Docking-Based Virtual Screening Enables Prioritizing Protein Kinase Inhibitors With In Vitro Phenotypic Activity Against Schistosoma mansoni

Schistosomiasis is a parasitic neglected disease with praziquantel (PZQ) utilized as the main drug for treatment, despite its low effectiveness against early stages of the worm. To aid in the search for new drugs to tackle schistosomiasis, computer-aided drug design has been proved a helpful tool to enhance the search and initial identification of schistosomicidal compounds, allowing fast and cost-efficient progress in drug discovery. The combination of high-throughput in silico data followed by in vitro phenotypic screening assays allows the assessment of a vast library of compounds with the potential to inhibit a single or even several biological targets in a more time- and cost-saving manner. Here, we describe the molecular docking for in silico screening of predicted homology models of five protein kinases (JNK, p38, ERK1, ERK2, and FES) of Schistosoma mansoni against approximately 85,000 molecules from the Managed Chemical Compounds Collection (MCCC) of the University of Nottingham (UK). We selected 169 molecules predicted to bind to SmERK1, SmERK2, SmFES, SmJNK, and/or Smp38 for in vitro screening assays using schistosomula and adult worms. In total, 89 (52.6%) molecules were considered active in at least one of the assays. This approach shows a much higher efficiency when compared to using only traditional high-throughput in vitro screening assays, where initial positive hits are retrieved from testing thousands of molecules. Additionally, when we focused on compound promiscuity over selectivity, we were able to efficiently detect active compounds that are predicted to target all kinases at the same time. This approach reinforces the concept of polypharmacology aiming for “one drug-multiple targets”. Moreover, at least 17 active compounds presented satisfactory drug-like properties score when compared to PZQ, which allows for optimization before further in vivo screening assays. In conclusion, our data support the use of computer-aided drug design methodologies in conjunction with high-throughput screening approach.

P-P44 Clinical outcomes of consecutive patients undergoing distal pancreatectomy over the last decade at a high volume tertiary pancreatic surgery unit

Background

Distal pancreatectomy (DP) enables resection of lesions in the body and tail of the pancreas.  Over the past decade, the Laparoscopic approach has become frequently employed.  There remains scarce outcome data available following laparoscopic distal pancreatectomy over a long time period from high volume centres. Postoperative pancreatic fistula (POPF) remains the main source of morbidity and mortality after DP. The causes of POPF are multifactorial and poorly understood.  The optimal method of pancreatic stump closure is still debated with variation in clinical practice.

Methods

All patients that underwent distal pancreatectomy at a UK tertiary pancreatic surgery centre between January 2011 and January 2021 were identified and clinical outcomes examined. Patients undergoing completion pancreatectomies were excluded. Clinical, pathological and surgical data for the included patients was retrospectively collected from the electronic patient record.  Clinically significant POPF was defined as Grade B or C as per the ISGPF guidelines. For stapled stump closure, the Compression Index (CI) was calculated using closed staple height (mm) divided by the pancreatic thickness (mm). High and low CI was defined around the median.

Results

233 patients (n = 90 open and n = 143 laparoscopic) were included in the final analysis. The laparoscopic approach was associated with comparable morbidity and significantly lower blood loss, shorter operative time and shorter length of stay. There were no significant differences in age, sex, final histology, closure technique, or ASA Score of 3 or more amongst patients with clinically relevant POPF (CR-POPF). The POPF group had a significantly higher BMI, drain duration and readmission rate. CI data was available for 78 cases (range 0.04-0.21). There was no significant difference in low vs high CI for patients with CR-POPF.

Conclusions

Laparoscopic distal pancreatectomy is associated with favourable clinical outcomes in this series. Stapled vs sutured closure of the pancreatic stump offered equivocal outcomes with relation to POPF. POPF continues to have a significant impact on a clinical recovery as evident from longer drain duration and high readmission rates. Further research is required to try to establish methods for reducing the incidence of POPF after distal pancreatectomy.

JMM Profile: Carbapenems: a broad-spectrum antibiotic

Carbapenems are potent members of the β-lactam family that inhibit bacterial cell-wall biosynthesis inhibitors . They are highly effective against Gram-negative and Gram-positive drug-resistant infections . As such, carbapenems are typically reserved as an antibiotic of last resort. The WHO lists meropenem as an essential medicine. Nausea and vomiting are reported in ≤20% of carbapenem recipients, with 1.5% suffering seizures. Enzymatic hydrolysis of the β-lactam ring is the main driver of clinical resistance. These enzymes can be classified as Class A, B and D. Classes A and D are serine β-lactamases, whereas Class B rely on metal-mediated hydrolysis, typically through zinc.

Intraoperative radiotherapy for pancreatic cancer: implementation and initial experience

This article reports on the first series of patients to receive intraoperative radiotherapy for pancreatic cancer in the UK. The data suggest that this treatment modality is feasible and safe, laying a platform for collaborative multicentre trials to better assess efficacy.

