Significant Increase In Survival Research Articles

CD137 and PD-L1 targeting with immunovirotherapy induces a potent and durable antitumor immune response in glioblastoma models

BackgroundGlioblastoma (GBM) is a devastating primary brain tumor with a highly immunosuppressive tumor microenvironment, and treatment with oncolytic viruses (OVs) has emerged as a promising strategy for these tumors. Our...

Abstract 1586: Oncolytic virus HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 promotes systemic anti-tumor responses and cooperates with immuno-modulatory agents in multiple mouse syngeneic tumor models

Abstract Oncolytic virotherapy is an emerging treatment modality that may hold promise as a therapeutic option for cancer patients who do not respond to checkpoint inhibitors. Oncolytic viruses preferentially replicate in tumor cells, offer the ability to express transgenes and have been shown to modify the local and distant tumor microenvironments from immunosuppressive to immunostimulatory. We generated HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12, an oncolytic virus based on a modified herpes simplex virus type 1 (HSV-1) designed to selectively replicate in tumors and produce murine FMS-like tyrosine kinase 3 ligand (mFLT3L) to enhance dendritic cell expansion and T cell priming, and murine interleukin-12 (mIL12) to potentiate type I helper and cytotoxic T cell responses. We confirmed the expression and bioactivity of mFLT3L and mIL12 in vitro and evaluated the efficacy of HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 alone and in combination with anti-PD-1 or anti-4-1BB treatment in multiple syngeneic mouse tumor models. Bilateral tumor models were used and only one tumor was treated via intratumoral injection with HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12. Anti-tumor responses were evaluated in the injected tumor (local response), the uninjected tumor (abscopal) and via splenic immune profiling (systemic). HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 treatment alone led to tumor growth inhibition in both treated and contralateral tumors, and a significant increase in overall survival in the A20, Neuro2a and MC38 models. HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 in combination with anti-PD-1 blocking antibody further improved tumor growth inhibition in both treated and contralateral tumors in the MC38 syngeneic model, and significantly increased median overall survival compared to either agent as a monotherapy. In addition, HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 in combination with an agonistic antibody targeting 4-1BB significantly increased overall survival compared to either agent as a monotherapy in the MC38 model. To understand antigen-specific anti-tumor T cell responses, MC38 tumor antigen epitopes were identified by combining exome sequencing and MHC/HLA-binding prediction algorithms. Antigen-specific T cell responses were measured in an IFN-γ ELISPOT assay using splenocytes from treated mice. HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 induced and/or enhanced systemic T cell responses directed against both tumor neoantigens and tumor-associated antigens. Together, these data reveal that treatment with HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 can cause direct tumor lysis and induce an adaptive, systemic T cell-mediated anti-tumor immune response that can be further enhanced by concurrent PD-1 blockade or 4-1BB agonism in multiple syngeneic mouse tumor models. Citation Format: Keegan Cooke, Walter H. Meisen, Petia Mitchell, Juan Estrada, Jinghui Zhan, Jessica Orf, Peng Li, Christina de Zafra, Jing Qing, Jason DeVoss. Oncolytic virus HSV-1/ICP34.5-/ICP47-/mFLT3L/mIL12 promotes systemic anti-tumor responses and cooperates with immuno-modulatory agents in multiple mouse syngeneic tumor models [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 1586.

The Transition to Microsurgical Technique for Hepatic Artery Reconstruction in Pediatric Liver Transplantation.

Hepatic artery thrombosis represents a potentially fatal complication following liver transplantation. Rates of hepatic artery thrombosis are significantly higher in children, with mortality reported up to 80 percent. Microsurgical anastomosis has been shown to decrease the rate of hepatic artery thrombosis and now represents the standard of care at the authors' institution. In this article, the authors present the largest study of its type directly comparing rates of hepatic artery thrombosis with and without microsurgical reconstruction of the hepatic artery. All pediatric patients who underwent primary orthotopic liver transplantation between 1989 and 2018 were included. Patients were divided into two cohorts: standard anastomosis with loupes, and microsurgical anastomosis under the operating microscope. The authors' primary outcome was the rate of hepatic artery thrombosis. Secondary outcomes were graft survival, patient survival, retransplantation rate, requirement for intraoperative blood products, and length of stay. Two hundred thirty-one children met criteria for inclusion. One hundred eighty cases were performed with loupe magnification and 51 cases were performed under the microscope. The hepatic artery thrombosis rate was lower, but not significantly so (p = 0.114), in the microsurgical group [n = 1 (2.0 percent)] compared with the standard cohort [n = 15 (8.3 percent)]. Survival analysis revealed a significant increase in graft survival with microsurgical anastomosis (p = 0.020), but not patient survival (p = 0.196). The retransplantation rate was significantly lower with microsurgical anastomosis (p = 0.021). Microsurgical anastomosis was associated with a clinically important decrease in hepatic artery thrombosis compared with standard loupe anastomosis. The graft survival rate was significantly higher in the microsurgical cohort, with a reduced retransplantation rate at 1 year. On this basis, the authors recommend microsurgical hepatic artery anastomosis in cases of pediatric liver transplantation. . Therapeutic, III.

