Acquired Cross-Resistance in Small Cell Lung Cancer due to Extrachromosomal DNA Amplification of MYC Paralogs

Small cell lung cancer (SCLC) presents as a highly chemosensitive malignancy but acquires cross-resistance after relapse. This transformation is nearly inevitable in patients but has been difficult to capture in laboratory models. Here, we present a preclinical system that recapitulates acquired cross-resistance, developed from 51 patient-derived xenograft (PDX) models. Each model was tested in vivo against three clinical regimens: cisplatin plus etoposide, olaparib plus temozolomide, and topotecan. These drug-response profiles captured hallmark clinical features of SCLC, such as the emergence of treatment-refractory disease after early relapse. For one patient, serial PDX models revealed that cross-resistance was acquired through MYC amplification on extrachromosomal DNA (ecDNA). Genomic and transcriptional profiles of the full PDX panel revealed that MYC paralog amplifications on ecDNAs were recurrent in relapsed cross-resistant SCLC, and this was corroborated in tumor biopsies from relapsed patients. We conclude that ecDNAs with MYC paralogs are recurrent drivers of cross-resistance in SCLC.

SIGNIFICANCE

SCLC is initially chemosensitive, but acquired cross-resistance renders this disease refractory to further treatment and ultimately fatal. The genomic drivers of this transformation are unknown. We use a population of PDX models to discover that amplifications of MYC paralogs on ecDNA are recurrent drivers of acquired cross-resistance in SCLC. This article is featured in Selected Articles from This Issue, p. 695.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

A TRIM21-based bioPROTAC highlights the therapeutic benefit of HuR degradation

Human antigen R (HuR) is a ubiquitously expressed RNA-binding protein, which functions as an RNA regulator. Overexpression of HuR correlates with high grade tumours and poor patient prognosis, implicating it as an attractive therapeutic target. However, an effective small molecule antagonist to HuR for clinical use remains elusive. Here, a single domain antibody (VHH) that binds HuR with low nanomolar affinity was identified and shown to inhibit HuR binding to RNA. This VHH was used to engineer a TRIM21-based biological PROTAC (bioPROTAC) that could degrade endogenous HuR. Significantly, HuR degradation reverses the tumour-promoting properties of cancer cells in vivo by altering the HuR-regulated proteome, highlighting the benefit of HuR degradation and paving the way for the development of HuR-degrading therapeutics. These observations have broader implications for degrading intractable therapeutic targets, with bioPROTACs presenting a unique opportunity to explore targeted-protein degradation through a modular approach.

A novel approach using electroacupuncture for erectile dysfunction after radical prostatectomy: A case report

INTRODUCTION

Research shows that electrical stimulation to damaged peripheral nerves has promising effects on nerve regeneration and recovery of function.

DESCRIPTION

A 71 yr. old male, who was 12 months post left intrafacial and right incremental nerve sparing robotic radical prostatectomy received 6 sessions of sacral electroacupuncture/acupuncture at weekly intervals, commencing 12 months post operatively.

METHODS

CARE guidelines informed the case study report. Positive changes in erectile function after electroacupuncture was recorded using validated scores (IIEF-5 and EHS). Qualitative information was collected via a feedback box.

DISCUSSION

Given that current treatments for post radical prostatectomy erectile dysfunction are invasive and largely unsuccessful, further investigation into electroacupuncture for this population should be pursued.

Acquired Cross-resistance in Small Cell Lung Cancer due to Extrachromosomal DNA Amplification of MYC paralogs

Small cell lung cancer (SCLC) presents as a highly chemosensitive malignancy but acquires cross-resistance after relapse. This transformation is nearly inevitable in patients but has been difficult to capture in laboratory models. Here we present a pre-clinical system that recapitulates acquired cross-resistance in SCLC, developed from 51 patient-derived xenografts (PDXs). Each model was tested for in vivo sensitivity to three clinical regimens: cisplatin plus etoposide, olaparib plus temozolomide, and topotecan. These functional profiles captured hallmark clinical features, such as the emergence of treatment-refractory disease after early relapse. Serially derived PDX models from the same patient revealed that cross-resistance was acquired through a MYC amplification on extrachromosomal DNA (ecDNA). Genomic and transcriptional profiles of the full PDX panel revealed that this was not unique to one patient, as MYC paralog amplifications on ecDNAs were recurrent among cross-resistant models derived from patients after relapse. We conclude that ecDNAs with MYC paralogs are recurrent drivers of cross-resistance in SCLC.