Comparing practice and outcome of laparoscopic liver resection between high-volume expert centres and nationwide low-to-medium volume centres

BACKGROUND

Based on excellent outcomes from high-volume centres, laparoscopic liver resection is increasingly being adopted into nationwide practice which typically includes low-medium volume centres. It is unknown how the use and outcome of laparoscopic liver resection compare between high-volume centres and low-medium volume centres. This study aimed to compare use and outcome of laparoscopic liver resection in three leading European high-volume centres and nationwide practice in the Netherlands.

METHOD

An international, retrospective multicentre cohort study including data from three European high-volume centres (Oslo, Southampton and Milan) and all 20 centres in the Netherlands performing laparoscopic liver resection (low-medium volume practice) from January 2011 to December 2016. A high-volume centre is defined as a centre performing >50 laparoscopic liver resections per year. Patients were retrospectively stratified into low, moderate- and high-risk Southampton difficulty score groups.

RESULTS

A total of 2425 patients were included (1540 high-volume; 885 low-medium volume). The median annual proportion of laparoscopic liver resection was 42.9 per cent in high-volume centres and 7.2 per cent in low-medium volume centres. Patients in the high-volume centres had a lower conversion rate (7.4 versus 13.1 per cent; P < 0.001) with less intraoperative incidents (9.3 versus 14.6 per cent; P = 0.002) as compared to low-medium volume centres. Whereas postoperative morbidity and mortality rates were similar in the two groups, a lower reintervention rate (5.1 versus 7.2 per cent; P = 0.034) and a shorter postoperative hospital stay (3 versus 5 days; P < 0.001) were observed in the high-volume centres as compared to the low-medium volume centres. In each Southampton difficulty score group, the conversion rate was lower and hospital stay shorter in high-volume centres. The rate of intraoperative incidents did not differ in the low-risk group, whilst in the moderate-risk and high-risk groups this rate was lower in high-volume centres (absolute difference 6.7 and 14.2 per cent; all P < 0.004).

CONCLUSION

High-volume expert centres had a sixfold higher use of laparoscopic liver resection, less conversions, and shorter hospital stay, as compared to a nationwide low-medium volume practice. Stratification into Southampton difficulty score risk groups identified some differences but largely outcomes appeared better for high-volume centres in each risk group.

Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

Development and Interrogation of a Transcriptomic Resource for the Giant Triton Snail (Charonia tritonis)

Gastropod molluscs are among the most abundant species that inhabit coral reef ecosystems. Many are specialist predators, along with the giant triton snail Charonia tritonis (Linnaeus, 1758) whose diet consists of Acanthaster planci (crown-of-thorns starfish), a corallivore known to consume enormous quantities of reef-building coral. C. tritonis are considered vulnerable due to overexploitation, and a decline in their populations is believed to have contributed to recurring A. planci population outbreaks. Aquaculture is considered one approach that could help restore natural populations of C. tritonis and mitigate coral loss; however, numerous questions remain unanswered regarding their life cycle, including the molecular factors that regulate their reproduction and development. In this study, we have established a reference C. tritonis transcriptome derived from developmental stages (embryo and veliger) and adult tissues. This was used to identify genes associated with cell signalling, such as neuropeptides and G protein-coupled receptors (GPCRs), involved in endocrine and olfactory signalling. A comparison of developmental stages showed that several neuropeptide precursors are exclusively expressed in post-hatch veligers and functional analysis found that FFamide stimulated a significant (20.3%) increase in larval heart rate. GPCRs unique to veligers, and a diversity of rhodopsin-like GPCRs located within adult cephalic tentacles, all represent candidate olfactory receptors. In addition, the cytochrome P450 superfamily, which participates in the biosynthesis and degradation of steroid hormones and lipids, was also found to be expanded with at least 91 genes annotated, mostly in gill tissue. These findings further progress our understanding of C. tritonis with possible application in developing aquaculture methods.

Clinical relevant pancreatic fistula after pancreatoduodenectomy: when negative amylase levels tell the truth

Drain Amylase level are routinely determined to diagnose pancreatic fistula after Pancreatocoduodenectomy. Consensus is lacking regarding the cut-off value of amylase to diagnosis clinically relevant postoperative pancreatic fistulae (POPF). The present study proposes a model based on Amylase Value in the Drain (AVD) measured in the first three postoperative days to predict a POPF. Amylase cut-offs were selected from a previous published systematic review and the accuracy were validated in a multicentre database from 12 centres in 2 countries. The present study defined POPF the 2016 ISGPS criteria (3 times the upper limit of normal serum amylase). A learning machine method was used to correlate AVD with the diagnosis of POPF. Overall, 454 (27%) of 1638 patients developed POPF. Machine learning excluded a clinically relevant postoperative pancreatic fistulae with an AUC of 0.962 (95% CI 0.940-0.984) in the first five postoperative days. An AVD at a cut-off of 270 U/L in 2 days in the first three postoperative days excluded a POPF with an AUC of 0.869 (CI 0.81-0.90, p < 0.0001). A single AVD in the first three postoperative days may not exclude POPF after pancreatoduodenectomy. The levels should be monitored until day 3 and have two negative values before removing the drain. In the group with a positive level, the drain should be kept in and AVD monitored until postoperative day five.