Pharmacological Inhibition of Luteinizing Hormone Signaling Promotes HSC Quiescence and Hematopoietic Regeneration

During hematopoiesis there is a balance between divergent functions such as self-renewal, differentiation, and proliferation. This process allows for continued blood formation throughout life as well as hematopoietic regeneration after periods of stress. It was recently shown that suppression of sex steroids, in addition to promoting T and B cell lymphopoiesis, promotes hematopoietic rejuvenation by mediating functional changes to HSC pool (Khong et al., 2015).Although those changes suggested a direct impact of testosterone on HSC function, when we examined the expression of hormone receptors on the hematopoietic compartment, we found almost no detectable expression of the androgen receptor. In contrast, expression of luteinizing hormone (LHR) was highly enriched on HSCs with nearly absent expression in downstream hematopoietic progenitor cells as well as in the stromal cell compartment. Consistent with the mouse data, high expression of LHR was also found in human HSCs (Fig. 1A). Given the peculiar expression of the LHR on HSCs, we sought to examine the direct effect of LH on HSC function. LH significantly enhanced mouse HSC colony formation in cobblestone area-forming cell and colony-forming cell assays. In addition, LH significantly expand human HSCs in a stroma-free culture system, without impacting on their colony-forming potential (Fig. 1B).Given the direct effects of LH on HSCs, we investigated if blocking LH could attenuate HSC proliferation in two different models of hematopoietic stress that force HSCs out of their quiescent status. Pharmacological suppression of LH using a luteinizing hormone-releasing hormone-antagonist (LHRH-Ant) inhibits HSCs from entry into cell cycle after Poly I:C and sub-lethal dose of total body irradiation (SL-TBI) exposure. Importantly, LH inhibition also significantly improved the proportion of live HSCs after SL-TBI (Fig. 1C). To gain some insights into the direct impact of LH on HSCs, we generated a hematopoietic chimera using KiLHRD582G mice, which have a constitutively-active D582G mutation in the Lhr gene. While there was no difference in primary reconstitution in mice receiving WT or KiLHRD582G HSCs, we found that mice reconstituted with KiLHRD582G and subsequently exposed to SL-TBI showed significantly higher proportion of apoptotic HSC compared to mice reconstituted with WT HSCs (Fig. 1D). To elucidate the molecular changes induced by LH inhibition, we assessed the expression of genes associated with quiescence, proliferation, DNA damage and apoptosis in HSC after SL-TBI. We found that LH suppression promoted higher levels of Hes1, Cdkn1a (p21), Bcl2 and Mcl1, genes previously identified to enforce HSC quiescence and survival (Fig. 1E). Consistent with these data, mice treated with the LHRH-Ant showed improved survival when exposed to successive doses of 5-fluorouracil, a well-established method to challenge HSC quiescence and self-renewal potential. It has been previously showing that promoting quiescence early after hematopoietic insults can mitigate HSC exhaustion and, ultimately, promote hematopoietic recovery and mouse survival. Mice receiving LHRH-Ant 24h after lethal TBI (840cGy) exposure showed a significant increase in survival compared to control animals. In fact, LH suppression spared LT-HSCs from radiation toxicity thus promoting hematopoietic recovery (Fig. 1F). Consistent with a negative role of LH on HSC recovery after radiation, mice deficient for LHR had a statistically significant increase in survival when exposed to L-TBI compared to control littermate.In conclusion our studies demonstrate that LH can directly regulate HSC quiescence, and that LH inhibition with a LHRH-Ant can be used as a radiation mitigation strategy. [Display omitted] DisclosuresJenq:Seres: Research Funding. Kiem:Rocket Pharmaceuticals: Consultancy, Equity Ownership, Patents & Royalties, Research Funding. van den Brink:Seres: Research Funding; Jazz Pharmaceuticals: Consultancy; Therakos Institute: Other: Speaking engagement; PureTech Health: Consultancy.