SIGNIFICANCE

SCLC is initially chemosensitive, but acquired cross-resistance renders this disease refractory to further treatment and ultimately fatal. The genomic drivers of this transformation are unknown. We use a population of PDX models to discover that amplifications of MYC paralogs on ecDNA are recurrent drivers of acquired cross-resistance in SCLC.

A116 OPTIMIZING CROHN’S DISEASE ENDOSCOPIC SCORING OPERATING CHARACTERISTICS TO ASSIST WITH THE ADVENT OF ARTIFICIAL INTELLIGENCE

Background

To date, no studies have used Artificial Intelligence (AI) to produce standard endoscopic scores for Crohn’s Disease (CD). These scores are essential to clinical practice and have a major cost in clinical trials.

Purpose

We aimed to re-examine the components of the Simple Endoscopic Score for Crohn’s Disease (SES-CD) and Modified Multiplier (MM-SES-CD) to see if scoring of individual colonic segments could be combined while maintaining predictive value accuracy, thus simplifying scoring for AI.

Method

Data from 279 participants in the UNITI and EXTEND trials as well as an infliximab biosimilar trial (NCT02096861) were used in this retrospective study. The primary outcome was endoscopic remission (ER-1) of the colon, defined as absence of ulcers. Secondary outcomes included alternative definitions of colonic endoscopic remission including SES-CD score of 0 (ER-2), SES-CD <3 (ER-3), and SES-CD reduction by 50% or greater from baseline (colonic endoscopic response).

Result(s)

The mean baseline SES-CD score was 13.7 (SD 7.7) and the mean MM-SES-CD score was 22.8 (SD 12.4). Among all possible colonic segment combinations, the combination of Right + Rectum + worst of Left or Transverse performed best for prediction of one-year ER-1, with fair accuracy (AUC 0.71, 95% CI 0.65-0.78, p < 0.0001). Accuracy of prediction of one-year ER-2 was poor (AUC 0.68, 95% CI 0.62-0.75, p < 0.0001), ER-3 was fair (AUC 0.71, 95% CI 0.65-0.77, p < 0.0001), and prediction of endoscopic response was poor (AUC 0.64, 95% CI 0.56-0.72, p > 0.01). These results were very similar to conventional scoring (without combining any “worst of” segments) with all of the colonic MM-SES-CD scores, with AUCs of 0.70, 0.69, 0.71, and 0.61 for the respective outcomes. Assessing only for the presence of ulcers was as accurate as the full assessment and exclusion of scoring stenosis had minimal impact on scores.

Image

Conclusion(s)

By combining assessment of colonic segments accuracy was maintained compared with currently used endoscopic scoring. Assessing for features other than ulceration had no significant impact on overall scores. By combining colonic segments and limiting assessment to ulceration, it may be simpler to develop AI algorithms reliably scoring endoscopic severity of CD for clinical practice and trials.

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Disclosure of Interest

None Declared

Combined PD-1, BRAF and MEK inhibition in BRAFV600E colorectal cancer: a phase 2 trial

While BRAF inhibitor combinations with EGFR and/or MEK inhibitors have improved clinical efficacy in BRAFV600E colorectal cancer (CRC), response rates remain low and lack durability. Preclinical data suggest that BRAF/MAPK pathway inhibition may augment the tumor immune response. We performed a proof-of-concept single-arm phase 2 clinical trial of combined PD-1, BRAF and MEK inhibition with sparatlizumab (PDR001), dabrafenib and trametinib in 37 patients with BRAFV600E CRC. The primary end point was overall response rate, and the secondary end points were progression-free survival, disease control rate, duration of response and overall survival. The study met its primary end point with a confirmed response rate (24.3% in all patients; 25% in microsatellite stable patients) and durability that were favorable relative to historical controls of BRAF-targeted combinations alone. Single-cell RNA sequencing of 23 paired pretreatment and day 15 on-treatment tumor biopsies revealed greater induction of tumor cell-intrinsic immune programs and more complete MAPK inhibition in patients with better clinical outcome. Immune program induction in matched patient-derived organoids correlated with the degree of MAPK inhibition. These data suggest a potential tumor cell-intrinsic mechanism of cooperativity between MAPK inhibition and immune response, warranting further clinical evaluation of optimized targeted and immune combinations in CRC. ClinicalTrials.gov registration: NCT03668431.