1227. Plazomicin Susceptibility Testing using ETEST® MIC for Enterobacterales

Background

Plazomicin (PLZ) approved by FDA in June of 2018, is an aminoglycoside class antibacterial indicated for the treatment of adults with complicated urinary tract infections (cUTI) including pyelonephritis caused by Enterobacterales. It is used in patients who have limited or no alternative treatment options, e.g. CRE and MDRO patients. The drug has bactericidal activity, it is active against organisms producing ESBL, Carbapenemase and aminoglycoside-modifying enzymes. The purpose of this study was to compare ETEST® PLZ bioMérieux to the broth microdilution reference method (BMD) for Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Klebsiella oxytoca and pneumoniae, Morganella morganii, Providencia stuartii, Proteus mirabilis and vulgaris and Serratia marcescens isolates.

Methods

A total of 598 isolates were tested by ETEST® (PLZ) and BMD at four clinical trial sites.

Isolates were subcultured on tryptic soy or Columbia agar plates supplemented with 5% sheep blood. Suspensions of the isolates were prepared in 0.85% saline, which were used to inoculate BMD and Mueller Hinton agar for ETEST®. Results were read after 16-20 hours incubation at 35°C +2°C in ambient air. QC organisms were tested with each run following CLSI QC guidelines.

Results were analyzed using FDA breakpoints for PLZ (Susceptible &lt;2 µg/mL, Intermediate 4 µg/mL, Resistant &gt;8 µg/mL).

Performance was evaluated using FDA performance criteria, EA and CA (≥ 90%), major error rate (≤3.0%) and very major error rate (≤2.0%).

Results

Conclusion

ETEST® PLZ clinical performance met the FDA acceptance criteria and was found useful for determining Plazomicin MIC of Enterobacterales, including ESBL, CRE (MBL, KPC, Oxa-48), high level AmpC and aminoglycoside resistant strains. Percent susceptibility of Plazomicin is at 80% among the 598 isolates tested, the mode MIC is 0.5 ug/ml as Susceptible.

Disclosures

Tom Armstrong, BS, bioMérieux (Employee) Laurine Blanchard, PhD, bioMérieux (Employee) Michael Kresken, PhD, bioMérieux (Scientific Research Study Investigator, Research Grant or Support) Gilles Zambardi, biomerieux (Employee) Marion Pompilio, BioMérieux (Employee)

Appendicitis with direct fistulation into the liver: a forgotten cause of pyogenic liver abscess

Pyogenic liver abscess typically occurs secondary to biliary or haematogenous spread of organisms. In the context of acute appendicitis, abscesses generally occur due to haematogenous spread through the mesenteric vasculature. Historically, few cases of direct intra-abdominal spread have been reported but this has become vanishingly rare since the development of antibiotic therapy with no recorded cases in a search of over 900 cases in the literature.

Inhibition of Mycobacterium tuberculosis InhA: Design, synthesis and evaluation of new di-triclosan derivatives

Multi-drug resistant tuberculosis (MDR-TB) represents a growing problem for global healthcare systems. In addition to 1.3 million deaths in 2018, the World Health Organisation reported 484,000 new cases of MDR-TB. Isoniazid is a key anti-TB drug that inhibits InhA, a crucial enzyme in the cell wall biosynthesis pathway and identical in Mycobacterium tuberculosis and M. bovis. Isoniazid is a pro-drug which requires activation by the enzyme KatG, mutations in KatG prevent activation and confer INH-resistance. 'Direct inhibitors' of InhA are attractive as they would circumvent the main clinically observed resistance mechanisms. A library of new 1,5-triazoles, designed to mimic the structures of both triclosan molecules uniquely bound to InhA have been synthesised. The inhibitory activity of these compounds was evaluated using isolated enzyme assays with 2 (5-chloro-2-(4-(5-(((4-(4-chloro-2-hydroxyphenoxy)benzyl)oxy)methyl)-1H-1,2,3-triazol-1-yl)phenoxy)phenol) exhibiting an IC₅₀ of 5.6 µM. Whole-cell evaluation was also performed, with 11 (5-chloro-2-(4-(5-(((4-(cyclopropylmethoxy)benzyl)oxy)methyl)-1H-1,2,3-triazol-1-yl)phenoxy)phenol) showing the greatest potency, with an MIC₉₉ of 12.9 µM against M. bovis.