Targeting Burkitt's Lymphoma Using Novel, Discrete Carbon Nanotubes

Burkitt's lymphoma is an incredibly aggressive B-cell derived non-Hodgkin lymphoma that is quickly fatal if left untreated. Doxorubicin (Doxo) provides one method of treatment for this cancer, but has numerous common side effects including significant weight loss, nausea, hair loss, bone marrow suppression, vomiting, rash, heart damage, allergic reaction, tissue damage at injection site, and treatment-related leukemia. Therefore, better therapies which deliver Doxo specifically to tumor cells hold great promise for a more effective therapy with reduced side-effect severity. Carbon nanotubes (CNTs) have long been of interest as drug delivery transporters because of their unique structure, high drug-binding surface area, and variety of customization options. Unfortunately, most CNTs have proven toxic during in vivo studies because of the presence of high residual contaminants and near-unavoidable aggregative properties. A novel form of clean, discrete CNT (dCNT) marketed as Medical Grade MOLECULAR REBAR® (MGMR®) lack the aggregative problems and high toxin levels of CNT before them and show promise as a drug delivery technology.We observed no toxicity of dCNTs in vitro across multiple cell types or in vivo in mice establishing a high MTD of at least 70 mg/kg by an i.v. route. Biodistribution studies of Lu-177 radioisotope labeled dCNTs (single tail vein injection into BALB/C female mice) demonstrated tolerability and clearance from various organs. Mice were sacrificed at 7 timepoints under 34d and many organs were analyzed for accumulation. The liver, spleen, and blood identified one route of clearance and distribution, but it was interesting to note that the bone retained ~10% of injected dCNTs at all time points, demonstrating potential for bone targeted therapies. Further targeting to the bone was possible by grafting commonly available bone chelators to the surface of the dCNT to create BT-dCNT as shown by significantly great adhesion (p<0.05) to ex vivo bone.Protocols were then developed to saturate the surface of the dCNT with therapeutic Active Pharmaceutical Ingredients (API) and then characterize their elution/release over time. We then optimized methods for drug-loading and observed a slow drug release profile for most drugs. Enhanced pharmacokinetic information was tested in cell culture and then confirmed by animal experimentation. In addition, cell penetration and delivery study of MGMR® in vitro showed that endocytosis is nontoxic and well tolerated and that small peptides can be delivered to cancer cells and retain their functionality. Zeta Potential measurements (-40 to -50 mV) and Dynamic Light Scattering validated the stability of different dCNTs over time.Lastly, in a Raji-Burkitt's lymphoma mouse model, we saw significant increases in survival, and decreases in tumor burden in mice treated with Doxo (free, in dCNTs, and in BT-dCNTs vs no drug control). SCID mice were inoculated via the tail vein with 2x105 Raji B. luc+ tumor cells and treated once a week with one of the following: Doxo (5 mg/kg), dCNTs (14.29 mg/kg), dCNTs (14.29 mg/kg) + Doxo (5 mg/kg), BT-dCNTs (14.29 mg/kg) + Doxo (5 mg/kg), or no treatment. Using whole body bioluminescence imaging (BLI), we saw that the groups receiving both the Doxo-loaded dCNTs and the Doxo-loaded BT-dCNTs had greatly reduced tumor burden over time compared to untreated groups, and a tumor burden similar to those that received free Doxo alone (Figure 1A). Both groups receiving Doxo-loaded dCNTs also showed increased survival compared to the Doxo alone group (Figure 1B). Importantly, the typical signs of Doxo toxicity in mice, characterized by rapid weight loss or drug-related mortality, were not seen in the groups that received Doxo-loaded CNTs (Figure 1C).In summary, dCNTs is a highly promising biomedical tool for drug delivery for clinical applications. Our dCNTs represent a promising platform for use in biomedical research as they have proven to be nontoxic, tunable, stable, and capable of drug delivery and organ-specific targeting. This novel technology gives great promise for the bone-targeting ability of novel carbon nanotubes in vivo as a bone-specific drug delivery mechanism for diseases that grow in bone or bone marrow specifically. [Display omitted] DisclosuresFalank:BioPact Ventures, LLC: Research Funding. Tassett:BioPact Ventures, LLC: Employment. Harris:BioPact Ventures, LLC: Research Funding. Farrell:BioPact Ventures, LLC: Research Funding. Everill:BioPact Ventures, LLC: Employment. Reagan:BioPact Ventures, LLC: Research Funding.

Interaction between FLT3 and CD99 in Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a hematological malignancy with a 5-yr survival rate of 27%. This indicates an urgent need to identify better therapies. We previously analyzed various gene expression data sets of normal hematopoietic vs AML cells and reported that CD99 is upregulated in AML. CD99 loss of function by siRNA or monoclonal antibody decreased proliferation and migration of AML cells (Vaikari et al, ASH abstract, 2016). These results were consistent with Chung et al, recent study that demonstrated the therapeutic potential of targeting CD99 on disease stem cells in myeloid malignancies. However, the functional and mechanistic role of CD99 in AML and how it is upregulated remains unknown.To investigate the function of CD99 in AML, we transduced blasts obtained from patients with AML (N=3) and AML cell lines (THP-1 and U937) with CD99 overexpressing lentivirus. CD99 -lentiviral transduced primary blasts had a significant increase in cell number compared with control cells (day 5, 3.5-fold, p<0.001). Similarly, CD99 ectopic expression increased cell proliferation in THP-1 and U937 (1.83-fold, p<0.0001 and 1.85-fold, p<0.0001, respectively). Consistently, CD99 monoclonal antibody treatment (2.5ug/ml) induced cell differentiation in THP-1 cells, assessed by Wright-Giemse staining and by flow cytometry measurement of CD11b and enhanced apoptosis as measured by annexin and PI staining.We previously found that patients with FLT3 -ITD mutation exhibit higher levels of CD99 compared with patients with wild type FLT3 (FLT3 -WT). Here we hypothesize that FLT3 -ITD upregulates CD99 expression in AML and that both surface proteins cooperate to maintain leukemia stem cell survival. To test this hypothesis, we treated FLT3 -ITD positive cells (MV4-11 and MOLM-13) with 0.5uM of midostaurin (FLT3 inhibitor), and assessed CD99 expression levels. We found CD99 protein levels were significantly reduced following midostaurin treatment (>80%). On the other hand, CD99 knockdown resulted in increased FLT3- ITD protein levels in MV4-11 cells (FLT3- ITD homozygous). Furthermore, the combination of CD99 siRNA and midostaurin resulted in increased P- FLT3 and total FLT3 protein levels in MV4-11 cells compared to either treatment alone. We also co-expressed CD99 with FLT3-WT or FLT3-ITD in 293T cells and performed immunoprecipitation using CD99 pull down with flag tag. This assay demonstrated that CD99 bound to both FLT3 -WT and -ITD.Next, we characterized CD99 expression in patients with AML according to their clinical outcome. In 186 patients from The Cancer Genome Atlas (TCGA) AML dataset, CD99 was overexpressed in the favorable risk group as compared with the intermediate and poor-risk groups (p< 0.01, p<0.0001 respectively). To determine the clinical relevance of CD99 , patients were dichotomized into CD99 high and low based on CD99 median expression. The median overall survival (OS) of the CD99 high group was significantly longer than that of the CD99 low patients (OS, 27.4 vs 11.9 months, p=0.0063). Also, the median event-free survival (ES) of the CD99 high group were significantly longer compared with that of CD99 low patients (ES, 13.4 vs 8.9 months p=0.025). When patients were stratified into normal (CN) vs abnormal cytogenetic (Non-CN) AML, we found that, in CN-AML, the CD99 high group survived significantly longer than CD99 low patients (OS, 45.8 vs 12 months p=0.020). Similarly, there was a significant increase in the event free survival of CD99 high patients (ES, 19.3 vs 8.4 months p=0.026). There was no significant difference in CD99 expression between CN AML and non-CN AML. Furthermore, high CD99 was associated with longer overall (OS, 17.15 vs 7.7 months, p=0.0006) and event free survival (ES, 11.6 vs 5.65 months, p=0.001) in patients who did not receive hematopoietic stem cell transplant, but not in patients who received a transplant. In a multivariable analysis, CD99 high expression association with overall survival was not significant when adjusted by age, Cytogenetic Risk, Transplant status, DNMT3A, Tp53 and CD99 (p=0.364).In summary, although CD99 is a potential therapeutic target in AML, high CD99 is associated with better clinical outcome. Our study also demonstrates an interplay between CD99 and FLT3 , which may elucidate the upregulation of CD99 in patients with FLT3 -ITD. Further investigations are ongoing to determine the functional relevance of CD99 and FLT3 interaction. DisclosuresNo relevant conflicts of interest to declare.