1304 LAXATIVES PRESCRIPTION MONITORING FOR AN OVERLOOKED PROBLEM

Introduction

Constipation is a common diagnosis among hospitalized patients. It results in considerable morbidity in elderly patients, healthcare utilization and economic burden. Laxatives are commonly prescribed but poorly monitored due to benign side effect perception.

Aim

We undertook a review of the quality of laxative prescribing and subsequent monitoring amongst an inpatient cohort. We propose new standards:

- Medication review at least once weekly;

- Documented rationale for choice of medication

- Specified timeframe review and outcome documentation

We reviewed current hospital trust policy of laxative prescribing and produced a new constipation management guideline in response to early audit data.

Method

Data collected across medical wards in Trafford General Hospital, Manchester. Data was collected on types of laxatives, reason for prescription, date of review, length of course, compliance and effect of laxatives. Two rounds of audit were performed 6 months apart, with an interim intervention of staff education and local introduction of a new constipation management guideline. The guideline consisted of decision algorithm and suggested treatment.

Results

47 individual prescriptions were audited in round 1 and 72 prescriptions in round 2, this represented 23 and 32 patients respectively. Review of medications within first week of prescription improved from 17% to 83.7% across the two cycles. Documentation of constipation diagnosis improved from 52.2% to 97.2%. There were large percentage improvements in documentation of specified treatment outcomes across all audited fields, despite overall poorer medication compliance among patients in round 2 (56.9% versus 66% in round 1). The average length of laxative use decreased from 18.6 days to 15.3 with overall percentage of patient with constipation resolved increased from 65% in round 1 to 73% in Round 2

Conclusion

Staff education and implementation of treatment guidelines made a substantial improvement to the medical management of constipation in hospitalized patients.

A systematic review of interventions in the early course of bipolar disorder I or II: a report of the International Society for Bipolar Disorders Taskforce on early intervention

BACKGROUND

Given the likelihood of progressive illness in bipolar disorder (BD), it is important to understand the benefits and risks of interventions administered early in illness course. We conducted a systematic review of the effectiveness of interventions in the early course of BD I or II.

METHODS

We completed a systematic search on MEDLINE, PsycINFO, EMBASE, the Cochrane Central Register of Controlled Trials, CINAHL and Google Scholar from 1/1/1979 till 14/9/2022. We included controlled trials examining intervention effects on symptomatic, course, functional and tolerability outcomes of patients in the 'early course' of BD I or II. We classified patients to be in early course if they (a) were seeking help for the first time for a manic episode, (b) had a lifetime history of up to 3 manic episodes, or (c) had up to 6 lifetime mood episodes. Evidence quality was assessed using the GRADE approach.

RESULTS

From 4135 unique publications we included 25 reports representing 2212 participants in 16 randomized studies, and 17,714 participants from nine non-randomized studies. Available evidence suggested that in early illness course, lithium use was associated with lower recurrence risk compared with other mood stabilizers. Mood stabilizers were also associated with better global functioning, compared with the use of antipsychotics in the medium term. While summative findings regarding psychological therapies were limited by heterogeneity, family-focused and cognitive-behavioral interventions were associated with reduced recurrence risk or improved symptomatic outcomes. There was some evidence that the same pharmacological interventions were more efficacious in preventing recurrences when utilized in earlier rather than later illness course.

