Rigid bronchoscopy: a consultant survey

INTRODUCTION

Inhalation of foreign bodies represents a potentially fatal emergency in both adults and children. Chest x-ray, in isolation, is neither sensitive nor specific. Rigid bronchoscopy represents the gold standard to diagnose and retrieve paediatric foreign bodies. Cases are encountered infrequently, creating anxieties about their management. Little is known about the confidence in, and maintenance of, rigid bronchoscopy skills by ear, nose and throat teams.

METHODS

A 15-question survey was completed by 50 practising otolaryngology consultants in England.

RESULTS

Results show that almost 40% of otolaryngology consultants covering rigid bronchoscopy have not performed bronchoscopy in more than 5 years. Consultants raised concerns about the anaesthetic support and the speed of equipment assembly. Questions on clinical practice showed disparities in practice in the same scenario.

CONCLUSIONS

The authors advocate addressing many of the issues raised by the study with a greater availability of simulation courses and regular scheduled intradepartmental teaching days for all professionals involved. National guidelines on criteria for transfer to tertiary centres would improve the consistency of practice.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Key aspects of modern GPCR drug discovery

G-protein-coupled receptors (GPCRs) are the largest and most versatile cell surface receptor family with a broad repertoire of ligands and functions. We've learned an enormous amount about discovering drugs of this receptor class since the first GPCR was cloned and expressed in 1986, such that it's now well-recognized that GPCRs are the most successful target class for approved drugs. Here we take the reader through a GPCR drug discovery journey from target to the clinic, highlighting the key learnings, best practices, challenges, trends and insights on discovering drugs that ultimately modulate GPCR function therapeutically in patients. The future of GPCR drug discovery is inspiring, with more desirable drug mechanisms and new technologies enabling the delivery of better and more successful drugs.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Psychological impact of lung cancer screening using a novel antibody blood test followed by imaging: the ECLS randomized controlled trial

BACKGROUND

The Early CDT®-Lung antibody blood test plus serial computed tomography scans for test-positives (TPGs) reduces late-stage lung cancer presentation. This study assessed the psychological outcomes of this approach.

METHODS

Randomized controlled trial (n = 12 208) comparing psychological outcomes 1-12 months post-recruitment in a subsample (n = 1032) of TPG, test-negative (TNG) and control groups (CG).

RESULTS

Compared to TNG, TPG had lower positive affect (difference between means (DBM), 3 months (3m: -1.49 (-2.65, - 0.33)), greater impact of worries (DBM 1m: 0.26 (0.05, 0.47); 3m: 0.28 (0.07, 0.50)), screening distress (DBM 1m: 3.59 (2.28, 4.90); 3m: 2.29 (0.97, 3.61); 6m: 1.94 (0.61, 3.27)), worry about tests (odds ratio (OR) 1m: 5.79 (2.66, 12.63) and more frequent lung cancer worry (OR 1m: 2.52 (1.31, 4.83); 3m: 2.43 (1.26, 4.68); 6m: 2.87 (1.48, 5.60)). Compared to CG, TPG had greater worry about tests (OR 1m: 3.40 (1.69, 6.84)). TNG had lower negative affect (log-transformed DBM 3m: -0.08 (-0.13, -0.02)), higher positive affect (DBM 1m: 1.52 (0.43, 2.61); 3m: 1.43 (0.33, 2.53); 6m: 1.27 (0.17, 2.37)), less impact of worries (DBM 3m: -0.27 (-0.48, -0.07)) and less-frequent lung cancer worry (OR 3m: 0.49 (0.26, 0.92)).

CONCLUSIONS

Negative psychological effects in TPG and positive effects in TNG were short-lived and most differences were small.

Abstract 668: The translational biology of small molecule GPR65 inhibitors: shared effects between mouse models and human primary tumors highlight the unique transformative potential of targeting a genetically validated innate immune checkpoint

Whilst the advent of Immune Checkpoint Blockade has revolutionized the management of cancer, a significant proportion of patients have limited or absent response to these therapies. A key cause of this immune insensitivity is the hostile solid tumor microenvironment (TME) dominated by immunosuppressive myeloid cells. We previously identified the acid sensing G protein coupled receptor (GPCR), GPR65, as a primary determinant of these suppressive cells. In mice, genetic deletion of Gpr65 or oral administration of small molecule GPR65 inhibitors in vivo causes a profound repolarization of immunosuppressive tumor associated macrophages, an increase in infiltrating effector cells and potent anti tumor effects in syngeneic models. In TCGA data, across all tumors, patients homozygous for a hypomorphic coding variant in GPR65 (I231L) show increased overall survival, providing compelling genetic evidence of the clinical potential of GPR65 inhibition. To further explore the translational potential of GPR65 we employed a range of techniques to define the human biology of this receptor in different contexts. At the mechanistic level, single cell RNA sequencing (scRNAseq) of human PBMCs obtained from healthy donors demonstrated a pronounced effect of low pH on the myeloid compartment, with a clear polarization of these cells toward an immunosuppressive character and modulation of GPR65 expression. In parallel, pharmacological inhibition of GPR65 in human monocyte derived macrophages exposed to low pH demonstrated that equivalent gene expression changes are primarily due to GPR65 activation. To examine the relevance of these findings to the intact acidic human TME, we performed studies in fresh primary human tumor histocultures from clear cell renal cell carcinoma (ccRCC) patients with immunohistochemically confirmed high macrophage infiltration and carbonic anhydrase 9 (CA9) expression. In these cultures, GPR65 inhibition caused a dose dependent suppression of a geneset closely overlapping with that modulated by GPR65 in primary macrophages. Furthermore, we observed a marked decrease in immune suppressive IL10 secretion with coincident elevation of specific proinflammatory chemokines. Consistent with these findings, in vivo administration of a small molecule GPR65 inhibitor elicited similar changes in human CA9 expressing RCC PDX tumors implanted in myeloid boosted CD34+ stem cell engrafted NCG mice. In summary, inhibition of GPR65 provides a unique and genetically validated approach to favorably modify the immunosupressive TME with features highly conserved between mouse and human contexts. We propose that GPR65 inhibition holds significant clinical promise, with specific evidence around ccRCC as a potential standout indication.

Citation Format: Barbara Cipriani, Alastair Corbin, David Miller, Alan Naylor, Faraz Khan, Gavin Milne, Barbara Young, Rupert Satchell, Sourav Sarkar, Mussa Quareshy, Anastasia Nika, Preeti Singh, Gavin Knox, Darryl Turner, Satish Sankaran, Nandini Pal Basak, Toszka Bohn, Tobia Bopp, Surya Koturan, Bo Sun, Benjamin Fairfax, Tom McCarthy, Stuart Hughes. The translational biology of small molecule GPR65 inhibitors: shared effects between mouse models and human primary tumors highlight the unique transformative potential of targeting a genetically validated innate immune checkpoint [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 668.

KCTD1 and Scalp-Ear-Nipple ('Finlay-Marks') syndrome may be associated with myopia and Thin basement membrane nephropathy through an effect on the collagen IV α3 and α4 chains

INTRODUCTION

Scalp-Ear-Nipple syndrome is caused by pathogenic KCTD1 variants and characterised by a scalp defect, prominent ears, and rudimentary breasts. We describe here further clinical associations in the eye and kidney.

METHODS

Fifteen affected members from two unrelated families with p.(Ala30Glu) or p.(Pro31Leu) in KCTD1 were examined for ocular and renal abnormalities. The relevant proteins were studied in the eye and kidney, and the mutation consequences determined from mouse knockout models.