Prognosis of functional mitral regurgitation after aortic valve replacement for pure severe aortic stenosis.

Whether patients with severe aortic stenosis (AS) and significant functional mitral regurgitation (MR) should undergo isolated aortic (aortic valve replacement [AVR]) or double aortic-mitral valve procedure (DVP) remains controversial. We sought to determine outcomes of such patients undergoing surgical (surgical aortic valve replacement [SAVR]) and transcatheter AVR (TAVR) or DVP, identify echocardiographic parameters predictive of significant residual MR after isolated AVR, and determine its impact on long-term survival. Data prospectively collected from 736 consecutive patients with severe AS and significant MR undergoing AVR or DVP were retrospectively analyzed. Exclusion of organic MR, other valve diseases and concomitant CABG yielded a final population of 74 patients with significant functional MR (32 TAVR, 23 SAVR, 19 DVP). Demographics, postoperative complications and age-adjusted survival were compared. Echocardiographic predictors of significant residual MR and its impact on survival were analyzed for patients undergoing isolated AVR. In the isolated AVR group, MR improvement occurred in 60% of patients and was associated with a significant increase in survival compared to persistence of significant MR (p = .03). Patients with improved MR had significantly greater preoperative left ventricular dilatation (LVEDD: 49 vs. 43 mm, p = .001; LVESD: 35 vs. 29 mm, p = .03; LVEDV: 101 vs. 71 ml, p = .0003; LVESV: 57 vs. 33 ml, p = .002). There was no significant difference in perioperative mortality (5.3 vs. 4.4 vs. 9.4%, p = .85) or age-adjusted long-term survival between isolated AVR and DVP groups (76.3 vs. 84.2% survival at 2-year follow-up, p = .26), or between SAVR, TAVR and DVP groups (78.2 vs. 75.0 vs. 84.2% survival at 2-year follow-up, p = .13). After isolated AVR, MR improvement occurs in 60% of patients. It is predicted by greater ventricular dimensions and associated with significantly better long-term survival. Whether a staged approach with transcatheter correction of MR should be considered in patients with significant residual MR following AVR remains undetermined.

The impact of expanding health insurance coverage for anti-cancer drugs on cancer survival in Korea.

BackgroundTo reduce out‐of‐pocket costs, the Korean government expanded health insurance reimbursement in anti‐cancer drugs for cancer patients in 2013. Our objective was to examine the impact of the benefit coverage expansion policy on healthcare utilization and overall survival (OS) among patients with six types of solid cancer after the policy of expanding health insurance coverage.MethodsThis study analyzed a before‐and‐after retrospective cohort of patients newly diagnosed with six types of solid cancer (stomach cancer, colorectal cancer, lung cancer, liver cancer, breast cancer, and prostate cancer) from January 1, 2009 to December 31, 2015 in Korea. The intervention was the expansion of reimbursement in 2013. Multivariate Cox proportional hazards regression was used to estimate the policy effect.ResultsIn total, 142,579 before and 147,760 patients after the benefit expansion, and after matched by age, gender, and stage, 132,440 before and 132,440 patients after policy were included in the analysis. Almost total medical expenditure increased for five types of cancer increased. The expansion of health insurance reimbursement was associated with significantly lower overall mortality compared with pre‐policy mortality for all six cancer sites.ConclusionThe policy of expanding health insurance reimbursement might have been associated with a significant increase in survival among cancer patients by ensuring access to health care and medicine. Although the reimbursement expansion timing differs for each cancer, it is believed that eliminating delayed treatment might rather lead to reduce medical expenses and improve health outcomes.

