Abstract P207: BBP-398, a potent, small molecule inhibitor of SHP2, enhances the response of established NSCLC xenografts to KRASG12C and mutEGFR inhibitors

Src homology 2 domain-containing phosphatase (SHP2), a ubiquitously expressed non-receptor tyrosine phosphatase, plays a critical role in the regulation of the MAPK signaling pathway and cellular proliferation. Activating mutations in SHP2 are associated with the development of multiple malignancies including leukemia, lung cancer and neuroblastoma. In addition, SHP2 promotes the conversion of oncogenic KRAS to its active GTP-bound state and it’s inhibition can enhance efficacy of GDP-KRASG12C inhibitors as well as other MAPK pathway inhibitors (RAF, MEK and ERK) which have suboptimal clinical efficacy as single agents. As a result, inhibition of SHP2 through genetic manipulation or pharmacological means has been shown to suppress tumor growth and presents an attractive potential avenue for the treatment of malignancies as monotherapy or in combination with other MAPK/PI3K inhibitors. Here we describe BBP-398, a potent, orally bioavailable allosteric small molecule inhibitor of SHP2. BBP-398 displays high selectivity against other phosphatases, kinases, GPCRs, transporters and hERG. Predicted human PK properties show good oral bioavailability with half-life of ~12-16 hours enabling continuous daily dosing and optimal therapeutic index in combination with other targeted therapeutics. In cellular assays, BBP-398 demonstrates potent pERK/DUSP6 inhibition and loss of viability across a panel of cell lines with active MAPK signaling, such as mutant EGFR and KRASG12C. In vivo, BBP-398 strongly suppresses RAS-ERK signaling in RTK- or RAS-driven xenografts. In the EGFR-dependent non-small cell lung cancer (NSCLC) HCC827 and esophageal squamous cell carcinoma KYSE-520 xenograft models, BBP-398 drives dose dependent efficacy consistent with the level of target inhibition. Detailed analysis of tumor response shows that efficacy is driven by maintaining better than 50% inhibition of pERK for most of the dosing interval. In addition to its strong single agent activity, BBP-398 also leads to enhanced efficacy in vitro and in vivo when used in combination with targeted therapeutics against driver MAPK genetic alterations, such as KRAS, EGFR or MET. Combination targeting, such as with the GDP-KRASG12C inhibitor sotorasib in the NSCLC NCI-H358 xenograft model, or with the mutant EGFR inhibitor osimertinib in the HCC827 erlotinib resistant (ER) xenograft model, drives strong suppression of MAPK activity and results in tumor regressions. Collectively, these findings highlight that SHP2 inhibition is a promising molecular therapeutic strategy in cancer which can potentially strongly suppress tumor growth as a single agent or in combination with other MAPK pathway inhibitors. Given its preclinical properties and projected favorable clinical pharmacokinetic profile, BBP-398 is currently being evaluated in a Phase 1/1b trial in patients with advanced solid tumors (NCT04528836).

Citation Format: James P. Stice, Sofia Donovan, Yuting Sun, Nancy Kohl, Barbara Czako, Faika Mseeh, Paul Leonard, Anna Wade, Justin Lim, Phil Jones, Eli Wallace, Kerstin Sinkevicius, Pedro Beltran. BBP-398, a potent, small molecule inhibitor of SHP2, enhances the response of established NSCLC xenografts to KRASG12C and mutEGFR inhibitors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P207.

Epidemiology and outcome of status epilepticus in children: a Scottish population cohort study

AIM

To describe the epidemiology and outcomes of convulsive status epilepticus (CSE) since the introduction of buccal midazolam and the change in International League Against Epilepsy definition of CSE to include seizures of at least 5 minutes.

METHOD

All children presenting to paediatric emergency departments with CSE (2011-2017) in Lothian, Scotland, were identified. Data, collated from electronic health records, included patient demographics, clinical characteristics, acute seizure management, and adverse outcomes (for example admission to intensive care).