CONCLUSIONS AND RECOMMENDATIONS

While there are promising initial findings, there is a need for more adequately powered trials to examine the efficacy and tolerability of interventions in youth and adults in early illness course. Specifically, there is a compelling need to compare the relative benefits of lithium with other pharmacological agents in preventing recurrences. In addition to symptomatic outcomes, there should be a greater focus on functional impact and tolerability. Effective pharmacological and psychological interventions should be offered to those in early course of BD, balancing potential risks using shared decision-making approaches.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

KRASG12C-independent feedback activation of wild-type RAS constrains KRASG12C inhibitor efficacy

Although KRAS has long been considered undruggable, direct KRASG12C inhibitors have shown promising initial clinical efficacy. However, the majority of patients still fail to respond. Adaptive feedback reactivation of RAS-mitogen-activated protein kinase (MAPK) signaling has been proposed by our group and others as a key mediator of resistance, but the exact mechanism driving reactivation and the therapeutic implications are unclear. We find that upstream feedback activation of wild-type RAS, as opposed to a shift in KRASG12C to its active guanosine triphosphate (GTP)-bound state, is sufficient to drive RAS-MAPK reactivation in a KRASG12C-independent manner. Moreover, multiple receptor tyrosine kinases (RTKs) can drive feedback reactivation, potentially necessitating targeting of convergent signaling nodes for more universal efficacy. Even in colorectal cancer, where feedback is thought to be primarily epidermal growth factor receptor (EGFR)-mediated, alternative RTKs drive pathway reactivation and limit efficacy, but convergent upstream or downstream signal blockade can enhance activity. Overall, these data provide important mechanistic insight to guide therapeutic strategies targeting KRAS.

Abstract LB003: Combined BRAF, MEK, and PD-1 inhibition in BRAFV600E colorectal cancer patients: Correlative studies from a phase 2 trial

Background: Although BRAF inhibitors combined with EGFR and/or MEK inhibitors have improved efficacy in BRAFV600E colorectal cancer (CRC), response rates remain low and clinical benefit is not durable. Preclinical studies suggest that BRAF-targeted therapy in combination with immune checkpoint blockade could enhance anti-tumor activity. We have previously reported on the efficacy from an ongoing phase 2 clinical trial of anti-PD-1 antibody spartalizumab in combination with BRAF inhibitor dabrafenib and MEK inhibitor trametinib in BRAFV600E CRC patients. Of 26 patients, overall response rate (ORR) was 38% (10/26) and compares favorably to the historical controls in BRAFV600E CRC, yet the mechanisms of patient response in this trial need further investigation.

Methods: Single-cell RNA-seq (scRNA-seq) was performed on 23 paired baseline and day 15 tumor biopsies. Patient-derived organoids (PDOs) were generated from baseline tumor biopsies.

Results: scRNA-seq of paired biopsies revealed increased CD8+ T cell infiltration after treatment in patients with better clinical outcome (PFS &gt; 6 months, n=11). From the on- versus pre-treatment differentially expression analysis and gene set enrichment analysis in the tumor epithelial compartment, we observed greater induction and enrichment of immune gene signatures such as antigen processing and presentation, type I and II interferon response, chemokine activity, as well as superior MAPK pathway inhibition with therapy in patients with PFS &gt; 6 months. In comparison, patients with PFS &lt; 6 months (n=12) showed less immune gene upregulation and MAPK pathway inhibition in tumor cells. PDOs treated with dabrafenib and trametinib exhibited gene expression changes that mirrored the changes observed in scRNA-seq of tumor cells in the same patients from which they were derived. BRAF/ERKi treatment in PDOs produced greater MAPK pathway inhibition and immune genes induction than BRAF/MEKi.

Conclusion: Correlative studies of combined anti-PD-1 and BRAF/MEK inhibition suggest that the tumor-intrinsic immune response induced by MAPK pathway inhibition might underlie cooperativity between BRAF-targeted therapy and immune checkpoint blockade. A greater degree of immune gene induction in tumor cells could be enhanced by superior MAPK pathway inhibition, which provides rationale for further clinical studies.

Citation Format: Jun Tian, Jonathan H. Chen, Sherry X. Chao, Karin Pelka, Vjola Jorgji, Islam Baiev, William B. Bradford, Edmond Wong, Princy Sindurakar, Tomonori Oka, Shadmehr Demehri, Nir Hacohen, Ryan B. Corcoran. Combined BRAF, MEK, and PD-1 inhibition in BRAFV600E colorectal cancer patients: Correlative studies from a phase 2 trial [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 LB003.