RESULTS

Five males and 10 females with a median age of 40 years (range 1-70) with pathogenic variants p.(Ala30Glu) (n = 12) or p.(Pro31Leu) (n = 3) in KCTD1 were studied. Of the 6 who underwent detailed ophthalmic examination, 5 (83%) had low myopic astigmatism, the mean spherical equivalent of 10 eyes was 2.38D, and one (17%) had hypermetropic astigmatism. One female had a divergent strabismus.Five individuals had renal cysts (5/15, 33%), with renal biopsy in one demonstrating a thinned glomerular basement membrane identical to that seen in Thin basement membrane nephropathy (AD Alport syndrome).In the eye, KCTD1 and its downstream targets, TFAP2, and the collagen IV α3 and α4 chains localised to the cornea and near the retinal amacrine cells. In the kidney, all these proteins except TFAP2 were expressed in the podocytes and distal tubules. TFAP2B and COL4A4 knockout mice also had kidney cysts, and COL4A3 and COL4A4 knockout mice had myopia.

CONCLUSION

Individuals with a pathogenic KCTD1 variant may have low myopic astigmatism and represent a further rare genetic cause for a thinned glomerular basement membrane.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Abstract 2162: Inhibition of GPR65 counteracts low pH induced immunosuppressive polarization of macrophages: In vitro and in vivo characterization of potent, selective and orally bioavailable small molecule GPR65 antagonists

The acidic tumour microenvironment (TME) and the abundance of tumour associated macrophages (TAMs) are key features of solid tumours that drive immune suppression, support tumour growth and limit the efficacy of approved therapies. We identified the pH sensing GPCR, GPR65, as a key determinant of low pH induced immune suppression in human cancers, particularly in TAMs, based on the following observations: 1) cancer patients who are homozygous for a hypomorphic coding variant in GPR65 (I231L) show a statistically significant increase in survival and altered expression of key immune system genes compared to other genotypes; 2) single cell RNA sequencing (scRNAseq) data from multiple solid tumors show that GPR65 and downstream pathway genes are ubiquitously expressed in myeloid and other innate immune cells in human cancers; and 3) low pH acting via GPR65 profoundly alters gene expression in human macrophages in vitro, bringing about a pronounced suppression of proinflammatory cytokines and a marked upregulation of tissue repair genes. These findings identify GPR65 as a novel innate immune check point, and suggest that GPR65 inhibition could be highly beneficial in cancer. Indeed, previous work has shown that genetic ablation of the GPR65 signaling pathway in B16.F10 tumour bearing mice upregulates immunostimulatory genes in TAMs and significantly reduces tumor growth1. Pathios has identified potent and selective antagonists of human GPR65 with excellent oral bioavailability and pharmacokinetics. In line with their potencies in recombinant cell systems, lead molecules are able to inhibit low pH induced cAMP elevations in primary human macrophages with IC50 values in the single digit nM range. In macrophages subjected to acidic conditions, the inhibitory effects on cAMP are accompanied by a reduction in the expression of anti inflammatory and tissue repair genes, and the enhancement of immunostimulatory genes. In particular, GPR65 inhibition counteracts the pronounced low pH induced suppression of key Type I/II interferon (IFN) response genes and chemokines such as CXCL9, CXCL10 and CXCL11. Following oral administration in tumour bearing mice, lead compounds up-regulate the expression of anti-tumor immune response genes at systemic exposures that significantly suppress GPR65 signalling in vitro. Results from tumour growth inhibition studies in mice with our GPR65 inhibitors will be also be presented. In summary, ‘Macrophage Conditioning’ via GPR65 inhibition holds substantial promise as a novel immunoncology strategy to counteract the immunosuppressive effects of the acidic TME on TAMs, and could be deployed either as monotherapy or in combination with T cell checkpoint inhibitors or other standard of care treatments. 1Nat. Immunol. 19:1319

Citation Format: Barbara Cipriani, David Miller, Alan Naylor, Gavin Milne, Barbara Young, Rupert Satchell, Suorav Sarkar, Zoe Smith, Rhoanne McPherson, Anastasia Nika, Preeti Singh, Toszka Bohn, Tobias Bopp, Tom McCarthy, Stuart Hughes. Inhibition of GPR65 counteracts low pH induced immunosuppressive polarization of macrophages: In vitro and in vivo characterization of potent, selective and orally bioavailable small molecule GPR65 antagonists [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2162.

825 DEVELOPMENT OF THE ANTICHOLINERGIC MEDICATION INDEX (ACMI)

Introduction

Medications with Anticholinergic (AC) properties, are prescribed to treat a range of conditions. Older people are increasingly likely to be prescribed multiple AC medications, but are also more likely to experience unwanted adverse effects, such as falls and delirium. The risks of adverse outcomes increase with the number and potency of AC medications prescribed. The aim of this study was to use a prognostic modelling approach to develop an AC Medication Index (ACMI) that identifies patients at high risk of AC medication side effects.

Methods

The prognostic model was developed using data on patients aged 65–95 years, registered with a general practice contributing data to ‘Connected Bradford’ in 2019. A Time-dependent Cox model was fitted, with hospital admission for delirium or falls as the composite outcome and AC medications, age, sex and important clinical factors (e.g. dementia, arthritis, urinary incontinence) as predictors. Concordance and Negalkerke’s R2 derived from five-fold cross-validation were used to assess model performance.

Results

There were 151,604 patients included in the study, of whom 47,035 (31.0%) were prescribed ≥1 AC medication during 2019. Codeine, Prednisolone, Furosemide and Amitriptyline were most commonly prescribed with 7.4%, 4.0%, 3.8% and 3.1% of patients prescribed these medications at least once in 2019, respectively. During 2019, 6,078 (4.0%) patients experienced a hospital admission with delirium or a fall, with the rate being increased in those prescribed ≥1 AC medication during 2019 (4.8% vs 3.7%; p &lt; 0.001). The prognostic model yielded a discrimination statistic of 0.86 with an R2 of 0.1.

Conclusion

The model used to develop the ACMI shows good discrimination. External validation will soon be performed using data from the SAIL databank and the ACMI will be further developed as a tool for use in primary care.

Abstract 1631: GPR65 is a critical mediator of low pH induced immunosuppressive signalling in tumor associated macrophages: Human target validation of GPR65 as a novel innate immune checkpoint and discovery of potent, selective GPR65 antagonists

Tumor-associated macrophages (TAMs) are the major innate immune component in the microenvironment of solid tumors. These cells are highly heterogeneous and plastic but often display a pronounced immunosuppressive phenotype that supports primary tumor growth and metastasis. A recently identified determinant of the immunosuppressive properties of TAMs is the activation of the pH-sensing G protein-coupled receptor, GPR65, on these cells by the acidic microenvironment that is inherent to many advanced solid tumours1. Previous work in mouse macrophages has shown that GPR65 activation leads to an elevation of inducible cAMP early repressor (ICER), an isoform of the CREM gene, which in turn suppresses the expression of a host of proinflammatory mediators1. Consistent with a high expression of GPR65 and CREM in human myeloid cells, and particularly in human TAMs, we now show that equivalent immunosuppressive signaling is also present in human macrophages in response to low pH. Further substantiating GPR65 as an innate immune checkpoint in human cancers, we also show that subjects that are homozygous for a hypomorphic coding variant in GPR65 (I231L) have a significantly improved survival across a range of cancers compared to other genotypes. This survival advantage is maintained in patients with highly glycolytic tumors that would otherwise be predicted to respond poorly to immunotherapy, and is consistent with studies showing that genetic deletion of ICER attenuates the growth of anti-PD-1-resistant B16.F10 melanoma tumors in mice1. With a view to developing a therapeutic agent able to reverse low pH-dependent immunosuppression in TAMs, we identified potent and selective small molecule inhibitors of GPR65 from a screening campaign. These molecules were able to fully ablate the acidic pH-induced expression of ICER in human macrophages with downstream implications for pro-inflammatory cytokines known to support T cell anti-tumor responses. Additional medicinal chemistry optimization led to molecules exhibiting excellent oral bioavailability in preclinical species and systemic exposure that completely suppressed GPR65 signaling following oral dosing in mice. Profiling of these inhibitors in relevant mouse tumor models is currently ongoing. In conclusion, we have (i) demonstrated that GPR65 is a key determinant of low pH-induced immunosuppression in human macrophages and thus an important innate immune checkpoint in cancer, and (ii) identified selective small molecule inhibitors of GPR65 with potent in vivo activity. This work provides the basis for developing novel “macrophage conditioning” therapeutic agents that may have utility across a range of cancers, either as single agents or in combination with other approved immunoncology drugs. 1Nat Immunol 19:1319.