Paratransgenic manipulation of a tsetse microRNA alters the physiological homeostasis of the fly's midgut environment.

Tsetse flies are vectors of parasitic African trypanosomes, the etiological agents of human and animal African trypanosomoses. Current disease control methods include fly-repelling pesticides, fly trapping, and chemotherapeutic treatment of infected people and animals. Inhibiting tsetse's ability to transmit trypanosomes by strengthening the fly's natural barriers can serve as an alternative approach to reduce disease. The peritrophic matrix (PM) is a chitinous and proteinaceous barrier that lines the insect midgut and serves as a protective barrier that inhibits infection with pathogens. African trypanosomes must cross tsetse's PM in order to establish an infection in the fly, and PM structural integrity negatively correlates with trypanosome infection outcomes. Bloodstream form trypanosomes shed variant surface glycoproteins (VSG) into tsetse's gut lumen early during the infection establishment, and free VSG molecules are internalized by the fly's PM-producing cardia. This process results in a reduction in the expression of a tsetse microRNA (miR275) and a sequential molecular cascade that compromises PM integrity. miRNAs are small non-coding RNAs that are critical in regulating many physiological processes. In the present study, we investigated the role(s) of tsetse miR275 by developing a paratransgenic expression system that employs tsetse's facultative bacterial endosymbiont, Sodalis glossinidius, to express tandem antagomir-275 repeats (or miR275 sponges). This system induces a constitutive, 40% reduction in miR275 transcript abundance in the fly's midgut and results in obstructed blood digestion (gut weights increased by 52%), a significant increase (p-value < 0.0001) in fly survival following infection with an entomopathogenic bacteria, and a 78% increase in trypanosome infection prevalence. RNA sequencing of cardia and midgut tissues from paratransgenic tsetse confirmed that miR275 regulates processes related to the expression of PM-associated proteins and digestive enzymes as well as genes that encode abundant secretory proteins. Our study demonstrates that paratransgenesis can be employed to study microRNA regulated pathways in arthropods that house symbiotic bacteria.

The Effect of a Ketogenic Diet Concomitant With Chemotherapy in Pancreatic Ductal Adenocarcinoma Survival and Its Associated Cachexia

Abstract Objectives To evaluate the effect of a KD alone or in combination with the current chemotherapeutic drug gemcitabine (GEM) on morbidity and mortality in a clinically relevant genetically engineered LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) mouse model of PDA. Methods At three months old, KPC mice tumor size was measured by high-resolution ultrasound imaging of the pancreas. Male and female mice were allocated to either a control diet (CD; % kcal: 14% protein, 70% carb, 16% fat), a KD (%kcal: 14% protein, &amp;lt;1% carb, 85% fat), a CD + GEM, or a KD + GEM groups. GEM was administered at a dose of 100 mg/kg by i.p. injections 2x/wk for 7 times. Forelimb grip strength, body composition, and non-fasting glucose and ketone levels were evaluated at baseline, monthly and at time of sacrifice. Mice were euthanized upon reaching an endpoint criteria, which included ascites, weight loss &amp;gt; 20%, and/or extreme lethargy. Blood was drawn via cardiac puncture. Tissues were dissected and stored for further analysis. Results KPC mice fed a KD plus GEM exhibited a significant increase in median survival when compared to those fed CD alone. Only KPC mice fed a KD plus gemcitabine exhibited a significant increase in median survival compared to KPC mice fed a CD. KPC mice fed a CD, either alone or in combination with chemotherapy, showed a time-dependent decline in muscle strength by 2 months of intervention. In contrast, KPC mice fed a KD, either alone or combined with chemotherapy, significantly maintained muscle strength after 2 months. To elucidate potential mechanisms underlying the beneficial effects of a KD in maintaining muscle strength, we initially examined, in gastrocnemius muscle, the activation state of mTOR signaling. The phosphorylated levels of S6 ribosomal protein (p-S6), a downstream target of mTOR, were increased in gastrocnemius isolated from KPC mice fed a KD, compared to CD-fed mice. Conclusions Our findings indicate that KD maximizes and preserves motor function strength during PDA progression and enhances median survival when combined with chemotherapy. Additional studies are underway to evaluate the mechanisms of how KD improves and preserves muscle strength in PDA. Funding Sources Research Support: Startup funds and a University of California Comprehensive Cancer Center award to GGM. NEC is supported with a fellowship from UC-MEXUS.