Translesion DNA synthesis mediates acquired resistance to olaparib plus temozolomide in small cell lung cancer

In small cell lung cancer (SCLC), acquired resistance to DNA-damaging therapy is challenging to study because rebiopsy is rarely performed. We used patient-derived xenograft models, established before therapy and after progression, to dissect acquired resistance to olaparib plus temozolomide (OT), a promising experimental therapy for relapsed SCLC. These pairs of serial models reveal alterations in both cell cycle kinetics and DNA replication and demonstrate both inter- and intratumoral heterogeneity in mechanisms of resistance. In one model pair, up-regulation of translesion DNA synthesis (TLS) enabled tolerance of OT-induced damage during DNA replication. TLS inhibitors restored sensitivity to OT both in vitro and in vivo, and similar synergistic effects were seen in additional SCLC cell lines. This represents the first described mechanism of acquired resistance to DNA damage in a patient with SCLC and highlights the potential of the serial model approach to investigate and overcome resistance to therapy in SCLC.

Cost-effectiveness of Screening for Paroxysmal Atrial Fibrillation in Patients undergoing Echocardiography

OBJECTIVE

To compare the cost-effectiveness of unselected electrocardiographic (ECG) screening for atrial fibrillation (AF), and selective screening based on an abnormal echocardiogram.

METHODS

Two strategies of portable ECG screening for AF were compared in the base case of a hypothetical asymptomatic 65-year-old man (CHA₂ DS₂ -VASC=3 based on hypertension and diabetes mellitus) with previous echocardiography but without a cause for AF (eg. mitral valve disease, LV dysfunction). With age-based screening (AgeScreen, 3% AF detection rate) all patients underwent ECG. With imaging-guided screening (ImagingScreen; 5% detection rate), only patients with left atrial volume (LA) ≥34ml/m² and LA reservoir strain <34% or LV global longitudinal strain (GLS)>-18% underwent ECG screening. A Markov model was informed by published transition probabilities, costs and quality-adjusted life years (QALY). Costs, effects and incremental cost-effectiveness ratio (ICER) were assessed for each screening strategy over a 20 year period. The willingness-to-pay threshold was $53,000/QALY.

RESULTS

ImagingScreen dominated AgeScreen, with a lower cost ($54,823 vs $57,842) and better outcome (11.56 vs 11.52 QALY over 20 years). Monte Carlo simulation demonstrated that 61% of observations were more efficacious with ImagingScreen, with cost below willingness-to-pay. The main cost determinants were annual costs of stroke or heart failure and AF detection rates. ImagingScreen was more cost-effective for AF detection rates up to 14%, and more cost-effective across a range of annual stroke ($24,000-$102,000) and heart failure ($4,000-$12,000) costs.

CONCLUSION

In patients with a previous echocardiogram, AF screening of those with baseline clinical and imaging risk parameters is more cost-effective than age-based screening. This article is protected by copyright. All rights reserved.

Method To Visualize the Intratumor Distribution and Impact of Gemcitabine in Pancreatic Ductal Adenocarcinoma by Multimodal Imaging

Gemcitabine (dFdC) is a common treatment for pancreatic cancer; however, it is thought that treatment may fail because tumor stroma prevents drug distribution to tumor cells. Gemcitabine is a pro-drug with active metabolites generated intracellularly; therefore, visualizing the distribution of parent drug as well as its metabolites is important. A multimodal imaging approach was developed using spatially coregistered mass spectrometry imaging (MSI), imaging mass cytometry (IMC), multiplex immunofluorescence microscopy (mIF), and hematoxylin and eosin (H&E) staining to assess the local distribution and metabolism of gemcitabine in tumors from a genetically engineered mouse model of pancreatic cancer (KPC) allowing for comparisons between effects in the tumor tissue and its microenvironment. Mass spectrometry imaging (MSI) enabled the visualization of the distribution of gemcitabine (100 mg/kg), its phosphorylated metabolites dFdCMP, dFdCDP and dFdCTP, and the inactive metabolite dFdU. Distribution was compared to small-molecule ATR inhibitor AZD6738 (25 mg/kg), which was codosed. Gemcitabine metabolites showed heterogeneous distribution within the tumor, which was different from the parent compound. The highest abundance of dFdCMP, dFdCDP, and dFdCTP correlated with distribution of endogenous AMP, ADP, and ATP in viable tumor cell regions, showing that gemcitabine active metabolites are reaching the tumor cell compartment, while AZD6738 was located to nonviable tumor regions. The method revealed that the generation of active, phosphorylated dFdC metabolites as well as treatment-induced DNA damage primarily correlated with sites of high proliferation in KPC PDAC tumor tissue, rather than sites of high parent drug abundance.