Citation Format: Barbara Cipriani, Alan Naylor, Gavin Milne, Barbara Young, Rupert Satchell, Sourav Sarkar, Zoe Smith, Louise Healy, John Unitt, Jessica Holien, Rhoanne McPherson, Anastasia Nika, Jessy Cartier, Tozska Bohn, Tobias Bopp, Tom McCarthy, Stuart Hughes. GPR65 is a critical mediator of low pH induced immunosuppressive signalling in tumor associated macrophages: Human target validation of GPR65 as a novel innate immune checkpoint and discovery of potent, selective GPR65 antagonists [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 1631.

Targeting the p300/CBP Axis in Lethal Prostate Cancer

Resistance to androgen receptor (AR) blockade in castration-resistant prostate cancer (CRPC) is associated with sustained AR signaling, including through alternative splicing of AR (AR-SV). Inhibitors of transcriptional coactivators that regulate AR activity, including the paralog histone acetyltransferase proteins p300 and CBP, are attractive therapeutic targets for lethal prostate cancer. Herein, we validate targeting p300/CBP as a therapeutic strategy for lethal prostate cancer and describe CCS1477, a novel small-molecule inhibitor of the p300/CBP conserved bromodomain. We show that CCS1477 inhibits cell proliferation in prostate cancer cell lines and decreases AR- and C-MYC-regulated gene expression. In AR-SV-driven models, CCS1477 has antitumor activity, regulating AR and C-MYC signaling. Early clinical studies suggest that CCS1477 modulates KLK3 blood levels and regulates CRPC biopsy biomarker expression. Overall, CCS1477 shows promise for the treatment of patients with advanced prostate cancer. SIGNIFICANCE: Treating CRPC remains challenging due to persistent AR signaling. Inhibiting transcriptional AR coactivators is an attractive therapeutic strategy. CCS1477, an inhibitor of p300/CBP, inhibits growth and AR activity in CRPC models, and can affect metastatic CRPC target expression in serial clinical biopsies.See related commentary by Rasool et al., p. 1011.This article is highlighted in the In This Issue feature, p. 995.

Conventional landmark palpation vs. preprocedural ultrasound for neuraxial analgesia and anaesthesia in obstetrics - a systematic review and meta-analysis with trial sequential analyses

The aim of this systematic review and meta-analysis was to examine the efficacy, time taken and the safety of neuraxial blockade performed for obstetric patients with the assistance of preprocedural ultrasound, in comparison with the landmark palpation method. The bibliographic databases Central, CINAHL, EMBASE, Global Health, MEDLINE, Scopus and Web of Science were searched from inception to 13 February 2020 for randomised controlled trials that included pregnant women having neuraxial procedures with preprocedural ultrasound as the intervention and conventional landmark palpation as the comparator. For continuous and dichotomous outcomes, respectively, we calculated the mean difference using the inverse-variance method and the risk ratio with the Mantel-Haenszel method. In all, 22 trials with 2462 patients were included. Confirmed by trial sequential analysis, preprocedural ultrasound increased the first-pass success rate by a risk ratio (95%CI) of 1.46 (1.16-1.82), p = 0.001 in 13 trials with 1253 patients. No evidence of a difference was found in the total time taken between preprocedural ultrasound and landmark palpation, with a mean difference (95%CI) of 50.1 (-13.7 to 113.94) s, p = 0.12 in eight trials with 709 patients. The quality of evidence was graded as low and very low, respectively, for these co-primary outcomes. Sub-group analysis underlined the increased benefit of preprocedural ultrasound for those in whom the neuraxial procedure was predicted to be difficult. Complications, including postpartum back pain and headache, were decreased with preprocedural ultrasound. The adoption of preprocedural ultrasound for neuraxial procedures in obstetrics is recommended and, in the opinion of the authors, should be considered as a standard of care, in view of its potential to increase efficacy and reduce complications without significant prolongation of the total time required.

Core outcome set for uncomplicated acute appendicitis in children and young people

Background

Research studies to inform clinical practice and policy in children and young people with appendicitis are hampered by inconsistent selection and reporting of outcomes. The aim of this study was to develop a core outcome set for reporting all studies of uncomplicated acute appendicitis in children and young people.

Methods

Systematic literature reviews, qualitative interviews with parents and patients treated for uncomplicated acute appendicitis, and a Study‐Specific Advisory Group informed a long list of outcomes. Outcomes were then prioritized by stakeholders based in the UK (patients, parents, and paediatric and general surgeons) in an online three‐round Delphi consensus process, followed by face‐to‐face consensus meetings.

Results

A long list of 40 items was scored by 147 key stakeholders in the first Delphi round, of whom 90 completed the two subsequent Delphi rounds. The final core outcome set comprises 14 outcomes: intra‐abdominal abscess, reoperation (including interventional radiology procedure), readmission to hospital, bowel obstruction, wound infection, antibiotic failure, wound complication, negative appendicectomy, recurrent appendicitis, death, patient stress/psychological distress, length of hospital stay, time away from full activity and child's quality of life.

Conclusion

A core outcome set comprising 14 outcomes across five key domains has been developed for reporting studies in children and young people with uncomplicated acute appendicitis. Further work is required to determine how and when to measure these outcomes.

Effects of the Toll-like receptor 7 (TLR7) agonist, AZD8848, on allergen-induced responses in patients with mild asthma: a double-blind, randomised, parallel-group study

Background

Although allergic asthma is a complex area with many interacting factors involved, the ‘hygiene hypothesis’ proposes that a lack of exposure to infection during childhood may polarise the immune system towards allergen-reactive Th2-type responses in genetically susceptible individuals. Toll-like receptors (TLRs) play a key role within the innate immune system and TLR7 agonists have previously been shown to up-regulate Th1 responses and down-regulate Th2 responses to allergens in murine models of allergic or chronic asthma. This study aimed to examine the efficacy and safety of the novel TRL7 agonist AZD8848, which has been developed as an antedrug.

Methods

In this double-blind, randomised, parallel-group study, AZD8848 60 μg or placebo was administered intranasally once-weekly for 8 weeks in patients with mild-to-moderate allergic asthma (NCT00999466). Efficacy assessments were performed at 1 and 4 weeks after the last dose. The primary outcome was the late asthmatic response (LAR) fall in forced expiratory volume in 1 s (FEV₁) after allergen challenge at 1-week post-treatment.

Results

AZD8848 significantly reduced average LAR fall in FEV₁ by 27% vs. placebo at 1 week after treatment (p = 0.035). This effect was sustained at 4 weeks post-treatment; however, it did not reach clinical significance. AZD8848 reduced post-allergen challenge methacholine-induced airway hyper-responsiveness (AHR) vs. placebo at 1 week post-dosing (treatment ratio: 2.20, p = 0.024), with no effect at 4 weeks. There was no significant difference between the two groups in plasma cytokine, sputum Th2 cytokine or eosinophil responses post-allergen challenge at 1 week after treatment. The incidence of adverse events was similar in the two groups. AZD8848 was generally well tolerated.

Conclusions and clinical relevance

In patients with allergic asthma, TLR7 agonists could potentially reduce allergen responsiveness by stimulating Type 1 interferon responses to down-regulate the dominant Th2 responses.

Trial registration

clinicaltrials.gov identifier NCT00999466.