RESULTS

Six hundred and sixty-five children were admitted with CSE who had 1228 seizure episodes (381 males, 284 females; median age 3y 8mo; age range 0-20y 11mo). CSE accounted for 0.38% (95% confidence interval 0.34-0.42) of annual attendances at emergency departments. Annual prevalence was 0.8 per 1000 children aged 0 to 14 years. Thirty-four per cent of children had recurrent CSE. Sixty-nine per cent of seizures lasted 5 to 29 minutes (median duration 10min). Buccal midazolam was given to 30% of children with CSE and had no effect on need for ventilatory support. Seventy per cent of children with CSE required hospital admission. Four per cent resulted in adverse outcome and there were only two deaths. Recurrent seizures, longer duration, and unprovoked seizures increased the odds of adverse outcome.

INTERPRETATION

Adverse outcomes have decreased and the use of buccal midazolam is promising. Identifying high-risk groups provides an opportunity for early intervention. These data form the basis for an extensive evaluation of acute seizure management and monitoring long-term outcomes. What this paper adds The annual prevalence of convulsive status epilepticus in Lothian, Scotland, was 0.8 per 1000 children. There was a decrease in case-fatality proportion from 3-9% to 0.2%. Use of buccal midazolam has increased, with no increase in adverse outcomes.

Mapping potential effects of proposed roads on migratory connectivity for a highly mobile herbivore using circuit theory

Migration is common worldwide as species access spatiotemporally varying resources and avoid predators and parasites. However, long-distance migrations are increasingly imperiled due to development and habitat fragmentation. Improved understanding of migratory behavior has implications for conservation and management of migratory species, allowing identification and protection of seasonal ranges and migration corridors. We present a technique that applies circuit theory to predict future effects of development by analyzing season-specific resistance to movement from anthropogenic and natural environmental features across an entire migratory path. We demonstrate the utility of our approach by examining potential effects of a proposed road system on barren ground caribou (Rangifer tarandus granti) and subsistence hunters in northern Alaska. Resource selection functions revealed migratory selection by caribou. We tested five scenarios relating habitat selection to landscape resistance using Circuitscape and GPS telemetry data. To examine the effect of potential roads on connectivity of migrating animals and human hunters, we compared current flow values near communities in the presence of proposed roads. Caribou avoided dense vegetation, rugged terrain, major rivers, and existing roads in both spring and fall. A negative linear relationship between resource selection and landscape resistance was strongly supported for fall migration while spring migration featured a negative logarithmic relationship. Overall patterns of caribou connectivity remained similar in the presence of proposed roads, though reduced current flow was predicted for communities near the center of current migration areas. Such data can inform decisions to allow or disallow projects or to select among alternative development proposals and mitigation measures, though consideration of cumulative effects of development is needed. Our approach is flexible and can easily be adapted to other species, locations and development scenarios to expand understanding of movement behavior and to evaluate proposed developments. Such information is vital to inform policy decisions that balance new development, resource user needs, and preservation of ecosystem function.

Allosteric SHP2 Inhibitor, IACS-13909, Overcomes EGFR-Dependent and EGFR-Independent Resistance Mechanisms toward Osimertinib