Use of BODIPY-Labeled ATP Analogues in the Development and Validation of a Fluorescence Polarization-Based Assay for Screening of Kinase Inhibitors

The screening of compound libraries to identify small-molecule modulators of specific biological targets is crucial in the process for the discovery of novel therapeutics and molecular probes. Considering the need for simple single-tool assay technologies with which one could monitor "all" kinases, we developed a fluorescence polarization (FP)-based assay to monitor the binding capabilities of protein kinases to ATP. We used BODIPY ATP-y-S as a probe to measure the shift in the polarization of a light beam when passed through the sample. We were able to optimize the assay using commercial Protein Kinase A (PKA) and H7 efficiently inhibited the binding of the probe when added to the reaction. Furthermore, we were able to employ the assay in a high-throughput fashion and validate the screening of a set of small molecules predicted to dock into the ATP-binding site of PKA. This will be useful to screen larger libraries of compounds that may target protein kinases by blocking ATP binding.

1,000,000 cases of COVID-19 outside of China: The date predicted by a simple heuristic

We forecast 1,000,000 COVID-19 cases outside of China by March 31st, 2020 based on a heuristic and WHO situation reports. We do not model the COVID-19 pandemic; we model only the number of cases. The proposed heuristic is based on a simple observation that the plot of the given data is well approximated by an exponential curve. The exponential curve is used for forecasting the growth of new cases. It has been tested for the last situation report of the last day. Its accuracy has been 1.29% for the last day added and predicted by the 57 previous WHO situation reports (the date 18 March 2020). Prediction, forecast, pandemic, COVID-19, coronavirus, exponential growth curve parameter, heuristic, epidemiology, extrapolation, abductive reasoning, WHO situation report.

VIDAS® Enzyme-Linked Immunofluorescent Assay for Detection of Listeria in Foods: Collaborative Study

The VIDAS LIS method and the traditional culture methods for detection of Listeria species in food were evaluated in a multilaboratory comparative study. The 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of Listeria. Results for each food and each contamination level with the VIDAS LIS method were as good as or better than those obtained with the traditional culture method. Of 1558 samples tested, 935 were positive: 839 by the VIDAS method and 809 by standard culture methods. Overall false negative rates were 10.3 and 13.5% for the VIDAS LIS and culture methods, respectively. The false positive rate for the VIDAS LIS assay was 1.4% based on 9 VIDAS LIS positive assays that did not confirm positive by isolation of Listeria. The agreement between the VIDAS LIS and culture methods for all samples tested was 86%.

Systemic neoadjuvant chemotherapy in modern pancreatic cancer treatment: a systematic review and meta-analysis

BACKGROUND

Pancreatic ductal adenocarcinoma remains a disease with a poor prognosis despite advances in surgery and systemic therapies. Neoadjuvant therapy strategies are a promising alternative to adjuvant chemotherapy. However, their role remains controversial. This meta-analysis aims to clarify the benefits of neoadjuvant therapy in resectable pancreatic ductal adenocarcinoma.

METHODS

Eligible studies were identified from MEDLINE, Embase, Web of Science and the Cochrane Library. Studies comparing neoadjuvant therapy with a surgery first approach (with or without adjuvant therapy) in resectable pancreatic ductal adenocarcinoma were included. The primary outcome assessed was overall survival. A random-effects meta-analysis was performed, together with pooling of unadjusted Kaplan-Meier curve data.

RESULTS

A total of 533 studies were identified that analysed the effect of neoadjuvant therapy in pancreatic ductal adenocarcinoma. Twenty-seven studies were included in the final data synthesis. Meta-analysis suggested beneficial effects of neoadjuvant therapy with prolonged survival compared with a surgery-first approach, (hazard ratio 0.72, 95% confidence interval 0.69-0.76). In addition, R0 resection rates were significantly higher in patients receiving neoadjuvant therapy (relative risk 0.51, 95% confidence interval 0.47-0.55). Individual patient data analysis suggested that overall survival was better for patients receiving neoadjuvant therapy (P = 0.008).

CONCLUSIONS

Current evidence suggests that neoadjuvant chemotherapy has a beneficial effect on overall survival in resectable pancreatic ductal adenocarcinoma in comparison with upfront surgery and adjuvant therapy. Further trials are needed to address the need for practice change.

Interobserver agreement of digital dermatitis M-scores for photographs of the hind feet of standing dairy cattle

Digital dermatitis (DD) is the leading infectious cause of lameness in dairy cattle, and it affects their welfare and productivity worldwide. At the herd level, DD is often assessed while cows are standing in a milking parlor, and lesions are most commonly evaluated using the M-score. The objective of this study was to examine the interobserver agreement for M-scores of the feet of standing cattle, based on digital color photographs of dairy cattle hind feet. A total of 88 photographs and written descriptors of the M-score were sent to 11 scorers working at 10 different institutions in 5 countries. The scorers received no formal training immediately before scoring the photographs; however, all regularly used the M-score to score DD. The answers for 36 photographs were excluded from the analysis because the photograph either had more than 1 M-stage as mode or not all scorers assigned an M-score to it. The M-scores of the 11 scorers from 52 photographs were available for analysis. Interobserver agreement was tested using Gwet's agreement coefficient (AC1) and the mode was assumed correct. Overall, moderate agreement emerged for the M-score (AC1 = 0.48). For the individual M-stages, almost perfect agreement existed for M0 (AC1 = 0.99), M1 (AC1 = 0.92), and M3 (AC1 = 0.82), and substantial agreement for M2 (AC1 = 0.61), M4 (AC1 = 0.65), and M4.1 (AC1 = 0.71). This outcome indicates the degree of individual variation in M-scoring in this context by unstandardized, experienced European observers, particularly for the M2, M4, and M4.1 stages. Standardized training is likely to improve the consistency of M-scoring and thus the generalizability of future DD research results on this important endemic disease.