HGG-29. VENETOCLAX SYNERGIZES WITH RADIATION THERAPY FOR THE TREATMENT OF DIPG

Abstract Background and Rationale Diffuse intrinsic pontine glioma (DIPG) is one of the most aggressive pediatric brain tumors. Currently, the main treatment for DIPG is radiation and it’s only a palliative care, as the tumor eventually becomes resistant to radiation. In this study we found that radiation leads to an increase in anti-apoptotic BH3 proteins mainly BCL2 in DIPG. Previous studies in other tumor types have shown that increase in these pro-survival BCL2 family members are associated with treatment resistance and poor prognosis. Therefore, we hypothesize that inhibition of BCL2 using a small-molecule inhibitor, venetoclax that crosses the blood-brain barrier, will represent a possible therapeutic strategy to overcome radiation resistance in DIPG. Approach: For in vitro studies, DIPG cells were exposed to different radiation doses (0–10 Gy) and the magnitude of the sensitizing effect of venetoclax (with IC15) was calculated by clonogenic assay. Evaluated BCL2 family proteins by western and cytotoxicity by cleaved caspase incucyte assays. For in vivo studies, NSG mice orthotopically engrafted with a human H3K27M-DIPG luciferase-expressing cells in the pons were exposed to a focal fractionated radiation of 2Gy/day for 3 days. Mice were randomized into 2 groups based on bioluminescence IVIS signal intensity; each group receiving either venetoclax (15 mg/kg, by i.p) 3 days/week for 10 weeks or vehicle. Decrease in tumor burden was measured by IVIS and survival was evaluated compared to vehicle treated mice. Results Single agent venetoclax showed no significant activity against DIPG tumors in in vitro and in vivo DIPG xenografts. Single-agent radiation cleared the tumor burden but only transiently. Combination of radiation with venetoclax showed considerable synergistic anti-tumor effect in vitro and in vivo leading to a significant increase in animal survival beyond either single agent treatments. The metabolic reprogramming that results in this enhanced cell-killing effect will be discussed.

MO667SWITCHING TO ONE-TIME USE OF DIALYZERS FOR HEMODIALYSIS: A ONE-YEAR SURVIVAL ANALYSIS IN TASHKENT

Abstract Background and Aims Until recently, for various reasons in Uzbekistan, it was often necessary to reuse disposable dialyzers for hemodialysis procedures. On June 13, 2018, a Resolution of the President of the Republic of Uzbekistan was issued on measures to improve the effectiveness of the provision of nephrological and dialysis care to the population of our country. Thanks to this, funding and provision of all nephrological and dialysis centers have sharply increased, as well as the country's transplant service has been re-established. Since the end of 2018, dialyzers are used exclusively once in all dialysis centers in our country. We were interested in comparatively studying the survival rate of dialysis patients during one year, before and after the transition to the use of single dialyzers in our center. Method We conducted a prospective observation of 120 (63 men and 57 women) patients with end-stage CKD and receiving programmed hemodialysis at our dialysis center in Tashkent. Our observation took place for 2 years: from the beginning of 2018 to the end of 2019. The study took place in 2 stages, 1 year each: at the first stage, within 1 year (from the beginning to the end of 2018), the survival rate of the observed patients receiving hemodialysis with repeated use of disposable dialyzers was assessed. At the second stage (after the transition to one-time use of dialyzers throughout the country), also for 1 year (from the beginning to the end of 2019), all the patients we observed received hemodialysis sessions with a single use of dialyzers. All patients were diagnosed with end-stage CKD. The average age of the patients was 49.7 ± 14.1 years. The average duration of hemodialysis was 29.4 (6-252) months. All patients underwent hemodialysis sessions with identical apparatus and dialyzers of the same manufacturer. The primary diseases in the patients were glomerulonephritis (n = 44, 36.7%), type 2 diabetes (n = 38, 31.7%), urolithiasis (n = 13, 10.8%), polycystic kidney disease (n = 7, 5.8%), lupus (n = 5, 4.2%) and others (n = 13, 10.8%). Survival was assessed using the Kaplan-Meier method, the confidence interval was determined by Greenwood. Results During the entire period (24 months) of observation, out of 120 patients, 26.7% (n = 32) patients died, 73.3% (n = 88) survived (of which 10 patients underwent kidney transplantation). We will assess the survival rate depending on the periods of dialyzer use. During 1 year of follow-up (the period of repeated use of disposable dialyzers), 19.2% (n = 23) patients died, 80.8% (n = 97) survived and continued to receive hemodialysis, of which 2 (1.7%) patients underwent a kidney transplant and knocked out of observation. The main cause of death was cardiovascular complications (sudden cardiac death, myocardial infarction, stroke, etc.), as a result of which 69.6% (n = 16) of patients died. The survival rate for 1 year was S (t) = 0.815 [95% CI, 0.745-0.885]. Over the next 12 months (single use period), out of 95 patients continuing to receive hemodialysis, 9.5% (n = 9) patients died, 82.1% (n = 78) patients survived. 8.4% (n = 8) of the observed patients underwent kidney transplantation. 55.6% (n = 5) of all deceased patients died from cardiovascular complications. The survival rate at 1 year was S (t) = 0.901 [95% CI, 0.839-0.962]. Conclusion Compliance with the standards for hemodialysis, in particular, the single use of disposable dialyzers for hemodialysis sessions leads to a decrease in the lethality of dialysis patients. The transition from multiple to single use of disposable dialyzers in one dialysis center in Uzbekistan showed a significant increase in survival by 10.6%.

Иммунотерапия метастатической меланомы вчера, сегодня, завтра

For a long time, the main drug for the treatment of patients with metastatic melanoma remained dacarbazine, approved by the US Food and Drug Administration in 1975. This method of treatment could hardly guarantee the significant increase in overall survival. Taking in account the high immunogenicity of melanoma, back in the XIX and XX centuries, scientists began to develop immuno-oncological drugs aimed at activating antitumor immunity. Many studies were conducted before the goal was achieved. So in the arsenal of an oncologist there appeared check-point inhibitors – which are in fact the most effective method of treating melanoma, which radically changed the prognosis of the disease.