Src homology 2 domain-containing phosphatase (SHP2) is a phosphatase that mediates signaling downstream of multiple receptor tyrosine kinases (RTK) and is required for full activation of the MAPK pathway. SHP2 inhibition has demonstrated tumor growth inhibition in RTK-activated cancers in preclinical studies. The long-term effectiveness of tyrosine kinase inhibitors such as the EGFR inhibitor (EGFRi), osimertinib, in non-small cell lung cancer (NSCLC) is limited by acquired resistance. Multiple clinically identified mechanisms underlie resistance to osimertinib, including mutations in EGFR that preclude drug binding as well as EGFR-independent activation of the MAPK pathway through alternate RTK (RTK-bypass). It has also been noted that frequently a tumor from a single patient harbors more than one resistance mechanism, and the plasticity between multiple resistance mechanisms could restrict the effectiveness of therapies targeting a single node of the oncogenic signaling network. Here, we report the discovery of IACS-13909, a specific and potent allosteric inhibitor of SHP2, that suppresses signaling through the MAPK pathway. IACS-13909 potently impeded proliferation of tumors harboring a broad spectrum of activated RTKs as the oncogenic driver. In EGFR-mutant osimertinib-resistant NSCLC models with EGFR-dependent and EGFR-independent resistance mechanisms, IACS-13909, administered as a single agent or in combination with osimertinib, potently suppressed tumor cell proliferation in vitro and caused tumor regression in vivo. Together, our findings provide preclinical evidence for using a SHP2 inhibitor as a therapeutic strategy in acquired EGFRi-resistant NSCLC. SIGNIFICANCE: These findings highlight the discovery of IACS-13909 as a potent, selective inhibitor of SHP2 with drug-like properties, and targeting SHP2 may serve as a therapeutic strategy to overcome tumor resistance to osimertinib.

Abstract 1516: Deep profiling of T-cell repertoire and tumor heterogeneity in chronic lymphocytic leukemia patients following allogeneic T-cell therapy

Chemotherapy/ targeted therapy are both known to trigger evolution of treatment resistant clones that can lead to relapse. Allogeneic stem cell transplant (alloSCT) for refractory Chronic Lymphocytic Leukemia (CLL) patients is associated with better outcomes. We hypothesized that allogeneic T-cell immunotherapies, including alloSCT and donor lymphocyte infusion (DLI) would impact tumor evolution through the application of selective immunologic pressure with reciprocal changes in the T-cell compartment. Here, we tested a cohort of 24 heavily pre-treated CLL patients treated. Treatments consisted of alloSCT alone, or with follow-up DLI, which are two established mediators of effective Graft versus Leukemia (GVL). Our cohort included 11 patients who relapsed (denoted as non-responder, NR) after alloSCT and 13 patients who had complete response (CR) after alloSCT, with 11/13 patients showing durable CR with a median post-transplant overall survival (OS) of 9.8 years. We mapped the evolutionary trajectories of tumor cells by whole exome sequencing (WES) of sort purified CLL in post-transplant relapsed patients. To investigate changes in immune repertoire and gene expression post-transplant, CD3 positive T-cells from peripheral blood and bone marrows of CLL patients at complete donor chimerism were analyzed both at bulk and at the single cell level. We found evidence of subclonal leukemic evolution in the majority of our CLL patient cohort after nonmyeloablative HLA-matched alloSCT. Different patterns of CLL evolution were observed, and these changes included putative CLL drivers in every case. In all of the 11 patients with longitudinal post-alloSCT samples available, we observed branched CLL evolution in 4 patients, linear evolution in 4 patients, and no evolution in 3 patients. These data suggest that differential sensitivity of leukemic subclones to allogeneic T cell killing may underlie the branched and linear evolution that we observed, and therefore can shape leukemic subclonal architecture after transplant. Of note, we found that clonal CLL was more responsive to alloSCT in comparison to CLL with subclonal disease architecture.To identify T-cells with GVL potential, we first cataloged potential neoantigens by screening mutated regions in CLL with in silico HLA binding prediction models. Neoantigen specific T-cells were then sorted from longitudinal peripheral blood samples using tetramers, followed by identification of GVL specific TCR in both bulk and single cell setting. We were able to identify T-cells that coevolved with specific tumorigenic lesions in a subset of CLL patients. Taken together, our results suggest that donor-derived antigen-specific T-cells mediate clonal selection of CLL with concurrent changes in allogeneic T-cells, and that these changes can be monitored in longitudinal patient samples.