Multi-modal molecular imaging maps the correlation between tumor microenvironments and nanomedicine distribution

Gaining insight into the heterogeneity of nanoparticle drug distribution within tumors would improve both design and clinical translation of nanomedicines. There is little data showing the spatio-temporal behavior of nanomedicines in tissues as current methods are not able to provide a comprehensive view of the nanomedicine distribution, released drug or its effects in the context of a complex tissue microenvironment. Methods: A new experimental approach which integrates the molecular imaging and bioanalytical technologies MSI and IMC was developed to determine the biodistribution of total drug and drug metabolite delivered via PLA-PEG nanoparticles and to overlay this with imaging of the nanomedicine in the context of detailed tumor microenvironment markers. This was used to assess the nanomedicine AZD2811 in animals bearing three different pre-clinical PDX tumors. Results: This new approach delivered new insights into the nanoparticle/drug biodistribution. Mass spectrometry imaging was able to differentiate the tumor distribution of co-dosed deuterated non-nanoparticle-formulated free drug alongside the nanoparticle-formulated drug by directly visualizing both delivery approaches within the same animal or tissue. While the IV delivered free drug was uniformly distributed, the nanomedicine delivered drug was heterogeneous. By staining for multiple biomarkers of the tumor microenvironment on the same tumor sections using imaging mass cytometry, co-registering and integrating data from both imaging modalities it was possible to determine the features in regions with highest nanomedicine distribution. Nanomedicine delivered drug was associated with regions higher in macrophages, as well as more stromal regions of the tumor. Such a comparison of complementary molecular data allows delineation of drug abundance in individual cell types and in stroma. Conclusions: This multi-modal imaging solution offers researchers a better understanding of drug and nanocarrier distribution in complex tissues and enables data-driven drug carrier design.

Holistic Characterization of a Salmonella Typhimurium Infection Model Using Integrated Molecular Imaging

A more complete and holistic view on host-microbe interactions is needed to understand the physiological and cellular barriers that affect the efficacy of drug treatments and allow the discovery and development of new therapeutics. Here, we developed a multimodal imaging approach combining histopathology with mass spectrometry imaging (MSI) and same section imaging mass cytometry (IMC) to study the effects of Salmonella Typhimurium infection in the liver of a mouse model using the S. Typhimurium strains SL3261 and SL1344. This approach enables correlation of tissue morphology and specific cell phenotypes with molecular images of tissue metabolism. IMC revealed a marked increase in immune cell markers and localization in immune aggregates in infected tissues. A correlative computational method (network analysis) was deployed to find metabolic features associated with infection and revealed metabolic clusters of acetyl carnitines, as well as phosphatidylcholine and phosphatidylethanolamine plasmalogen species, which could be associated with pro-inflammatory immune cell types. By developing an IMC marker for the detection of Salmonella LPS, we were further able to identify and characterize those cell types which contained S. Typhimurium.

Influence of the first wave of COVID-19 on asthma inhaler prescriptions

In the beginning of the COVID-19 pandemic, there were major concerns regarding the huge demand for asthma inhalers. Using the primary-care medical records for 614,700 asthma patients between January and June 2020, we found that there was a substantial increase in inhalers solely in March 2020. Patients significantly associated with receiving higher inhaled corticosteroid prescriptions were younger, of higher socioeconomic status, and had milder asthma.

Retinal microvascular function predicts chronic kidney disease in patients with cardiovascular risk factors

BACKGROUND AND AIMS

Endothelial dysfunction is a precursor to atherosclerosis and is implicated in the coexistence between cardiovascular disease (CVD) and chronic kidney disease (CKD). We examined whether retinal microvascular dysfunction is present in subjects with renal impairment and predictive of long-term CKD progression in patients with CVD.