Abstract P2-09-10: Epigenetic modulation—unlocking the potential of checkpoint inhibition in breast cancer

Immune checkpoint inhibition (ICI) has revolutionized treatment in cancers that are naturally immunogenic by enabling infiltration of T cells into the tumor microenvironment (TME) and promoting cytotoxic signaling pathways. Tumors possessing complex immunosuppressive TME's such as breast cancer present unique therapeutic obstacles as response rates to ICI remain low. Such tumors often recruit myeloid-derived suppressor cells (MDSCs) whose functioning prohibits both T cell activation and infiltration. To date, most studies focus on use of ICI in triple negative disease. Our work aims to uncover the efficacy of ICI in both early and advanced HER2 positive (HER2+) disease and to advance our understanding of how to improve response rates to these new promising therapies.

We are using a HER-2/neu transgenic mouse model with tumor challenge of syngeneic cell lines to test the efficacy of different combinations of an epigenetic agent, the histone deacetylase inhibitor entinostat (ENT), checkpoint inhibitors anti-PD-1 and anti- CTLA-4, on primary and metastatic disease. We are examining treatment effects on primary tumor growth, metastatic burden, and survival. Characterization of tumor infiltrating lymphocytes and their functional capabilities are being investigated using fluorescence-activated cell sorting, gene expression profiling, and ex vivo suppression assays. Western blots, qPCR and other in vitro assays will be performed on MDSCs to investigate mechanisms behind response.

In the HER2+ mouse model of early stage disease, we show that combining ENT, with ICis significantly improves survival and delays tumor growth. Preliminary data in models of advanced disease, show only ENT + a-PD-1 improves survival and metastatic burden. Conversely, in the metastatic model, ENT + a-CTLA-4 negatively effects survival and metastatic burden. In primary tumors, ENT + ICIs leads to significantly decreased suppression by granulocytic-MDSCs. However, MDSC infiltration and function is not affected in lungs containing macrometastatic disease. Interestingly, we found an increase in activated granzyme-B-producing CD8+ T effector cells in mice treated with combination therapy in both primary and metastatic tumors. Finally, gene expression profiling of MDSCs from primary tumors identified significant changes in immune-related pathways, and identified a common downstream regulator –STAT3. Studies are ongoing to evaluate the mechanistic role of STAT3 in the response observed in primary tumors and to determine if STAT3 is involved in response in the metastatic setting.

In summary, addition of ENT to ICIs significantly affects overall survival in early stage models of HER2+ breast cancer however, only addition of a-PD-1 to ENT is beneficial in models of advanced disease. Additionally, the mechanism of action in early stage disease involves altered infiltration and function of MDSCs, allowing for a more robust adaptive immune response. However, a different mechanism of action is likely responsible for the responses seen in advanced stage disease. These novel findings provide a rationale for combination therapy in patients with HER2+ breast cancer and suggest responses to this combination therapy are linked to stage of disease likely due to different mechanisms of action.

Citation Format: Roussos Torres ET, Rafie C, Armstrong T, Jaffee EM. Epigenetic modulation—unlocking the potential of checkpoint inhibition in breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-10.

Proactive multi-modality treatment of Pancreatic Neuroendocrine Tumours (PNETs): Potential survival benefits

BACKGROUND/OBJECTIVES

Primary and metastatic pancreatic neuroendocrine tumours (PNET) can be treated with combination of surgery, locoregional and systemic therapy. Survival benefits from individual treatments have been well reported, however, the combined outcome from multimodal treatments are not well described in the literature. We report outcomes in a cohort of PNET patients treated with proactive, multimodality therapy.

METHODS

106 patients were identified from a single tertiary referral centre prospective database. Outcomes of treatment were studied, with the primary end point being death from any cause.

RESULTS

Median follow-up was 71 months and overall 5-year survival of 62%. In patients with stage I-III disease (51 patients) estimated 5-year survival was 90%. Median survival in patients with stage IV disease was 51 months with an estimated 5-year survival of 40% in this group. A total of 80 patients (75%) had surgery of which 16% suffered complications requiring intervention. There was no perioperative mortality.

CONCLUSIONS

This study demonstrates that proactive multimodal treatment is safe and may confer a survival benefit to patients in this cohort compared to historical data.