Citation Format: Celine Kerros, John P. Miller, Xizeng Mao, Haven R. Garber, Hannah C. Beird, Jianhua Zhang, Jason Roszik, Paul Leonard, Li Zhao, Sahil Seth, Pei Lin, Huandong Sun, William G. Wierda, Issa F. Khouri, Karen Clise-Dwyer, Andrew Futreal, Shoudan Liang, Koppikar Priya, Jeffrey Molldrem. Deep profiling of T-cell repertoire and tumor heterogeneity in chronic lymphocytic leukemia patients following allogeneic T-cell therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1516.

Functional Genomics Reveals Synthetic Lethality between Phosphogluconate Dehydrogenase and Oxidative Phosphorylation

The plasticity of a preexisting regulatory circuit compromises the effectiveness of targeted therapies, and leveraging genetic vulnerabilities in cancer cells may overcome such adaptations. Hereditary leiomyomatosis renal cell carcinoma (HLRCC) is characterized by oxidative phosphorylation (OXPHOS) deficiency caused by fumarate hydratase (FH) nullizyogosity. To identify metabolic genes that are synthetically lethal with OXPHOS deficiency, we conducted a genetic loss-of-function screen and found that phosphogluconate dehydrogenase (PGD) inhibition robustly blocks the proliferation of FH mutant cancer cells both in vitro and in vivo. Mechanistically, PGD inhibition blocks glycolysis, suppresses reductive carboxylation of glutamine, and increases the NADP⁺/NADPH ratio to disrupt redox homeostasis. Furthermore, in the OXPHOS-proficient context, blocking OXPHOS using the small-molecule inhibitor IACS-010759 enhances sensitivity to PGD inhibition in vitro and in vivo. Together, our study reveals a dependency on PGD in OXPHOS-deficient tumors that might inform therapeutic intervention in specific patient populations.

Can paediatric emergency clinicians identify and manage clavicle fractures without radiographs in the emergency department? A prospective study

BACKGROUND

Paediatric clavicle fractures are commonly seen in the emergency department (ED), and the current standard of care is to obtain a radiograph for all suspected clavicle fractures. We are yet to determine whether radiographs add valuable information to clinicians' assessment and therefore if they are necessary in the management of paediatric clavicle fractures.

OBJECTIVE

To determine whether clinicians can manage paediatric clavicle fractures without radiographs, first by determining the accuracy of clinicians in identifying the presence of a clavicle fracture, and second by evaluating the level of agreement (kappa (κ)) between the ultimate management of children with suspected clavicle fractures and clinicians' blinded prediction prior to the radiograph.

METHODS

This prospective study enrolled patients presenting to a paediatric ED with a suspected clavicle fracture. Prior to requesting a radiograph, clinicians completed a standardised form, where they predicted the presence of a fracture and their ultimate management based on their clinical findings, and rated their confidence.

RESULTS

Of the 50 patients aged 7.2±3.9 years included, 40 (80%) had a radiologically proven clavicle fracture, and clinicians were able to accurately identify them (sensitivity 93%, positive predictive value 88%). There were five (50%) patients without a radiological fracture that were treated with broad arm sling. Clinicians' prediction of ultimate management had the highest agreement with the ultimate management of the patient on leaving the ED, compared with clinicians' prediction of the presence of fracture and the final radiograph findings: κ of 0.88 (95% CI 0.64 to 1), 0.67 (95% CI 0.36 to 0.98) and 0.62 (95% CI 0.30 to 0.94), respectively. Thirty-six (72%) of the clinicians felt comfortable treating without radiographs, and this was dependent on their level of training.

CONCLUSIONS

Clinicians can identify the presence of a fracture and tend to be overconservative in their management. Despite negative radiological findings, some patients were treated as though they had a fracture, based on clinical judgement. This adds evidence that radiographs are not routinely required for uncomplicated paediatric clavicle fractures.