Recurrent hyperactive ESR1 fusion proteins in endocrine therapy-resistant breast cancer

Background

Estrogen receptor-positive (ER-positive) metastatic breast cancer is often intractable due to endocrine therapy resistance. Although ESR1 promoter switching events have been associated with endocrine-therapy resistance, recurrent ESR1 fusion proteins have yet to be identified in advanced breast cancer.

Patients and methods

To identify genomic structural rearrangements (REs) including gene fusions in acquired resistance, we undertook a multimodal sequencing effort in three breast cancer patient cohorts: (i) mate-pair and/or RNAseq in 6 patient-matched primary-metastatic tumors and 51 metastases, (ii) high coverage (>500×) comprehensive genomic profiling of 287-395 cancer-related genes across 9542 solid tumors (5216 from metastatic disease), and (iii) ultra-high coverage (>5000×) genomic profiling of 62 cancer-related genes in 254 ctDNA samples. In addition to traditional gene fusion detection methods (i.e. discordant reads, split reads), ESR1 REs were detected from targeted sequencing data by applying a novel algorithm (copyshift) that identifies major copy number shifts at rearrangement hotspots.

Results

We identify 88 ESR1 REs across 83 unique patients with direct confirmation of 9 ESR1 fusion proteins (including 2 via immunoblot). ESR1 REs are highly enriched in ER-positive, metastatic disease and co-occur with known ESR1 missense alterations, suggestive of polyclonal resistance. Importantly, all fusions result from a breakpoint in or near ESR1 intron 6 and therefore lack an intact ligand binding domain (LBD). In vitro characterization of three fusions reveals ligand-independence and hyperactivity dependent upon the 3' partner gene. Our lower-bound estimate of ESR1 fusions is at least 1% of metastatic solid breast cancers, the prevalence in ctDNA is at least 10× enriched. We postulate this enrichment may represent secondary resistance to more aggressive endocrine therapies applied to patients with ESR1 LBD missense alterations.

Conclusions

Collectively, these data indicate that N-terminal ESR1 fusions involving exons 6-7 are a recurrent driver of endocrine therapy resistance and are impervious to ER-targeted therapies.

The cost of diabetic foot ulcers and amputations to the National Health Service in England

AIM

To estimate the healthcare costs of diabetic foot disease in England.

METHODS

Patient-level data sets at a national and local level, and evidence from clinical studies, were used to estimate the annual cost of health care for foot ulceration and amputation in people with diabetes in England in 2014-2015.

RESULTS

The cost of health care for ulceration and amputation in diabetes in 2014-2015 is estimated at between £837 million and £962 million; 0.8% to 0.9% of the National Health Service (NHS) budget for England. More than 90% of expenditure was related to ulceration, and 60% was for care in community, outpatient and primary settings. For inpatients, multiple regression analysis suggested that ulceration was associated with a length of stay 8.04 days longer (95% confidence interval 7.65 to 8.42) than that for diabetes admissions without ulceration.

CONCLUSIONS

Diabetic foot care accounts for a substantial proportion of healthcare expenditure in England, more than the combined cost of breast, prostate and lung cancers. Much of this expenditure arises through prolonged and severe ulceration. If the NHS were to reduce the prevalence of diabetic foot ulcers in England by one-third, the gross annual saving would be more than £250 million. Diabetic foot ulceration is a large and growing problem globally, and it is likely that there is potential to improve outcomes and reduce expenditure in many countries.

Abstract 1019: P300/CBP inhibitor CCS1477 targets 22Rv1 prostate tumor AR and c-myc gene expression in vivo

Background: Histone acetyl transferases E1A binding protein (p300) and CREB binding protein (CBP) are known co-activators of several key transcription factors that contribute to tumor progression including HIF1a, BRCA-1, p53, c-myc and androgen receptor (AR). A large proportion of AR regulated gene expression has been shown to be dependent on p300 either through direct regulation of AR interaction with promoters of AR regulated genes or subsequent histone modification events. Both p300 and CBP are highly expressed in advanced prostate cancer and androgen deprivation leads to upregulation of both proteins. CCS1477 is a potent, selective inhibitor of the bromodomain in CBP/p300 that has been shown to inhibit prostate tumor cell proliferation in vitro and tumor growth in vivo.

Methods: 22Rv1 prostate tumor cells that express both AR and AR variants were transplanted in nude mice. Established tumors were treated with CCS1477, 20mg per kg, once daily p.o. for 28 days. CCS1477 treatment resulted in virtually complete inhibition of tumor growth that was maintained up to 24 days after cessation of treatment by which time tumor recurrence was evident. Tumors were excised from vehicle and CCS1477 treated animals at day 7, day 28, and day 52; mRNA was isolated and gene expression analysis was carried using Affymetrix Clarion D microarrays. Differential gene expression based on fold change (FC) &gt;1.5 and FDR-adjusted p-value &lt;0.05 identified a number of genes with significant FC in CCS1477 vs vehicle treated control tumors.

Results: Although ~1.5 fold downregulation of AR was maintained from day 7 to day 52, downregulation of AR target genes ETS2, TMPRSS2 and NKX3.1 recovered after treatment cessation. Similarly, expression of c-myc was significantly reduced at day 7 (-2.7 FC) and recovered by day 28. Of note, among the top downregulated genes were CIART and BHLHE40 circadian clock regulated genes that provide negative feedback loops that in conjunction with downregulation of AR and c-myc would disrupt circadian gene regulation. VEGFA mRNA that was downregulated &gt;1.5 fold at all time points, together with c-myc and p300 are all under circadian regulation. Expression of the histone demethylase KDM3A was reduced &gt;1.5 fold at all time points. KDM3A is known to function as an AR coactivator of key AR target genes including NKX3.1 and c-myc.

Conclusions: Gene expression analysis of CCS1477 treated prostate tumors suggests an underlying mechanism involving the inhibition of key drivers of prostate cancer progression including AR and c-myc and a network of interacting pathways.

Citation Format: Paul Elvin, Neil Pegg, Simone Daminelli, Izabela Eden, Barbara Young, Amy Prosser, Jenny Worthington, Nigel Brooks. P300/CBP inhibitor CCS1477 targets 22Rv1 prostate tumor AR and c-myc gene expression in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1019.

Abstract 3826: CCS1477, a potent and selective p300/CBP bromodomain inhibitor, is targeted & differentiated from BET inhibitors in prostate cancer cell lines in vitro

Background: CCS1477 is a potent and selective p300/CBP bromodomain inhibitor, currently in a Ph1 trial for patients with metastatic castration resistant prostate cancer (mCRPC). CCS1477 works by inhibiting the expression and function of the androgen receptor (AR), as well as inhibiting c-Myc. Bromodomain and extraterminal domain (BET) protein inhibitors are also being developed in mCRPC. We have established a BET inhibitor (BETi) resistant 22Rv1 prostate cancer cell line and used this, alongside parental 22Rv1 cells, to characterise the differential effects of p300/CBP vs BET bromodomain inhibition.

Methods: 22Rv1 cells which express both the wild-type and splice variant forms of AR were cultured in the presence of increasing concentrations (30-500nM) of JQ1 for several months. A parallel set of 22Rv1 cells were cultured in the presence of vehicle (0.1% DMSO). The anti-proliferative effects of JQ1, iBet762, OTX-015 and CCS1477 (10 nm-10 µM dose range) was determined in resistant and parental 22Rv1 cells in a 5d CellTitre Glo assay. The effects of combining CCS1477 with JQ1 was measured in parental 22Rv1 cells. Protein biomarker (AR, AR-splice variant, c-Myc) responses were measured by Western blot and qPCR was used to determine changes in the expression of selected genes (AR, AR-V7, c-Myc, KLK3, TMPRSS2). Gene expression microarrays (Clariom D) were used to assess global gene expression changes in cells treated for 24h with 500nM CCS1477 or JQ1.