Abstract OT2-06-01: Phase I/II study of T-DM1 alone versus T-DM1 and metronomic temozolomide in secondary prevention of HER2-Positive breast cancer brain metastases following stereotactic radiosurgery

Background: Brain metastases occur in up to 25-40% of HER2+ breast cancer patients. Standard treatment is limited to surgery or stereotactic radiosurgery (SRS) and/or whole brain radiation therapy (WBRT), with high levels of recurrence or progression, limiting survival and quality of life in most patients. Our group has demonstrated that low doses of temozolomide (TMZ) administered in a prophylactic, metronomic fashion can significantly prevent development of brain metastases in murine models of breast cancer. Based on these findings, we propose a secondary-prevention clinical trial.

Trial Design: Phase I/II open label study. Phase I will follow a standard 3+3 design: T-DM1 3.6 mg/kg IV every 21 days plus TMZ 30, 40 or 50 mg/m2 daily. Phase II: randomization T-DM1 3.6 mg/kg versus T-DM1 3.6mg/kg plus TMZ at recommended phase 2 dose (RP2D). Patients will undergo radiology guided lumbar puncture at baseline and after 6 weeks of treatment (C3D1) for correlative studies, brain MRI, systemic restaging CTs, and questionnaires for evaluation of symptoms and quality of life (MDASI-BT and PROMIS®) every 6 weeks.

Eligibility: HER2+ breast cancer with ≤3 brain metastases, treated with SRS and/or resection ≤6 weeks before enrollment, no leptomeningeal metastases, no previous WBRT, able to complete brain MRI with contrast evaluations, willing to undergo lumbar puncture, ECOG ≤2 and adequate organ and marrow function. HBV, HCV or HIV-positive patients are ineligible.

Specific Aims: Phase I: to identify the maximum tolerated dose (MTD) of TMZ combined with T-DM1. Phase II: to determine if the combination regimen of T-DM1 and TMZ improves the recurrence-free incidence from distant new brain metastases at one year as compared to T-DM1 alone. Biomarkers, including cell free DNA sequencing from CSF, serum and tumor block, serum markers for neuroinflammation, and patient reported outcomes, will be analyzed in an exploratory fashion.

Statistical Methods: Phase I, MTD will be identified based on the dose level at which 0 or 1 patient in 6 has a DLT. Phase II, to test whether TMZ will increase RFS from 50% to 65% at 12 months. RFS Kaplan-Meier curves will be created for each of the randomized arms and compared using a one-tailed log-rank test, with a one-sided 0.10 significance level of interest to be detected. Patients will be stratified for number of brain lesions and status of systemic metastases (controlled or not).

Target Accrual: 49 evaluable patients per arm (total 98), plus 9 to 18 patients during phase I. Trial will open in Summer 2017, at NIH in Bethesda, MD.

Contact Information: Principal Investigator: Alexandra S Zimmer, MD alexandra.zimmer@nih.gov

Citation Format: Zimmer AS, Gril B, Steinberg S, Smart D, Gilbert M, Armstrong T, Xiao L, Houston N, Biassou N, Brastianos P, Carter S, Lyden DC, Lipkowitz S, Steeg P. Phase I/II study of T-DM1 alone versus T-DM1 and metronomic temozolomide in secondary prevention of HER2-Positive breast cancer brain metastases following stereotactic radiosurgery [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-06-01.

Abstract P1-08-01: Combination checkpoint inhibition and epigenetic modulation promotes tumor suppression and improves survival in Her2+ models of breast cancer

Background: Checkpoint inhibition is a very successful treatment strategy in cancers that are naturally immunogenic by attracting T cells into the tumor microenvironment (TME) and promoting cytotoxic signaling pathways. While this strategy has shown some efficacy in metastatic breast cancer, most breast cancers are not highly immunogenic likely due to an immunosuppressive microenvironment and a lack of tumor antigen expression and recognition. One strategy to transform the breast TME is to use epigenetic modulation to affect activation and trafficking of myeloid derived suppressor cells (MDSCs), known to alter the immunogenicity of the TME and sensitize tumors to checkpoint modulation. We hypothesize that combinatorial therapy primes the TME by altering infiltration and function of MDSCs leading to a more robust T cell response. Methods: We are using a HER-2/neu transgenic mouse model with tumor challenge of syngeneic cell lines to test the efficacy of different combinations of an epigenetic agent, the histone deacetylase inhibitor entinostat (ENT), checkpoint inhibitors anti -programmed cell death protein (a-PD-1) and anti-cytotoxic T-lymphocyte-associated protein 4 (a-CTLA-4) antibodies, with and without anti-HER2 antibodies. We will examine treatment effects on tumor growth, and hope to identify co-stimulatory and inhibitory factors regulating T cell and MDSC responses. Characterization of tumor infiltrating lymphocytes and their functional capabilities are being investigated in primary tumors using fluorescence-activated cell sorting, nanostring gene expression profiling, and immunohistochemistry. Results: We found significant improvement in survival and delay in tumor growth in mice treated with ENT in combination with a-PD-1 and/or a-CTLA-4. Addition of anti-HER2 therapy to ENT and a-CTLA4 or a-PD1 also significantly improves survival and delay in tumor growth. We also found addition of ENT to checkpoint inhibition leads to significantly increased infiltration of granulocytic-MDSCs into the TME. We demonstrate an increase in CD8+ T effector cells in mice treated with combination therapy. Flow cytometric evaluation of markers of T cell activation, exhaustion, and MDSC function demonstrate significantly increased T cell activation, exhaustion, and myeloid function however it is unclear how this directly effects the phenotype we have observed in these mice. Gene expression profiling of both MDSCs and lymphocytes infiltrating tumors is underway to help determine significant changes in immune related pathways that lead to our observed outcomes. Conclusions: Addition of ENT to checkpoint inhibition significantly increases infiltration of innate and adaptive immune cells into the highly tolerant neu-N breast tumors and leads to improved survival and decreased tumor burden. Functional assays are underway and future studies will further delineate changes in immune infiltration as well as genetic alterations responsible for these observations. It is our hope that these novel findings will provide further rationale for combination therapy and improve the response rate of these immune therapies in patients with breast cancer.