Abstract LB-071: Discovery of an imidazopyridine series of potent human IDO1 inhibitors with robust target engagement in a preclinical tumor model

Indoleamine 2,3-dioxygenase (IDO1 and IDO2) and tryptophan dioxygenase (TDO) are heme-containing enzymes that mediate the rate limiting step in the oxidative degradation of L-tryptophan (L-TRP) to kynurenine (KYN) metabolites. Tryptophan catabolism through the KYN metabolic pathway is now recognized as one of many mechanisms involved in tumor cell evasion of the immune surveillance system. Inhibition of the KYN pathway in the tumor microenvironment can lead to improved immune response and tumor growth suppression. Recently, clinical proof of concept of this mechanism has been demonstrated using an Indoleamine 2,3-dioxygenase (IDO1) inhibitor in combination with a PD-1 antagonist in a variety of tumor contexts. Consideration of known low molecular weight heme-co-ordinating ligands identified from the PDB, in conjunction with a virtual screen performed in-silico identified a number of potentially interesting starting points for medicinal chemistry development. Identification of an attractive indazole fragment as a starting point, and expansion into alternative bicyclic cores, resulted in the discovery of a family of imidazopyridines as potent human IDO1 inhibitors with >200 fold selectivity against TDO. Utilizing a structure-based design approach allowed rapid lead optimization that resulted in the identification of IACS-8968. Crystallography studies were conducted, and binding of IACS-8968 to the heme domain of the human IDO1 was confirmed. The homochiral imidazopyridine IACS-8968 displayed cellular IC50= 29 nM in a HeLa cell line expressing human IDO1 and IC50= 21 nM in a PANC02 mouse cell line expressing the murine IDO1 enzyme, showed satisfactory selectivity margin (> 150 fold) versus its CYP450 inhibition profile and good oral bioavailability across species. PK/PD experiments indicated that, at equivalent exposure, IACS-8968 (sodium salt) and epacadostat decreased tumor KYN at comparable levels in CT26 syngeneic mouse model.

Citation Format: Alessia Petrocchi, Naphtali J. Reyna, Faika Mseeh, Connor A. Parker, Simon Yu, Quanyun Xu, Ningping Feng, Paul Leonard, Norma Rogers, Jason B. Cross, Angela L. Harris, Yongying Jiang, Tin Oo Khor, Mikhila G. Mahendra, Jihai Pang, Qi Wu, Andy M. Zuniga, Timothy McAfoos, Timothy McAfoos, Matthew M. Hamilton, Joe R. Marszalek, Keith Mikule, Paul Vancutsem, Keith Wilcoxen, Martin Tremblay, Philip Jones, Richard T. Lewis. Discovery of an imidazopyridine series of potent human IDO1 inhibitors with robust target engagement in a preclinical tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-071.

[Multidisciplinary management of alveolar echinococcosis : Echino-Liege Working Group]

Alveolar echinococcosis is a zoonotic disease due to the tapeworm Echinococcus multilocularis. The definitive host is the red fox. Until recently, Belgium was considered a country at very low risk for alveolar echinococcosis. However, recent studies carried out in southern Belgium have revealed, through post-mortem examination, high prevalences (up to 62 %) in foxes. Cats and dogs can act as definitive hosts. Human are accidentally infected by ingestion of food contaminated by the feces. After a long incubation period, invasive hepatic lesions may appear, as well as extra-hepatic lesions. The disease may be fatal. The diagnosis is based on imaging techniques, serology and nucleic acid detection in tissues. Early diagnosis may allow surgical removal of the lesion associated with at least 2 years of albendazole postoperative treatment. In case of contraindication to surgery, a long term treatment with albendazole is necessary. Liver transplantation is sometimes necessary. This article presents the epidemiologic, clinical, diagnostic and therapeutics features of this zoonotic disease.