Colecistectomía y trasplante cardíaco

Background:The advances in perioperative care and immunosuppressive treatment resulted in a significant increase in survival of transplant patients; as a result, cholelithiasis is more common in transplant patients.Objective: The aim of this study is to analyze and describe the results obtained in cholecystectomies in heart transplant patients.Material and methods: We selected patients by cross-referencing the databases of heart transplantation and scheduled biliary surgeries, and collected information on their medical history, clinical parameters and laboratory tests, among other data.Results: Between January 1994 and December 2017, 154 heart transplant procedures were performed; mean age was 40 years; 16 underwent laparoscopic cholecystectomy after heart transplantation and were included in this study. There were no complications, readmissions or deaths.Conclusion: Laparoscopic cholecystectomy is safe and is the method of choice for heart transplant patients with cholelithiasis. Intraoperative cholangiography should be performed as the predictors of choledocholithiasis are usually abnormal.

Early mortality in metastatic cancer: A SEER population data analysis.

e18789 Background: Overall survival from cancer has continuously improved over the last thirty years. This is due, in part, to advances in systemic treatment of some cancers resulting in clinically significant increases in long-term survival. Despite these improvements in long-term survival, many patients die quickly after a diagnosis of metastatic cancer, possibly being denied the opportunity to benefit from these recent advances in cancer treatment. To identify the scope and predictors of early mortality in de novo metastatic cancer, we analyzed population-based data, focusing on patients with early mortality. Methods: Using the Survival, Epidemiology and End Results (SEER) Database we analyzed adult patients who presented with de-novo metastatic solid malignancies diagnosed between 2008-2016. We defined early mortality as 1- and 2-month mortality. Factors associated with early mortality were analyzed including primary site of cancer and demographics. Correlations between categorical variables were analyzed with chi squared tests and survival data was derived from life tables using STATA I/C 12.1. Results: Of 519,553 patients identified, 273,976 (53%) were males, 411,041 (79%) were white, 213,325 (41%) had lung cancer, 65,679 (13%) colorectal cancer and 49,139 (10%) pancreatic cancer. One - and two - month cancer specific mortality was 12.4% and 22.5% respectively for the entire cohort. Mortality from cancer in the first two months after diagnosis decreased only marginally between 2008 and 2016 (23.4% and 21.6 %, respectively). Cancers with the highest 2-month cancer specific mortality rates were liver (39.5%), pancreatic (36.3%), lung (26.8%), gastroesophageal (23.7%), and urothelial (21.2%). Cancers with the lowest 2-month mortality rate were breast (10.4%) and prostate cancer (5%). Patients who presented with liver metastases had a clinically significant higher 2- month cancer specific mortality rate (29% vs. 18% p &lt; 0.001), brain metastases were associated with a milder increase in 2-month cancer specific mortality (25%vs 21% p &lt; 0.001) and bone metastases were not associated with a clinically significant difference in 2-month cancer specific mortality (22% vs 21%, p = 0.047). Other factors associated with early mortality included increasing age, low income, and living in a rural area. Conclusions: Over 21% of newly diagnosed metastatic cancer patients die within 2 months of their diagnosis, with little improvement over the last decade, rendering this an urgent unmet need in cancer care. Further research is urgently required to better identify the causative and treatable factors of early mortality in cancer patients.

Resveratrol significantly improves cell survival in comparison to dexrazoxane and carvedilol in a h9c2 model of doxorubicin induced cardiotoxicity

Cancer is one of the leading causes of deaths worldwide with 18.1 million deaths per year. Although there have been significant advances in anti-cancer therapies, they can often result in side effects with cardiovascular complications being the most severe. Dexrazoxane is the only currently approved treatment for prevention of anthracycline induced cardiotoxicity but there are concerns about its use due to the development of secondary malignancies and myelodysplastic syndrome. Additionally, it is only recommended in patients who are due to receive a total cumulative dose of 300 mg/m2 of doxorubicin or 540 mg/m2 of epirubicin. Thus, there exists an urgent need to develop new therapeutic strategies to counteract anthracycline induced cardiotoxicity. The h9c2 cardiomyoblast was investigated for its differentiation capacity and used to screen and compare promising prophylactics for doxorubicin induced cardiotoxicity. The half maximal inhibitory concentration of doxorubicin was determined in differentiated h9c2 cells after 24 h of exposure, to establish a model for drug screening. Cells were treated with dexrazoxane, resveratrol, and carvedilol either 3 h or 24 h prior to doxorubicin treatment. The ability of these cardioprotectants to prevent cardiotoxicity was analysed using the cck-8 cell viability assay and the dichlorofluorescin diacetate (DCFDA) reactive oxygen species (ROS) assay. There was no significant increase in survival in treatment groups after 3 h, however, at 24 h, resveratrol significantly improved survival compared to all other groups (p < 0.05). Additionally, dexrazoxane and resveratrol significantly decreased ROS formation at 3 h (p < 0.05) and all groups significantly decreased ROS production at 24 h (p < 0.001). This work is the first comparison of these cardioprotectants and suggests that resveratrol may be a more effective treatment in the prevention of anthracycline induced cardiotoxicity, compared to dexrazoxane and carvedilol. However, further work will be needed in order to decipher the exact mechanism and potential of this drug in the clinic.