Citation Format: Roussos Torres ET, Ma H, Christmas B, Armstrong T, Jaffee EM. Combination checkpoint inhibition and epigenetic modulation promotes tumor suppression and improves survival in Her2+ models of breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-08-01.

PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer

BACKGROUND

Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer.

OBJECTIVE

To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer.

DESIGN

A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy.

PARTICIPANTS

Patients with suspected pancreatic malignancy.

INTERVENTIONS

All patients to undergo PET/CT following standard diagnostic work-up.

MAIN OUTCOME MEASURES

The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours.

RESULTS

Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUVmax.) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity (p = 0.01) and specificity (p = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios (p < 0.0002). PET/CT correctly changed the staging of pancreatic cancer in 56 patients (p = 0.001). PET/CT influenced management in 250 (45%) patients. PET/CT stopped resection in 58 (20%) patients who were due to have surgery. The benefit of PET/CT was limited in patients with chronic pancreatitis or other pancreatic tumours. PET/CT was associated with a gain in quality-adjusted life-years of 0.0157 (95% confidence interval -0.0101 to 0.0430). In the base-case model PET/CT was seen to dominate MDCT alone and is thus highly likely to be cost-effective for the UK NHS. PET/CT was seen to be most cost-effective for the subgroup of patients with suspected pancreatic cancer who were thought to be resectable.

CONCLUSION

PET/CT provided a significant incremental diagnostic benefit in the diagnosis of pancreatic cancer and significantly influenced the staging and management of patients. PET/CT had limited utility in chronic pancreatitis and other pancreatic tumours. PET/CT is likely to be cost-effective at current reimbursement rates for PET/CT to the UK NHS. This was not a randomised controlled trial and therefore we do not have any information from patients who would have undergone MDCT only for comparison. In addition, there were issues in estimating costs for PET/CT. Future work should evaluate the role of PET/CT in intraductal papillary mucinous neoplasm and prognosis and response to therapy in patients with pancreatic cancer.

STUDY REGISTRATION

Current Controlled Trials ISRCTN73852054 and UKCRN 8166.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Abstract P2-04-11: Promotion of immunogenicity using epigenetic modulation and immune checkpoint inhibition in mouse models of breast cancer

This abstract was not presented at the symposium.

Propensity score-based analysis of outcomes of laparoscopic versus open liver resection for colorectal metastases

BACKGROUND

There is a need for high-level evidence regarding the added value of laparoscopic (LLR) compared with open (OLR) liver resection. The aim of this study was to compare the surgical and oncological outcomes of patients with colorectal liver metastases (CRLM) undergoing LLR and OLR using propensity score matching to minimize bias.

METHODS

This was a single-centre retrospective study using a prospective database of patients undergoing liver resection for CRLM between August 2004 and April 2015. Co-variates selected for matching included: number and size of lesions, tumour location, extent and number of resections, phase of surgical experience, location and lymph node status of primary tumour, perioperative chemotherapy, unilobar or bilobar disease, synchronous or metachronous disease. Prematching and postmatching analyses were compared. Surgical and oncological outcomes were analysed.

RESULTS

Some 176 patients undergoing LLR and 191 having OLR were enrolled. After matching, 133 patients from each group were compared. At prematching analysis, patients in the LLR group showed a longer overall survival (OS) and higher R0 rate than those in the OLR group (P = 0·047 and P = 0·030 respectively). Postmatching analyses failed to confirm these results, showing similar OS and R0 rate between the LLR and OLR group (median OS: 55·2 versus 65·3 months respectively, hazard ratio 0·70 (95 per cent c.i. 0·42 to 1·05; P = 0·082); R0 rate: 92·5 versus 86·5 per cent, P = 0·186). The 5-year OS rate was 62·5 (95 per cent c.i. 45·5 to 71·5) per cent) for OLR and 64·3 (48·2 to 69·5) per cent for LLR. Longer duration of surgery, lower blood loss and morbidity, and shorter postoperative stay were found for LLR on postmatching analysis.