Results: JQ1 resistant 22Rv1 cells were significantly less sensitive to JQ1 compared with parental cells. (IC50; Res, 7.3 µM vs parental, 0.06 µM). There was also cross-resistance to other chemically distinct BET inhibitors, iBET762 and OTX-015. JQ1 potently inhibited c-Myc protein and gene expression in parental cells, a response that was abrogated in the JQ1 resistant line. The inhibitory effects of JQ1 on AR gene and protein expression were reduced in the resistant line. In contrast potent anti-proliferative effects of CCS1477 were retained in JQ1 resistant cells, as was the inhibitory effect on c-Myc and AR. Combination of CCS1477 & JQ1 resulted in a highly synergistic inhibitory effect on proliferation in normal 22Rv1 cells. Global gene expression analysis revealed significantly fewer altered genes after CCS1477 (27 up, 119 down) compared to JQ1 (196 up, 655 down).

Conclusions: These studies provide three lines of evidence for a differentiated mode of action of CCS1477 vs BETi. First, CCS1477 continues to inhibit proliferation and relevant response biomarkers in a cell line that is resistant to BETi. Second, there is a synergistic, rather than additive effect of combining CCS1477 with JQ1. Third, there are significantly fewer genes and a distinct pattern of gene change after CCS1477 vs. JQ1. Collectively, these data point to a differentiated and more selective profile after p300/CBP inhibition with CCS1477.

Citation Format: Nigel Brooks, Amy Prosser, Barbara Young, Luke Gaughan, Paul Elvin, Neil Pegg. CCS1477, a potent and selective p300/CBP bromodomain inhibitor, is targeted & differentiated from BET inhibitors in prostate cancer cell lines in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3826.

Treatment preference and recruitment to pediatric RCTs: A systematic review

BACKGROUND

Recruitment to pediatric randomised controlled trials (RCTs) can be a challenge, with ethical issues surrounding assent and consent. Pediatric RCTs frequently recruit from a smaller pool of patients making adequate recruitment difficult. One factor which influences recruitment and retention in pediatric trials is patient and parent preferences for treatment.

PURPOSE

To systematically review pediatric RCTs reporting treatment preference.

METHODS

Database searches included: MEDLINE, CINAHL, EMBASE, and COCHRANE.Qualitative or quantitative papers were eligible if they reported: pediatric population, (0-17 years) recruited to an RCT and reported treatment preference for all or some of the participants/parents in any clinical area. Data extraction included: Number of eligible participants consenting to randomisation arms, number of eligible patients not randomised because of treatment preference, and any further information reported on preferences (e.g., if parent preference was different from child).

RESULTS

Fifty-two studies were included. The number of eligible families declining participation in an RCT because of preference for treatment varied widely (between 2 and 70%) in feasibility, conventional and preference trial designs. Some families consented to trial involvement despite having preferences for a specific treatment. Data relating to 'participant flow and recruitment' was not always reported consistently, therefore numbers who were lost to follow-up or withdrew due to preference could not be extracted.

CONCLUSIONS

Families often have treatment preferences which may affect trial recruitment. Whilst children appear to hold treatment preferences, this is rarely reported. Further investigation is needed to understand the reasons for preference and the impact preference has on RCT recruitment, retention and outcome.

Abstract A091: Therapeutic targeting of the p300/CBP bromodomain for the treatment of castration-resistant prostate cancer

Background: Sustained androgen receptor pathway activation is the hallmark of castration-resistant prostate cancer (CRPC). Therapeutic strategies for CRPC include non-ligand-binding domain targeted degradation of androgen receptor (AR) and AR variants (ARV). E1A binding protein (p300) and CREB binding protein (CBP) are two closely related histone acetyl transferase proteins that are critical transcriptional regulators of the androgen receptor. We have developed CCS1477, which is a potent, selective, and orally active small-molecule inhibitor of the bromodomain of p300/CBP, and investigated its role in regulating androgen receptor expression and function.

Methods: Binding affinity of CCS1477 to p300, CBP and BRD4 was measured in a surface plasmon resonance (SPR) assay. Potency and functional activity (proliferation, cell cycle analysis, and biomarker knockdown) was demonstrated in a panel of prostate cells lines representing hormone-responsive (LNCaP), hormone-independent (DU145, PC3), and castration-resistant disease (22Rv1, VCaP, LNCaP-AR). A JQ1 resistant cell line was generated by culturing cells in increasing doses of JQ1 over a period of approximately 9 months and used to differentiate potency and functional activity of BET vs p300/CBP inhibition in vitro. In vivo efficacy, linked to inhibition of biomarkers, was determined in 22Rv1 and LNCaP xenograft models.

Results: CCS1477 binds to p300 and CBP with high affinity (KD=1.3/1.7nM) and selectivity (KD=222nM; BRD4). It is a potent inhibitor of cell proliferation in castration-resistant cell lines (IC50= 96nM,22Rv1; 49nM,VCaP; 150nM,LNCaP-AR) with minimal effect in AR-ve lines (PC3, DU145). These inhibitory effects on cell proliferation were accompanied by a decrease in the number of cells in S phase and an increase in the number of cells in the G1/G0 phase of the cell cycle. We have developed a JQ1 resistant 22Rv1 cell line and observed a marked reduction in sensitivity (proliferation end point) to JQ1 as expected, which is accompanied by cross-resistance to a variety of other BET inhibitors, including iBET-151 and OTX-015. In contrast, and as evidence for a differentiated mechanism, sensitivity to CCS1477 is retained in this JQ1 resistant line. Inhibition of the bromodomain of p300/CBP downregulates AR-FL, AR-V7 and c-Myc protein in 22Rv1 cells by Western blot and this is accompanied by profound inhibition of c-Myc, KLK3 and TMPRSS2 genes measured by qPCR. The in vivo PK properties of CCS1477 are consistent with qd or qod oral dosing in mouse. CCS1477 dosed at 10mg/kg qd, 20mg/kg qd, or 30mg/kg qod caused complete tumor growth inhibition over 28 days in a 22Rv1 xenograft model, including extended duration in the absence of the drug for a further 24 days. This was accompanied by complete inhibition of plasma PSA and significant knockdown of tumor AR-FL, AR-V7, and c-Myc protein as well as c-Myc and TMPRSS2 mRNA expression. At 100mg/kg, a single dose of CCS1477 induces expression of cleaved PARP and when dosed orally every three days, causes tumor regression in the 22Rv1 model. Furthermore, CCS1477 results in almost complete tumor growth inhibition in a bicalutamide-resistant LNCaP xenograft model, when given alone or in combination with enzalutamide.

Conclusions: Taken together, these data support the concept that therapeutic targeting of the p300/CBP bromodomain results in a novel and differentiated approach to targeting androgen receptor pathway activation in castration-resistant prostate cancer.

Citation Format: Nigel Brooks, Neil Pegg, Jenny Worthington, Barbara Young, Amy Prosser. Therapeutic targeting of the p300/CBP bromodomain for the treatment of castration-resistant prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A091.

Abstract 3991: Novel small molecule inhibitors of p300/CBP down-regulate androgen receptor (AR) and c-Myc for the treatment of prostate cancer and beyond

Background: E1A binding protein (p300) and CREB binding protein (CBP), two paralogue histone acetyl transferase proteins, act as transcriptional co-activators of a variety of cancer related genes. We have developed CCS1477, a potent, selective and orally active small molecule inhibitor of the bromodomain of p300/CBP and investigated its role in regulating AR and c-Myc expression and function, for the treatment of prostate cancer and haematological malignancies. We have also examined the role of p300/CBP in driving synthetic lethality in tumours with loss of function mutations (eg. bladder cancer).

Methods: Potency and functional activity was evaluated in a panel of prostate cells lines representing hormone responsive, hormone independent and castration resistant disease. Effects of CCS1477 on AR, AR-V7 splice variant and c-Myc protein, as well as KLK3, c-Myc, UBE2C, CCNA2 and TMPRSS2 gene expression, were assessed. Inhibition of proliferation and function by CCS1477 was also examined in acute myeloid leukaemia cell lines and patient derived primary AML cells. In addition, potency was determined in bladder cell lines possessing a loss of function mutation in p300/CBP and compared to wild type.