Measuring Antibody-Antigen Binding Kinetics Using Surface Plasmon Resonance

Surface plasmon resonance (SPR) is now widely embraced as a technology for monitoring a diverse range of protein-protein interactions and is considered almost de rigueur for characterizing antibody-antigen interactions. The technique obviates the need to label either of the interacting species, and the binding event is visualized in real time. Thus, it is ideally suited for screening crude, unpurified antibody samples that dominate early candidate panels following antibody selection campaigns. SPR returns not only concentration and affinity data but when used correctly can resolve the discrete component kinetic parameters (association and dissociation rate constants) of the affinity interaction. Herein, we outline some SPR-based generic antibody screening configurations and methodologies in the context of expediting data-rich ranking of candidate antibody panels and ensuring that antibodies with the optimal kinetic binding characteristics are reliably identified.

Abstract A39: Pomhex, a cell-permeable high potency enolase inhibitor with utility for collateral lethality treatment of cancer

Glycolysis inhibition is an active area of investigation for the treatment of cancer. However, few compounds have progressed beyond the cell culture stage. We have recently demonstrated that genomic passenger deletion of the glycolytic enzyme Enolase 1 (ENO1) leaves gliomas harboring such deletions solely reliant on ENO2, rendering them exquisitely sensitive to enolase inhibitors Collateral Lethality. However, the tool compound that we employed for these in vitro studies, Phosphonoacetohydroxamate (PhAH), has very poor pharmacological properties and was ineffective in vivo. We recently reported that a structural analogue of PhAH, the natural phosphonate antibiotic SF2312, is a high potency inhibitor of Enolase. While more potent than PhAH, SF2312 remains poorly cell permeable. Here, we generated a Pivaloyloxymethyl (POM) ester pro-drug derivative of SF2312, termed POMSF, which increased the potency in cell based systems by ~50-fold. POMSF is selectively active against ENO1-deleted glioma cells in culture at ~19 nM, versus μM for SF2312. However, POMSF displayed poor aqueous stability. A derivative of POMSF, termed POMHEX, showed greater stability and its active form, HEX, showed 4-fold preference for ENO1 over ENO2. Labeled 13C-glucose tracing shows that POMHEX inhibits glycolysis at the Enolase step in all cell lines tested, but with ~100-fold greater potency in ENO1-deleted lines. POMHEX selectively killed ENO1-deleted glioma cells with an IC50 <30nM, whilst non-deleted cells could readily tolerate μM levels of inhibitor. As such, POMHEX was selected for in vivo experiments. Using an orthotopic intracranial xenografted model where tumor growth and response to therapy are monitored by MRI, we show that POMHEX is capable of eradicating intracranial ENO1-deleted tumors, with mice remaining recurrence-free even after treatment discontinuation. Taken together, these results reinforce that glycolysis is a viable target and provide in vivo proof-of-principal for the concept of using passenger deletions as targetable vulnerabilities in personalized cancer therapy.

Citation Format: Yu-Hsi Lin, Nikunj Satani, Naima Hammoudi, Federica Pisaneschi, Paul Leonard, David Maxwell, Zhenghong Peng, Todd Link, Lee IV R. Gilbert, Ananth Bosajou, Duoli Sun, Joe Marszalek, Yuting Sun, John S. McMurray, Pijus K. Mandal, Maria E. Di Francesco, Barbara Czako, Alan Wang, William Bornmann, Ronald A. DePinho, Florian Muller. Pomhex, a cell-permeable high potency enolase inhibitor with utility for collateral lethality treatment of cancer [abstract]. In: Proceedings of the AACR Precision Medicine Series: Opportunities and Challenges of Exploiting Synthetic Lethality in Cancer; Jan 4-7, 2017; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2017;16(10 Suppl):Abstract nr A39.