METHODS

In a single centre prospective observational study, 253 subjects with coronary artery disease and CVD risk factors underwent dynamic retinal vessel analysis. Retinal microvascular dysfunction was quantified by measuring retinal arteriolar and venular dilatation in response to flicker light stimulation. Serial renal function assessment was performed over a median period of 9.3 years using estimated GFR (eGFR).

RESULTS

Flicker light-induced retinal arteriolar dilatation (FI-RAD) was attenuated in patients with baseline eGFR <90 mL/min/1.73 m², compared to those with normal renal function (eGFR ≥90 mL/min/1.73 m²) (1.0 [0.4-2.1]% vs. 2.0 [0.8-3.6]%; p < 0.01). In patients with normal renal function, subjects with the lowest FI-RAD responses exhibited the greatest annual decline in eGFR. In uni- and multivariable analysis, among subjects with normal renal function, a 1% decrease in FI-RAD was associated with an accelerated decline in eGFR of 0.10 (0.01, 0.15; p = 0.03) and 0.07 mL/min/1.73 m² per year (0.00, 0.14; p = 0.06), respectively. FI-RAD was not predictive of CKD progression in subjects with baseline eGFR <90 mL/min/1.73 m².

CONCLUSIONS

Retinal arteriolar endothelial dysfunction is present in patients with CVD who have early-stage CKD, and serves as an indicator of long-term CKD progression in those with normal renal function.

Prevalence and Disparities in Folate and Vitamin B12 Deficiency Among Preschool Children in Guatemala

BACKGROUND AND OBJECTIVE

Folate and vitamin B12 deficiencies can impair proper growth and brain development in children. Data on the folate and vitamin B12 status of children aged 6-59 months in Guatemala are scarce. Identification of factors associated with higher prevalence of these micronutrient deficiencies within the population is needed for national and regional policymakers.

OBJECTIVE

To describe national and regional post-fortification folate and vitamin B12 status of children aged 6-59 months in Guatemala.

METHODS

A multistage, cluster probability study was carried out with national and regional representation of children aged 6-59 months. Demographic and health information was collected for 1246 preschool children, but blood samples for red blood cell (RBC) folate and vitamin B12 were collected and analyzed for 1,245 and 1143 preschool children, respectively. We used the following deficiency criteria as cutoff points for the analyses: < 305 nmol/L for RBC folate, < 148 pmol/L for vitamin B12 deficiency, and 148-221 pmol/L for marginal vitamin B12 deficiency. Prevalence of RBC folate deficiency and vitamin B12 deficiency and marginal deficiency were estimated. Prevalence risk ratios of RBC folate and vitamin B12 deficiency were estimated comparing subpopulations of interest.

RESULTS

The national prevalence estimates of RBC folate deficiency among children was 33.5% [95% CI 29.1, 38.3]. The prevalence of RBC folate deficiency showed wide variation by age (20.3-46.6%) and was significantly higher among children 6-11 months and 12-23 months (46.6 and 37.0%, respectively), compared to older children aged 48-59 months (20.3%). RBC folate deficiency also varied widely by household wealth index (22.6-42.0%) and geographic region (27.2-46.7%) though the differences were not statistically significant. The national geometric mean for RBC folate concentrations was 354.2 nmol/L. The national prevalences of vitamin B12 deficiency and marginal deficiency among children were 22.5% [95% CI 18.2, 27.5] and 27.5% [95% CI 23.7, 31.7], respectively. The prevalence of vitamin B12 deficiency was significantly higher among indigenous children than among non-indigenous children (34.5% vs. 13.1%, aPRR 2.1 95% CI 1.4, 3.0). The prevalence of vitamin B12 deficiency also significantly varied between the highest and lowest household wealth index (34.3 and 6.0%, respectively). The national geometric mean for vitamin B12 concentrations was 235.1 pmol/L. The geometric means of folate and B12 concentrations were significantly lower among children who were younger, had a lower household wealth index, and were indigenous (for vitamin B12 only). Folate and vitamin B12 concentrations showed wide variation by region (not statistically significant), and the Petén and Norte regions showed the lowest RBC folate and vitamin B12 concentrations, respectively.