Results: CCS1477 is a potent inhibitor of cell proliferation in castration resistant prostate cell lines (IC50 = 96nM 22Rv1; 49nM VCaP) with minimal effect in AR-ve lines (PC3 and DU145). Treatment of 22Rv1 and VCaP cells with CCS1477 significantly reduced expression of KLK3, UBE2C and CCNA2 in the presence and absence of enzalutamide indicating compromised signalling via AR and AR-SV. Furthermore, AR and AR-SV protein levels were inhibited in response to CCS1477 treatment. Utilising an enzalutamide-resistant cell line (LNCaP-ARF876L), CCS1477 treatment down-regulated both androgen and enzalutamide-stimulated KLK3 and TMPRSS2 gene expression. CCS1477 dosed at 20mg/kg qd caused complete tumour growth inhibition in a 22Rv1 xenograft model. CCS1477 is also a potent inhibitor of proliferation in AML cell lines (IC50 ~ 100nM; THP-1; MV4-11), with effects mediated by G1 cell cycle arrest and accompanied by myeloid differentiation. Comparable results are observed on patient derived primary AML cells. In bladder cancer cell lines, we observed differential sensitivity to CCS1477 with p300/CBP deficient lines (IC50 = 300nM VM-CUB-2 and 647V) compared with wild type (no activity at 30uM, RT112).

Conclusions: Taken together these data support the clinical testing of p300/CBP inhibition in patients in three settings; (i) castration resistant prostate cancer through down-regulating AR, AR-SV and c-Myc expression and function; (ii) haematological cancers by effects on cell cycle arrest and myeloid differentiation, and (iii) patients with loss of function mutations in p300 or CBP by driving synthetic lethality.

Citation Format: Neil Pegg, Jenny Worthington, Barbara Young, Amy Prosser, Luke Gaughan, Gary Spencer, Tim Somervaille, Julie Burns, Margaret Knowles, Nigel Brooks. Novel small molecule inhibitors of p300/CBP down-regulate androgen receptor (AR) and c-Myc for the treatment of prostate cancer and beyond [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 3991.

Antiretroviral nonadherence and condomless sex in the HIV Outpatient Study, USA, 2007-2014

Effective antiretroviral therapy (ART) reduces plasma HIV RNA viral load (VL) to undetectable levels and its effectiveness depends on consistent adherence. Consistent adherence and use of safe sex practices may substantially decrease the risk of HIV transmission. We sought to explore the potential association between self-reported nonadherence to ART and engaging in unsafe sexual practices capable of transmitting HIV. Using clinical and audio computer-assisted self-interview data from the prospective HIV Outpatient Study from 2007 to 2014, we assessed the frequency of self-reported ART nonadherence during the three days prior to the survey among HIV-infected persons in care and factors associated with self-reported ART nonadherence. Of 1729 patients included in this analysis (median age = 48 years, 74.3% men who have sex with men), 17% were nonadherent, 15% had a detectable VL, and 42% reported condomless anal or vaginal sex in the past six months. In multivariable analysis, self-reported nonadherence was independently associated with younger age (adjusted odds ratio [aOR] 0.8 per additional ten years, [95% CI] 0.7-1.0), non-Hispanic black race/ethnicity (aOR 1.9; 95% CI 1.4-2.6 versus white), public health insurance (aOR 1.6, 95% CI 1.2-2.3 compared with private), survey date in 2011-2014 versus 2007-2010 (aOR 0.7, 95% CI 0.5-0.9), CD4 cell count ≥ 500 versus < 200 cells/mm³ (aOR 0.3, 95% CI 0.2-0.5), greater number of ART regimen doses (aOR 1.6, 95% CI 1.3-2.2), and binge drinking (aOR 1.4, 95% CI, 1.1-1.9). In this analysis, self-reported nonadherence was not associated with engaging in condomless sex.

Abstract 1575: Novel small molecule inhibitors of p300/CBP down-regulate AR and c-Myc for the treatment of castrate resistant prostate cancer

Background: E1A binding protein (p300) and CREB binding protein (CBP) are two closely related, paralogue histone acetyl transferase proteins that act as transcriptional co-activators of a variety of cancer related genes. We have developed potent, selective and orally active small molecule inhibitors of the bromodomain of p300/CBP and investigated their role in regulating androgen receptor expression and function. We have also examined their role in driving synthetic lethality in tumours. Loss of function mutations in either p300 or CBP (including in significant proportions of lung and bladder tumours), can lead to a dependency on the corresponding paralogue protein.

Methods: Binding affinity to p300, CBP and BRD4 was measured in a surface plasmon resonance (SPR) assay. Potency and functional activity was demonstrated in a panel of prostate cells lines representing hormone responsive (LNCaP), hormone independent (DU145, PC3) and castrate resistant disease (22Rv1, C4-2, VCaP, LNCaP-AR) as well as wildtype (A549) and CBP deficient (H520, H1703, LK2) lung cancer cells. Combination effects of p300/CBP inhibitors with a PARP or CDK4/6 inhibitor were determined in LNCaP and C4-2 cells. Effects of p300/CBP inhibitors (and by comparison, the BET inhibitor, JQ1), on AR, AR-V7 splice variant and c-Myc protein, as well as c-Myc, KLK3 and TMPRSS2 gene expression, were assessed in 22Rv1 cells in vitro. In vivo effects on biomarkers were measured in a 22Rv1 xenograft model.

Results: CCS1357, an in vitro probe compound, binds to p300 and CBP with high affinity (Kd=4nM) and selectivity (Kd=245nM; BRD4). It is a potent inhibitor of cell proliferation in castrate resistant cell lines (IC50=100nM in LnCaP-AR; 350nM in 22Rv1) with minimal effects in hormone independent lines. CCS1357 combined with palbociclib (CDK4/6) or olaparib (PARP) in LNCaP or C4-2 cells, showed reduced cell viability compared with any of these drugs given alone. In 22RV1 cells, CCS1357 significantly down-regulated AR-FL, AR-V7 and c-Myc protein by Western, an effect not seen with JQ1 at equivalent proliferation IC50s. CCS1357 effects were reversed by the proteasome inhibitor, MG132. CCS1357 also caused a profound inhibition of c-Myc, KLK3 and TMPRSS2 genes measured by qPCR in 22Rv1 cells in vitro. A preclinical candidate (CCS1477) given as a single oral dose (30mg/kg) inhibited plasma PSA and tumour AR, AR-V7 and c-Myc in a 22Rv1 xenograft model. In the lung cancer cell lines, we observed differential sensitivity to CCS1357; CBP deficient lines were more sensitive (cell proliferation) compared with normal.

Conclusions: Taken together these data support the clinical testing of p300/CBP inhibition in patients in two settings; firstly, castrate resistant prostate cancer by down-regulating of AR, AR-SV and c-MYC expression and function; and secondly in patients with loss of function mutations in p300 or CBP by driving synthetic lethality.

Citation Format: Nigel Brooks, Neil Pegg, Jenny Worthington, Barbara Young, Amy Prosser, Jordan Lane, David Taddei, Matthew Schiewer, Renee deLeeuw, Jennifer McCann, Karen Knusden. Novel small molecule inhibitors of p300/CBP down-regulate AR and c-Myc for the treatment of castrate resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1575. doi:10.1158/1538-7445.AM2017-1575

Communication with young people in paediatric and adult endocrine consultations: an intervention development and feasibility study

BACKGROUND

Communication is complex in endocrine care, particularly during transition from paediatric to adult services. The aims of this study were to examine the feasibility of interventions to support young people to interact with clinicians.