Off-site Emergency Planning at UK Nuclear Licensed Sites

Nuclear emergency planning arrangements in the UK are continually kept under review. This work proposes to outline how experience from nuclear exercises and undertaking emergency response duties can be based on radiological knowledge of specific sites and utilised in the future. In 2014, the UK regulator, the Office for Nuclear Regulation (ONR) revised their principles for the determination of off-site emergency planning areas around nuclear sites where predetermined countermeasures and other protection measures are applied to protect those people who may be affected by a radiation emergency. The revised principles also enhanced communication from the nuclear site operators and local authorities to the public. This updated ONR's application of the UK Radiation (Emergency Preparedness and Public Information) Regulations 2001 (REPPIR) http://www.hse.gov.uk/radiation/ionising/reppir.htm, which includes details of minimising potential doses to the public, as well as assessment and reassurance, linked to other concurrent risks such as flooding. ONR undertakes site-specific assessments of each operators' hazard identification and risk evaluation, which include consideration of whether the public might receive a significant radiation dose in the year following the emergency (excluding countermeasures in the first 24 hours). In defining the areas for off-site emergency planning, practical and strategic factors are then considered, which include other local non-nuclear emergency planning arrangements and experience, and whether local geographic and demographic aspects could aid public credibility and confidence.

Purification of Antibodies Using Affinity Chromatography

Affinity chromatography permits the isolation of a target analyte from a complex mixture and can be utilized to purify proteins, carbohydrates, drugs, haptens, or any analyte of interest once an affinity pair is available. It involves the exploitation of specific interactions between a binding affinity pair, such as those between an antibody and its associated antigen, or between any ligand and its associated binding receptor/protein. With the discovery of protein A in 1970, and, subsequently protein G and L, immuno-affinity chromatography has grown in popularity and is now the standard methodology for the purification of antibodies which may be implemented for a selection of different applications such as immunodiagnostics. This chapter is designed to inform the researcher about the basic techniques involved in the affinity chromatography-based purification of monoclonal, polyclonal, and recombinant antibodies. Examples are provided for the use of protein A and G. In addition, tables are provided that allow the reader to select the most appropriate protein for use in the isolation of their antibody.

Immunoaffinity Chromatography: Concepts and Applications

Antibody-based separation methods, such as immunoaffinity chromatography (IAC), are powerful purification and isolation techniques. Antibodies isolated using these techniques have proven highly efficient in applications ranging from clinical diagnostics to environmental monitoring. Immunoaffinity chromatography is an efficient antibody separation method which exploits the binding efficiency of a ligand to an antibody. Essential to the successful design of any IAC platform is the optimization of critical experimental parameters such as (a) the biological affinity pair, (b) the matrix support, (c) the immobilization coupling chemistry, and (d) the effective elution conditions. These elements and the practicalities of their use are discussed in detail in this review. At the core of all IAC platforms is the high affinity interactions between antibodies and their related ligands; hence, this review entails a brief introduction to the generation of antibodies for use in immunoaffinity chromatography and also provides specific examples of their potential applications.

Measuring Protein-Protein Interactions Using Biacore

The use of optical biosensors for studying macromolecular interactions is gaining increasing popularity. In one study, 1514 papers that involved the application of biosensor data were identified for the year 2009 alone (Rich and Myszka, J Mol Recognit 24:892-914, 2011), the sheer volume and variety of which present a daunting task for the burgeoning biosensor user to accumulate and decipher. This chapter is designed to provide the reader with the tools necessary to prepare, design, and efficiently execute a kinetic experiment on Biacore. It is written to guide the Biacore user through basic theory, system maintenance, and assay setup while also offering some practical tips that we find useful for Biacore-based studies. Many kinetic-based screening assays require rigorous sample preparation and purification prior to analysis. To highlight these procedures, this protocol describes the kinetic characterization of single chain Fv (scFv) antibody fragments from crude bacterial lysates using an antibody affinity capture approach. Even though we specifically describe the capture of HA-tagged scFv antibody fragments to an anti-HA tag monoclonal antibody-immobilized surface prior to kinetic analysis, the same methodologies are universally applicable and can be used for practically any affinity pair and most Biacore systems.

