treatment did affect cell cycle-regulating genes in vitro, tumor growth was not affected compared to controls. Importantly, gene expression results varied depending on the cellular or tumor system used, emphasizing the importance of using multiple derivations of cancer models in preclinical therapeutic discovery research. Furthermore, DACi sensitized and produced a synergistic effect with approved oncology therapeutics on inherently resistant MBC. This study introduced a role for DACi in suppressing the migratory and mesenchymal phenotype of MBC cells through regulation of the epithelial-mesenchymal transition axis and suppression of the CTC population. Preliminary evidence that DACi treatment in combination with MEK1/2 inhibitors exerts a synergistic effect on MBC cells was also demonstrated.

Predictive molecular pathology in non-small cell lung cancer in France: The past, the present and the perspectives.

The advent of molecular targets for novel therapeutics in oncology, notably for non-small cell lung carcinoma (NSCLC), led the French National Cancer Institute (INCa) to establish a national network of 28 hospital Molecular Genetics Centers for Cancer (MGCC) in 2007. In each University in France, laboratories were established to develop molecular biology testing to evaluate a few genomic alterations, initially a selection of genes, by using specific targeted polymerase chain reaction (PCR) assays. In a second phase, the number of studied genes was increased. In 2015, the MGCC benefited from an additional dedicated budget from the INCa to develop next-generation sequencing (NGS) technology. In the meantime, a new financial regulation for innovative testing has been established for the acts out of nomenclature. Consequently, all private and public laboratories in France have access to funding for molecular biology testing in oncology. The gene-based PCR assays or NGS tests have benefitted from reimbursement of cost testing by the INCa. Today, the laboratories consider this reimbursement to be only partial, and its use to be complex. In 2018, a strategic plan for medical genomic analyses (France Médecine Génomique 2025) was implemented to introduce more systematic sequencing into the health care pathway and oncology practice. The large panel of molecular tests should be centralized to a limited number of molecular genetic centers. This review describes the evolution of the different stages of implementation of molecular pathology testing for NSCLC patients over the last few years in France.

Management of metabolic adverse events of targeted therapies and immune checkpoint inhibitors in cancer patients: an Associazione Italiana Oncologia Medica (AIOM)/Associazione Medici Diabetologi (AMD)/Società Italiana Farmacologia (SIF) multidisciplinary consensus position paper.

The growing insights in the next-generation immunotherapy and the state-of-the-art advancement in targeted-agents significantly improved clinical outcome of cancer patients by pointing towards a unexplored Achilles' heel. Novel toxicity profiles have been uncovered, representing unmet medical needs. Thus, a panel of expert provide comprehensive pharmacological and clinical evidence, to provide a patient-tailored approach to metabolic adverse events associated with novel anti-cancer treatments. Prompted by the need of a multidisciplinary cooperation, a working group of Associazione Italiana Oncologia Medica (AIOM), Associazione Medici Diabetologi (AMD) and Società Italiana Farmacologia (SIF) examined the available literature data. The identification of patient risk profile and the characterization of metabolic effects of novel anti-tumour drugs is clearly a clinical challenge that can be addressed by a multidisciplinary clinical approach. Therefore, this review pinpoints the relevance of the challenging profiling of the patient suffering from dysmetabolic conditions induced by the novel therapeutics in medical oncology.

Oncology Therapeutics Targeting the Metabolism of Amino Acids.

Amino acid metabolism promotes cancer cell proliferation and survival by supporting building block synthesis, producing reducing agents to mitigate oxidative stress, and generating immunosuppressive metabolites for immune evasion. Malignant cells rewire amino acid metabolism to maximize their access to nutrients. Amino acid transporter expression is upregulated to acquire amino acids from the extracellular environment. Under nutrient depleted conditions, macropinocytosis can be activated where proteins from the extracellular environment are engulfed and degraded into the constituent amino acids. The demand for non-essential amino acids (NEAAs) can be met through de novo synthesis pathways. Cancer cells can alter various signaling pathways to boost amino acid usage for the generation of nucleotides, reactive oxygen species (ROS) scavenging molecules, and oncometabolites. The importance of amino acid metabolism in cancer proliferation makes it a potential target for therapeutic intervention, including via small molecules and antibodies. In this review, we will delineate the targets related to amino acid metabolism and promising therapeutic approaches.