METHODS

Development and evaluation of a complex intervention in 2 phases: Pre-intervention observational study; Intervention feasibility study. Purposive sample of recordings of 62 consultations with 58 young people aged 11-25 years with long-term endocrine conditions in two paediatric and two adult endocrine clinics. Proportion of time talked during consultations, number and direction of questions asked; Paediatric Consultation Assessment Tool (PCAT); OPTION shared decision making tool; Medical Information Satisfaction Scale (MISS- 21). Young people were invited to use one or more of: a prompt sheet to help them influence consultation agendas and raise questions; a summary sheet to record key information; and the www.explain.me.uk website.

RESULTS

Nearly two thirds of young people (63%) chose to use at least one communication intervention. Higher ratings for two PCAT items (95% CI 0.0 to 1.1 and 0.1 to 1.7) suggest interventions can support consultation skills. A higher proportion of accompanying persons (83%) than young people (64%) directed questions to clinicians. The proportion of young people asking questions was higher (84%) in the intervention phase than in the observation phase (71%).

CONCLUSIONS

Interventions were acceptable and feasible. The Intervention phase was associated with YP asking more questions, which implies that the availability of interventions could promote interactivity.

Characterisation of CCS1477: A novel small molecule inhibitor of p300/CBP for the treatment of castration resistant prostate cancer

11590

Background: Targeted degradation of androgen receptor (AR) and AR variants (ARV) remains an attractive therapeutic opportunity for patients with castrate resistant prostate cancer (CRPC). E1A binding protein (p300) and CREB binding protein (CBP) are two closely related transcriptional activators of AR. We have developed CCS1477 which is a potent, selective and orally active small molecule inhibitor of the bromodomain of p300/CBP and investigated its role in regulating androgen receptor expression and function. Methods: Binding of CCS1477 to p300, CBP and BRD4, was measured in a surface plasmon resonance (SPR) assay. Potency and functional activity (proliferation and biomarker knockdown) was demonstrated in prostate cell lines in vitro (22Rv1, VCaP). Cross species in vivo pharmacokinetic (PK) properties were assessed, and in vivo efficacy, linked to inhibition of biomarkers, was determined in 22Rv1 and LNCaP xenograft models. Results: CCS1477 binds to p300 and CBP with high affinity (Kd = 1.3/1.7nM) and selectivity (Kd = 222nM; BRD4). It is a potent inhibitor of cell proliferation in prostate cell lines (IC50 = 96nM,22Rv1; 49nM,VCaP) with minimal effect in AR-ve lines. In 22Rv1 cells, p300/CBP inhibition down-regulates AR-FL, AR-V7 and c-Myc protein by Western, an effect not seen with the BET inhibitor, JQ1 at equivalent proliferation IC50s. Inhibition of p300/CBP also reduces c-Myc, KLK3 and TMPRSS2 gene expression (qPCR) in 22Rv1 cells in vitro. The in vivo PK properties of CCS1477 are consistent with qd or qod oral dosing in mouse. CCS1477 dosed at 10mg, 20mg/kg qd or 30mg/kg qod, caused complete tumour growth inhibition over 28 days in a 22RV1 xenograft model, including extended duration in the absence of the drug for a further 24 days. This was accompanied by complete inhibition of plasma PSA and significant knockdown of tumour AR-FL, AR-V7, and C-Myc protein as well as C-Myc and TMPRSS2 mRNA expression. Conclusions: Taken together these data support the clinical testing of CCS1477 in castrate resistant prostate cancer by down-regulation of AR, AR-SV and c-MYC expression and function.

A novel small molecule inhibitor of p300/CBP for the treatment of castration-resistant prostate cancer: Preclinical evaluation

168

Background: Targeted degradation of androgen receptor (AR) and androgen receptor variants (ARV) remains an attractive therapeutic opportunity for patients with castrate resistant prostate cancer (CRPC). E1A binding protein (p300) and CREB binding protein (CBP) are two closely related histone acetyl transferase proteins that act as transcriptional activators of AR. We have developed potent, selective and orally active small molecule inhibitors of the bromodomain of p300/CBP and investigated their role in regulating the expression and function of AR and ARV. Methods: Binding affinity to p300, CBP and BRD4 was measured in a surface plasmon resonance (SPR) assay and potency and functional activity was demonstrated in a panel of prostate cells lines representing hormone responsive (LNCaP), hormone independent (DU145, PC3) and castrate resistant disease (22Rv1, C4-2, VCaP, LNCaP-AR). Effects of p300/CBP inhibitors (and the BET inhibitor, JQ1), on AR, AR-V7 splice variant and c-Myc protein, as well as c-Myc, KLK3 and TMPRSS2 gene expression, were assessed in 22Rv1 cells in vitro. In vivoeffects on biomarkers were measured in a 22Rv1 xenograft model. Results: CCS1357, an in vitro probe compound, binds to p300 and CBP with high affinity (Kd=4nM) and selectivity (Kd=245nM; BRD4) and is a potent inhibitor of cell proliferation in castrate resistant cell lines (IC50=100nM in LnCaP-AR; 350nM in 22Rv1) with minimal effects in hormone independent lines. CCS1357 significantly down-regulated AR-FL, AR-V7 and c-Myc protein by Western, an effect not seen with JQ1 at equivalent proliferation IC50s. CCS1357 effects were reversed by the proteasome inhibitor, MG132. CCS1357 also caused a profound inhibition of c-Myc, KLK3 and TMPRSS2 genes measured by qPCR in 22Rv1 cells in vitro. A preclinical candidate (CCS1477) given as a single oral dose (30mg/kg) inhibited plasma PSA and tumour AR and AR-V7 in a 22Rv1 xenograft model. Conclusions: Small molecule inhibition of the bromodomain of p300/CBP, leads to down-regulation of AR, ARV and c-Myc as well as inhibition of key downstream PD biomarkers including PSA and TMPRSS2 and represents a promising new approach for the treatment of CRPC.

Abstract P1-05-23: Utilities and challenges of RNA-Seq based expression and variant calling in a clinical setting

Introduction

Variant calling based on DNA samples has been the gold standard of clinical testing since the advent of Sanger sequencing. The use of DNA variants has proved a great value to guide treatment in cancer patients. However, DNA based analysis will not inform about expression status of the gene harboring a particular variant. RNA has long been used to monitor expression. To this point RNA assays and analysis are confined to the research laboratory and rarely used clinically except in specifically defined gene signatures such as PAM50 and OncoType Dx. Beyond expression, RNA has the ability to confirm expression of DNA variants and identify fusion events. We hypothesize that the combination of DNA and RNA based data will allow the determination of variant specific expression status and improve clinical diagnostics. It has been previously shown that RNA sequencing (RNA-Seq) based variant calls are highly accurate and confirm DNA based variant calls. In this study we investigated the utility of RNA-Seq as a diagnostic assay integrated with DNA based sequencing data.

Materials and Methods

Targeted DNA sequencing of 321 genes was performed on 37 patient samples (FFPE), including 22 breast cancer samples by a commercial vendor. RNA-Seq on the same patient samples was performed using 100ng of total RNA. Libraries were run on the Illumina NextSeq 500 with a minimum of 75M paired 75bp reads. To evaluate RNA-seq expression reproducibility, replicates of 6 normal ovarian tissue samples (min. 50M reads) were run in sets of triplicates. STAR was used for alignment (hg19) and gene expression quantification (RefSeq). RNA-Seq based variant calling was performed using the SNPiR pipeline. Based on the results of the commercial assay, DNA based variants were examined for expression of the corresponding genes and ability to confirm variants in the RNA-Seq data.

Results

RNA expression data showed no corresponding gene expression for at least one single nucleotide variant (SNV) in 9/37 patients analyzed (24.3%). In 18/37 patients (48.6%) SNV corresponding expression was in the lowest quartile of expression values. Variant calls could be confirmed by RNA-Seq for 95/455 SNVs, with adequate coverage in 263 of the remaining 360 variant locations (median coverage: 34). Of these, a homozygous reference call was made in 166/263 SNVs. Concordance for RNA-Seq gene level expression data between replicates was &gt; 0.995.