CONCLUSION

Propensity score matching showed that LLR for CRLM may provide R0 resection rates and long-term OS comparable to those for OLR, with lower blood loss and morbidity, and shorter postoperative hospital stay.

Target validation of the inosine monophosphate dehydrogenase (IMPDH) gene in Cryptosporidium using Phylomer(®) peptides

Cryptosporidiosis, a gastroenteric disease characterised mainly by diarrheal illnesses in humans and mammals is caused by infection with the protozoan parasite Cryptosporidium. Treatment options for cryptosporidiosis are limited, with the current therapeutic nitazoxanide, only partly efficacious in immunocompetent individuals. The parasite lacks de novo purine synthesis, and is exclusively dependant on purine salvage from its host. Inhibition of the inosine 5' monophosphate dehydrogenase (IMPDH), a purine salvage enzyme that is essential for DNA synthesis, thereby offers a potential drug target against this parasite. In the present study, a yeast-two-hybrid system was used to identify Phylomer peptides within a library constructed from the genomes of 25 phylogenetically diverse bacteria that targeted the IMPDH of Cryptosporidium parvum (IMPcp) and Cryptosporidium hominis (IMPch). We identified 38 unique interacting Phylomers, of which, 12 were synthesised and screened against C. parvum in vitro. Two Phylomers exhibited significant growth inhibition (81.2-83.8% inhibition; P < 0.05), one of which consistently exhibited positive interactions with IMPcp and IMPch during primary and recapitulation yeast two-hybrid screening and did not interact with either of the human IMPDH proteins. The present study highlightsthe potential of Phylomer peptides as target validation tools for Cryptosporidium and other organisms and diseases because of their ability to bind with high affinity to target proteins and disrupt function.

Ergonomic Aspects of Clinical and Surgical Procedures

This discussion panel aims to identify ergonomic concerns, solutions and research needs, physical stresses, and outcomes related to clinical and surgical procedures. This session will begin with formal presentations to demonstrate current ergonomic concerns and research initiatives associated with clinical and surgical procedures to frame the panel discussion for the second part of the session. Discussion of different procedures will help to identify solutions and research needs that relate to a broad range of ergonomic problems. Questions will be collected from the attendees and speakers and organized so as to guide the panel discussion and to engage all of the speakers in the discussion to achieve the symposium aims.

A standardized method for measuring the force required to join wire harnesses and sparkplugs

Understanding the forces required to insert a sparkplug wire (wire) onto a sparkplug (plug), independent of worker variation, is important for ergonomists, engineers, and designers. This paper describes a methodology for measuring the forces required to seat a wire onto a plug. A three-axis programmable mill was used to insert wires onto plugs mounted on a force transducer. Inflection points and slopes of the force-displacement curves were found to correspond to mechanical events as the plug and wire were joined. These events were further isolated by dissecting the wires to better understand the force contribution of each wire component. Liner superposition was then used to show that each of these force elements may be added to estimate the total force required to seat a wire onto a plug. This methodology may be used to quantify the effects of design choices, lubricants (wet and dry), and pre-working on axial insertion forces associated with sparkplugs and other insertions. This paper does not address worker abilities or variation, however, the methodology and equipment described may provide a foundation for the exploration of worker ability, variation and work techniques.

The epidemiology of overweight and obesity among Australian children and adolescents, 1995-97

OBJECTIVES

To determine the population prevalence of overweight and obesity among Australian children and adolescents, based on measured body mass index (BMI). To determine if overweight and obesity are distributed differentially across the population of young Australians.

METHODS

Data from three independent surveys were analysed. In each, height and weight were measured by trained surveyors using valid, comparable methods. BMI (kg/m2) was used as the index of adiposity and recently published international BMI cut-off values used to categorise each subject as non-overweight, overweight or obese.

RESULTS

The population prevalence and distribution of overweight, obesity and overweight/obesity combined were generally consistent across datasets. The ranges of the prevalence of non-overweight, overweight, obesity and overweight/obesity combined were 79-81%, 14-16%, 5% and 19-21% (boys) respectively and 76-79%, 16-18%, 5-6% and 21-24% (girls). There were no consistent relationships between the prevalence of overweight/obesity and sex, age or SES. Their prevalence was up to 4% higher in urban than rural areas among boys, but there were no differences between urban and rural girls. The data suggest a higher prevalence of overweight/ obesity among students from European or Middle-Eastern cultural backgrounds.

CONCLUSIONS

Some 19-23% of Australian children and adolescents are either overweight or obese. Although urban/rural, SES and cultural background differentials were noted, only the last warrants a targeted health promotion response.

IMPLICATIONS

Overweight/obesity is a prevalent health risk factor among Australian children and adolescents. More information is needed to understand whether targeted approaches are required for specific ethnic groups in addition to broad, population-based approaches.