Identification of potent and selective MTH1 inhibitors

Structure based design of a novel class of aminopyrimidine MTH1 (MutT homolog 1) inhibitors is described. Optimization led to identification of IACS-4759 (compound 5), a sub-nanomolar inhibitor of MTH1 with excellent cell permeability and good metabolic stability in microsomes. This compound robustly inhibited MTH1 activity in cells and proved to be an excellent tool for interrogation of the utility of MTH1 inhibition in the context of oncology.

Abstract C183: Pomhex: a cell-permeable high potency Enolase inhibitor with in vivo anti-neoplastic activity

Glycolysis inhibition is an active area of investigation in cancer. However, few compounds have progressed beyond the cell culture stage. We have recently demonstrated that genomic passenger deletion of the glycolytic enzyme Enolase 1 (ENO1) leaves gliomas harboring such deletions with less than 10% of normal enzymatic activity, rendering them exquisitely sensitive to enolase inhibitors. However, the tool compound that we employed for these in vitro studies, Phosphonoacetohydroxamate (PhAH), has very poor pharmacological properties and was ineffective in vivo. We performed a SAR studies to increase inhibitor specificity towards ENO2 as well as pro-druging to increase cell permeability. The lead compound generated by these efforts, termed POMHEX, is selectively active against ENO1-deleted glioma cells in culture at ∼35nM (versus μM for PhAH). Using an orthotopic intracranial xenografted model where tumor growth and response to therapy are monitored by MRI, we show that POMHEX is capable of eradicating intracranial ENO1-deleted tumors, with mice remaining recurrence-free even after treatment discontinuation. Taken together, these results reinforce that glycolysis is a viable target and provide in vivo proof-of-principal for the concept of using passenger deletions as targetable vulnerabilities in cancer therapy.

Citation Format: Yu-Hsi Lin, Joe Marszalek, Yuting Sun, Naima Hammoudi, Paul Leonard, David Maxwell, Nikunj Satani, Peng Zhang, Todd Link, Gilbert Lee, Maria E. Di Francesco, Barbara Czako, Alan Y. Want, Ronald A. DePinho, Florian L. Muller. Pomhex: a cell-permeable high potency Enolase inhibitor with in vivo anti-neoplastic activity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C183.

Protein engineering with artificial chemical nucleases

The process of protein engineering using artificial chemical nucleases is reported using the Cu(ii)-bis-1,10-phenanthroline complex.

Considerations for the appropriate use of skeletal muscle relaxants for the management of acute low back pain

For patients with low back pain, skeletal muscle relaxants are often initiated after failure of first-line analgesics. However, these medications (reviewed in this article) are controversial alternatives that carry risks of adverse effects and increased cost.

Pediatric pressure injuries: does modifying a tool alter the risk assessment outcome?

The aim of this study was to determine whether assessing patient risk of developing pressure injuries in Pediatric Intensive Care (PICU) and Neonatal Units (NNU) using a modification of the Glamorgan Scale (mGS) would alter the risk identification when compared to the Glamorgan Scale (GS). Prospective data were collected from a convenience sample of patients admitted to PICU or NNU during a 2-month period. The patients' pressure injury risk score using both instruments was collected by observing patients, reviewing patient records, and clarifying information with bedside nurses. Chi square analysis was used to compare the risk category allocations. A total of 133 patients were assessed with complete data available for 112 (PICU = 68, NNU = 65). The total number of admissions during the data collection period was 202 in PICU and 100 in NNU. There was an extensive spread of patients allocated to the "High Risk" and "Very High Risk" categories in both units. Only one was in the lower "At Risk" category. There was little difference in allocated risk category between the mGS and the GS (p = 0.982). Only one patient was not allocated to the same risk category by both tools. In addition to identifying little difference in risk identification the mGS was found to be easier to complete. The mGS delivered the same risk rating as the GS when applied to patients in the PICU and NNU. It is not clear if a similar agreement exists in the general pediatric population. When modifying a validated tool for local use consideration should be given as to how those modifications might alter outcomes.