Conclusions

These findings suggest that RNA-Seq based data can provide clinical value when using gene expression values in combination with DNA based variant calls. We found gene level expression to be highly reproducible and will further investigate the use of spike in controls to determine clinically usable expression ranges and lower limit of expression values. To our knowledge, it has not been shown that RNA-Seq based variant calls are reproducible which is the focus of our current research as this will be one requirement for usage in a regulated environment. While our use of RNA Seq is currently limited to gene expression level data, we have demonstrated a clinically relevant benefit to using RNA Seq data as an additive feature to the current standard of DNA variant calling.

Citation Format: Young B, Mark A, Meissner T, Amallraja A, Andrews A, Connolly C, Williams C, Leyland-Jones B. Utilities and challenges of RNA-Seq based expression and variant calling in a clinical setting [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-23.

Abstract P3-03-06: Characterization of HER2-positive breast cancer (BC) cells selected for tolerance to trastuzumab-induced antibody-dependent cell-mediated cytotoxicity (ADCC)

Cellular mechanisms of trastuzumab resistance include alteration(s) in cell signaling pathways (PTEN loss, activation of PI3K/Akt signaling), steric hindrance of antibody binding (by Muc-1/Muc-3), over-activation of alternate receptor kinases (HER3/c-Met/IGF-1R), and proteolysis of HER2 extracellular domain harboring target epitopes for antibody-based therapeutics. Prior studies of trastuzumab resistance have focused largely on cells selected ex vivo with the antibody in absence of human immune effector cells. We developed a selection model, wherein human HER2 positive BC cells (BT474, SKBR3) were subjected to acute ADCC (&gt;90% cell death), trastuzumab concentration 100ug/mL, effector-target ratio 100:1, using human peripheral blood mononuclear cells (PBMCs) as effectors. Surviving cells were allowed to recover to confluence over 8-10 weeks, for 10 total rounds of ADCC selection ex vivo. Mock-treated parent, IgG1 isotype control, trastuzumab, and PBMCs alone were used as controls. ADCC assays based on calcein fluorescent labeling of live target cells, revealed significant reduction (maximum 20%, p&lt;0.005) in cell lysis in immune-selected BT474 cell lines compared to parental controls (immune-selected SKBR3 cells exhibited a non-significant trend towards reduced ADCC). Transcriptome-wide next-generation RNA sequencing (Illumina NextSeq 500, 2 x 75 bp paired-end, median of 46 million paired-end reads/sample), coupled with pathway enrichment analysis (Reactome), followed by q-PCR validation, confirmed significant changes in expression in immune-selected cells (compared to parent control) for genes including: ALDH1, ANK1, TMPRSS3, HINT1, DNM2, TNNC1, COL4A4 in BT474; and ALDH1, ANK1, CAMP1, CPE, IDO1 in SKBR3 cells. Whole-genome sequencing (Illumina HiSeq X, 150 bp paired end, 30x coverage) elucidated 180 genes with single nucleotide variations (SNVs) in immune-selected cells compared to parent in BT474 cells, and 215 genes in SKBR3 cells. Thirty-four SNVs were shared in both cell lines. Further screening and validation confirm genes with SNVs demonstrating significant transcript up-regulation. These include: COL4A3, LEP, SOX-9 in BT474; and HLA-B, TNFRSF10B, HLA-B, PSMA6 in SKBR3. In further phenotypic analysis, ADCC-conditioned BT474 cells exhibit an elongated fibroblast-like morphology with multiple processes, in contrast to control. Immune-selected SKBR3 cells (and not BT474 cells) demonstrate significantly increased motility compared to control in transwell migration assays (p&lt;0.001), and demonstrated increased cell proliferation (MTT assay, 10-15%, 48h; p=0.0242) as compared to parent controls. Our data indicate immune-selection by effector cells contributes to ADCC tolerance in vitro, and is associated with distinct genotypic and phenotypic alterations. Future investigation will determine whether Fc-engineered MAbs (afucosylated), antibody drug conjugates (T-DM1), or potentiation of ADCC by co-stimulatory agonist CD137 antibodies will re-sensitize ADCC-tolerance. This investigation will help to elucidate potentially targetable pathways that emerge from immune-selection with trastuzumab.

Citation Format: Biswas T, Fritzemeier R, Mark A, Meißner T, Young B, Jones BL, Pegram M. Characterization of HER2-positive breast cancer (BC) cells selected for tolerance to trastuzumab-induced antibody-dependent cell-mediated cytotoxicity (ADCC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-03-06.

Abstract P1-05-22: The value of RNA-Seq for the detection of clinically actionable targets in breast cancer - A small cohort analysis

Introduction

Next generation sequencing has facilitated the understanding of pathogenesis and molecular heterogeneity of breast cancer (BC) as well as accelerated the path towards precision medicine. DNA sequencing (DNA-Seq) based assays for the detection of mutations and alterations in solid and hematologic cancers are finding their way into clinical practice and are readily available as clinical products. RNA sequencing (RNA-Seq), so far being vastly applied in the research context, promises to expand the diagnostic, prognostic and therapeutic use of this technology in cancer. Beyond mutational status, RNA-Seq enables the detection of fusions, quantification of gene expression level, detection of differentially expressed genes, molecular based subtyping, and risk-stratification. In this study we analyzed RNA-Seq and copy number data from BC patients that had undergone DNA-Seq based diagnostics through commercial providers with the goal to detect additional actionable targets.

Materials and Methods

We included 18 BC patients (5/18 triple negative) that had previously undergone DNA-based targeted (321 genes) sequencing. RNA-Seq to a minimum of 75M reads (75pb) was performed using 100 ng of total RNA on the Illumina NextSeq 500 platform. STAR was used for alignment (hg19) and gene expression quantification (RefSeq). Fusions were detected using STAR-Fusion. DESeq2 was utilized to identify patient specific differentially expressed genes by analyzing samples individually against a set of 13 controls from healthy breast tissue generated in-house. Copy number variations (CNVs) were detected using the Nanostring CNV Cancer panel (89 genes) on the Nanostring nCounter platform. Differentially upregulated or amplified genes were queried against DGIdb and Gene Drug Knowledge database for suitable drug matches, limiting the queries to clinically actionable antineoplastic drugs.

Results

Analyzing the cohort of 18 BC patients, we detected on average 26 BC relevant genes (526 total, log2 FC &gt; 2) to be upregulated per patient. Querying the upregulated genes against DGIdb, we found a total of 18 genes that had drug matches and fulfilled the criteria of being actionable antineoplastic drugs, with 17/18 samples having a minimum of two gene targets (avg: 4). Most frequent upregulated genes were TOP2A (83%), AURKA (61%), AURKB (56%), RET (39%)and FGFR3 (28%). In the case of CNVs, 12/18 patients showed at least one gene target with clinically actionable drugs associated. This was observed across 12 gene targets that were amplified (avg: 3) and 4 gene targets that underwent deletions (avg: 1). Most frequent CNVs included MYC (14%) and CCND1 (12%). 4/7 patients having an AURKA overexpression also showed an AURKA amplification on the CNV assay. 10/18 patients had fusions events, with an average of three fusions per patient, including GAB2-WNT11, PAK1-TENM4 and FGFR2-CEP55 fusions.

Conclusions

We show that RNA-Seq and copy number assays provide additional clinical value by detecting suitable drug targets beyond traditional DNA-based approaches. We are conducting further analysis on how these additionally derived drug targets could improve the current treatment schedule of those patients.

Citation Format: Meissner T, Amallraja A, Mark A, Andrews A, Connolly C, Young B, De P, Williams C, Leyland-Jones B. The value of RNA-Seq for the detection of clinically actionable targets in breast cancer - A small cohort analysis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-22.