Multi-epitope DnaK peptide vaccine accords protection against lethal S. typhimurium challenge: Elicits both cell mediated immunity and long-lasting serum-neutralizing antibody titers

Typhoid vaccine development has been impeded by inability of currently available vaccines to induce cellular immunity along with neutralizing antibodies against all serovars of S. Typhi and S. Paratyphi. Unfortunately, antibiotic treatment has shown to be an ineffective therapy due to development of resistance against multiple antibiotics. In the present study, we have explored the immunogenicity and protective efficacy of in-silico designed multi-epitope DnaK peptides as candidate vaccine molecules against Salmonella. Immunization studies in mouse typhoid model revealed three of these peptides (DP1, DP5 and DP7) are highly efficacious, stimulating both humoral and cell mediated immunity along with long lasting antibody memory response. There was significant increase in antibody titers (IgG, IgG1, IgG2a, IgA and IgM), lymphocyte proliferative responses and cytokine levels. Immunized groups showed marked reduction in organ bacterial load, fecal shedding and pronounced protection (upto 80%) as compared to unimmunized controls after challenge with S. typhimurium. Our results demonstrate the huge potential of DnaK peptide vaccine candidates (DP1, DP5 and DP7) to accord protective immunity with significant increase in survivability against Salmonella infection in mice, thus commending these molecules as promising agents to tackle typhoid.

Assessment of Immune Status in Dynamics for Patients with Cancer Undergoing Immunotherapy.

Immunotherapy using immune checkpoint inhibitors has revolutionized the treatment, and many types of cancer show a response rate of 20–40% and a significant increase in five-year survival. However, immunotherapy is expensive and may cause serious adverse events. Therefore, a predictive method allowing identification of responding patients before starting the treatment would be very useful. In this study, we aimed to identify and implement other individual prognosis factors, factors that could lead to an improved clinical decision made in regard to the patient to establish an individualized treatment. Materials and Methods. All patients recruited from October 2018 to July 2019 were treated in OncoFort Hospital, Bucharest, with nivolumab or pembrolizumab. We investigated T lymphocyte CD3+, CD4+, CD8+, and CD4/CD8 cells by flow cytometry in patients before and after receiving treatment with anti-PD-1 agents. Results. We found that the responder group showed higher expression on CD4+ cells than the nonresponder group after the first cycle of immunotherapy. The prediction of the immunotherapeutic effect revealed that the elevation of T lymphocytes CD8+ and CD4+ after the first cycle of immunotherapy was followed by a decrease in their expression after the second cycle and was followed by a return almost to that one after the first administration. Conclusion. Our work indicates that the evaluation of the cells of the immune system in relation to the tumor and immunotherapy may lead to a better understanding of the pathogenic mechanisms and the identification of prognostic and predictive factors that will more effectively model the therapeutic approach.

100P Efficacy of enobosarm, a selective androgen receptor (AR) targeting agent, in patients with metastatic AR+/ER+ breast cancer resistant to estrogen receptor targeted agents and CDK 4/6 inhibitor in a phase II clinical study

CDK 4/6 inhibitors (CDK4/6i) in combination with an ER targeted agent are the standard of care in in the treatment of metastatic ER+ breast cancer (MBC). Despite the significant increase in progression free survival seen with this combination, all patients eventually progress and therefore, there is a need for additional therapeutic options. The AR is expressed in up to 90% of ER+ breast cancer where it acts as a tumor suppressor. Enobosarm is a selective AR activating agent that does not cause virilization, and has positive clinical attributes such as promotion of bone strength and improvement of physical function.

Veliparib Is an Effective Radiosensitizing Agent in a Preclinical Model of Medulloblastoma.

Medulloblastoma is the most common malignant childhood brain tumor, and 5-year overall survival rates are as low as 40% depending on molecular subtype, with new therapies critically important. As radiotherapy and chemotherapy act through the induction of DNA damage, the sensitization of cancer cells through the inhibition of DNA damage repair pathways is a potential therapeutic strategy. The poly-(ADP-ribose) polymerase (PARP) inhibitor veliparib was assessed for its ability to augment the cellular response to radiation-induced DNA damage in human medulloblastoma cells. DNA repair following irradiation was assessed using the alkaline comet assay, with veliparib inhibiting the rate of DNA repair. Veliparib treatment also increased the number of γH2AX foci in cells treated with radiation, and analysis of downstream pathways indicated persistent activation of the DNA damage response pathway. Clonogenicity assays demonstrated that veliparib effectively inhibited the colony-forming capacity of medulloblastoma cells, both as a single agent and in combination with irradiation. These data were then validated in vivo using an orthotopic implant model of medulloblastoma. Mice harboring intracranial D425 medulloblastoma xenografts were treated with vehicle, veliparib, 18 Gy multifractionated craniospinal irradiation (CSI), or veliparib combined with 18 Gy CSI. Animals treated with combination therapy exhibited reduced tumor growth rates concomitant with increased intra-tumoral apoptosis observed by immunohistochemistry. Kaplan–Meier analyses revealed a statistically significant increase in survival with combination therapy compared to CSI alone. In summary, PARP inhibition enhanced radiation-induced cytotoxicity of medulloblastoma cells; thus, veliparib or other brain-penetrant PARP inhibitors are potential radiosensitizing agents for the treatment of medulloblastoma.