Abstract 6121: Using the chicken chorioallantoic membrane in vivo model to study metastatic kidney cancer: A novel drug screening approach with more sustainable patient-derived xenografts

Abstract Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancers. Annually, 74,000 Americans are newly diagnosed with the disease, and more than 14,000 patients succumb to death, especially due to the advanced-stage ccRCC developing distant metastases. Unfortunately, there is currently no effective therapy for the deadly stage. Despite the recent progress in immunotherapy or anti-angiogenesis kinase inhibitors, the efficacy varies from one patient to another. Therefore, gaining further insight into the metastatic mechanism and establishing more effective and personalized treatments are of an urgent need to overcome the deadly outcome of metastatic ccRCC. Patient-derived xenografts (PDXs) have been a great resource to study clinical cases for oncologic pathways and therapeutics. However, the cost and time to establish PDXs in immunocompromised mice, such as SCID mice, have been significant burdens. Here, we propose an alternative PDX in the chicken chorioallantoic membrane (CAM) model. This model has a short incubation time, an inherently immunodeficient state, direct tumor visibility, and is both cost and labor efficient in comparison to the traditional mouse model. In the pursuit to streamline the in vivo cancer research and drug development, we explored the feasibility of the CAM PDXs of metastatic ccRCC. First, we sought to develop an optimized protocol for engrafting ccRCC from patients into the CAM model. Patient specimens were implanted either as primary tumor cells or small pieces of tumor chunks. The rate of successful PDXs engraftment was incredibly high, at 70% or above. Our preliminary data using the established cancer cell lines validated the CAM model's ability to recapitulate the tumor biology, including the growth and metastasis, of both mouse and human cell lines. By implanting cells stably transduced with Firefly luciferase, bioluminescence imaging can be used for sensitive detection of tumor growth on the membrane. FDG-PET can also be performed, showing promises of the model for further implementation of imaging and therapeutics. Taken together, the CAM model serves as a valuable platform of novel PDXs to accelerate the study of tumor biology and the development of individualized medicine. Many of the advantages of this model, however, could potentially also be limitations. For example, the short incubation time and immunodeficient state complicate the observation and interpretation of therapeutic effects. To overcome these limitations and make the model more clinically relevant, we are trying to propagate PDXs over multiple generations of CAM, as well as to incorporate autologous immune cells from patients. With these flexible modifications, the CAM PDXs could be even more promising to advance personalized medicine and improve the adverse prognosis of metastatic ccRCC. Citation Format: Moe Ishihara, Junhui Hu, Celine Cano-Ruiz, Anthony Wong, Lily Wu. Using the chicken chorioallantoic membrane in vivo model to study metastatic kidney cancer: A novel drug screening approach with more sustainable patient-derived xenografts [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6121.

Abstract 494: Effect of Aloysia polystachya in cancer stem cells of colorectal cancer

Abstract Colorectal cancer (CRC) is one of the most commonly diagnosed cancers and the Cancer Stem Cells (CSC) are the responsible of CRC persistence. Aloysia polystachya (AP) is an aromatic native plant of Verbenaceae family which is widely distributed and consumed in infusions in subtropical regions of South America. Its effects include diuretic, sedative, antispasmodic activities. We have previously demonstrated that AP extract has a cytotoxic effect in several human tumor cell lines, including apoptosis. The aim of this work was to investigate the cytotoxic effects of AP in vitro and in vivo in a CRC model. Therefore, CRC cell lines CT26 (murine) and HCT116 (human), were stimulated with AP extract or vehicle, with or without 5-fluorouracyle (5-FURA) and the survival and CSC properties were determined. The survival was measured after crystal violet staining at 570nm and CSC phenotype was determined by measuring the plurytpotency markers (CD133, OCT4 and Nanog by PCR and IFI), colony formation by clonogenic assay and HOESCHT efflux capacity (chemotherapeutic drugs efflux via ABCG2-transporters). In vivo experiments involved male BALB/c mice that were subcutaneously inoculated with murine CRC CT26 cell line. Once the tumor was detected, animals were treated twice a week (days 14, 17, 21, 24 and 28) with an intraperitoneal injection with AP and the sub-effective dose of 5-FURA (5mg/kg). Normal animals, not inoculated with CT26 cells were also used as control for histological analysis.The tumor size was determined twice a week. After 30 days, the mice were sacrificed and necropsied and the histopathology of tumors and the liver sections was performed by staining with hematoxylin and eosin. We found that AP extract decreased significantly the expression level of pluripotency markers, the colony formation and the efflux capacity of chemotherapeutic drugs respect to control cells and increased the cell death induced by 5-FURA treatment respect to cells stimulated with 5-FURA alone (P&amp;lt;0.05; Tukey test). We found that tumor growth was significantly inhibited by AP or AP plus 5-FURA respect to control animals without treatment or treated with 5-FURA alone (p&amp;lt;0.05; Tukey test). Histopathological analysis of tumor sections shown some necrosis area only in animals treated with AP or AP plus 5-FURA while the hepatic parenchyma shown a preserved architecture, confirming non-toxic effects of AP in vivo. Our results demonstrate that AP is capable to induce the cell death of CRC, resulted effective in vivo, non-toxic and has the ability to reduce the CSC side population. Being CSC the most resistant to chemotherapeutic drugs, responsible of cancer progression and perpetuation, the autochthonous plant derivatives could be attractive tools to be investigated as future oncologic therapeutics. Citation Format: Mileni Soares-Machado, Alejandra Palma, Laura Panelo, Leonardo Paz, Francisco Rosa, Cecilia Lira, Pablo Azurmendi, Fernanda Rubio, Guido Lenz, Alejandro Urtreger, Monica Costas. Effect of Aloysia polystachya in cancer stem cells of colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 494.