CONCLUSIONS

In this study, a third of all children had RBC folate deficiency and half were vitamin B12 deficient. Folate deficiency was more common in younger children and vitamin B12 deficiency was more common in indigenous children and those from the poorest families. These findings suggest gaps in the coverage of fortification and the need for additional implementation strategies to address these gaps in coverage to help safeguard the health of Guatemalan children.

Evaluation of serological lateral flow assays for severe acute respiratory syndrome coronavirus-2

BACKGROUND

COVID-19 has resulted in significant morbidity and mortality worldwide. Lateral flow assays can detect anti-Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) antibodies to monitor transmission. However, standardized evaluation of their accuracy and tools to aid in interpreting results are needed.

METHODS

We evaluated 20 IgG and IgM assays selected from available tests in April 2020. We evaluated the assays' performance using 56 pre-pandemic negative and 56 SARS-CoV-2-positive plasma samples, collected 10-40 days after symptom onset, confirmed by a molecular test and analyzed by an ultra-sensitive immunoassay. Finally, we developed a user-friendly web app to extrapolate the positive predictive values based on their accuracy and local prevalence.

RESULTS

Combined IgG + IgM sensitivities ranged from 33.9 to 94.6%, while combined specificities ranged from 92.6 to 100%. The highest sensitivities were detected in Lumiquick for IgG (98.2%), BioHit for both IgM (96.4%), and combined IgG + IgM sensitivity (94.6%). Furthermore, 11 LFAs and 8 LFAs showed perfect specificity for IgG and IgM, respectively, with 15 LFAs showing perfect combined IgG + IgM specificity. Lumiquick had the lowest estimated limit-of-detection (LOD) (0.1 μg/mL), followed by a similar LOD of 1.5 μg/mL for CareHealth, Cellex, KHB, and Vivachek.

CONCLUSION

We provide a public resource of the accuracy of select lateral flow assays with potential for home testing. The cost-effectiveness, scalable manufacturing process, and suitability for self-testing makes LFAs an attractive option for monitoring disease prevalence and assessing vaccine responsiveness. Our web tool provides an easy-to-use interface to demonstrate the impact of prevalence and test accuracy on the positive predictive values.

POS0670 ROUTINE ASSESSMENT OF PATIENT INDEX DATA 3 (RAPID3) IN PATIENTS WITH RHEUMATOID ARTHRITIS TREATED WITH LONG-TERM UPADACITINIB THERAPY

Background:

Routine Assessment of Patient Index Data 3 (RAPID3) is a pooled index of 3 patient-reported measures: patient global assessment, pain, and physical function. RAPID3 was shown to correlate with other composite measures of disease activity1 and is recommended by the American College of Rheumatology for use in clinical practice.2

Objectives:

To evaluate the impact of upadacitinib (UPA) versus comparators on RAPID3 over 60 weeks, as well as the correlation of RAPID3 scores with other disease measures in the UPA phase 3 SELECT clinical program.

Methods:

This post hoc analysis included placebo-controlled (SELECT-NEXT, -BEYOND, and -COMPARE) and active comparator-controlled (SELECT-EARLY, -MONOTHERAPY, and -COMPARE) trials. Patients received UPA as monotherapy or in combination with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Mean change from baseline in RAPID3 and the proportion of patients reporting RAPID3 remission (≤3), low (LDA, >3 to ≤6), moderate (MDA, >6 to ≤12), and high disease activity (HDA, >12) were assessed. Correlations between absolute scores for RAPID3 and Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), and 28-joint Disease Activity Score with C-reactive protein (DAS28[CRP]) were assessed using Spearman correlation coefficients. All data are as observed.

Results:

A total of 661, 498, 648, 1629, and 945 patients were included from SELECT-NEXT, -BEYOND, -MONOTHERAPY, -COMPARE, and -EARLY. At baseline, the majority of patients across all studies were in RAPID3 HDA (mean baseline RAPID3 [across all studies], 17.2–19.2) (Table 1 and Figure 1). Improvements from baseline in RAPID3 were observed with UPA 15 mg and 30 mg through Week 60, with numerically greater improvements observed with UPA compared with active comparators (Table 1). Across studies, mean improvements in RAPID3 exceeded the minimal clinically important difference (MCID) with UPA and adalimumab (ADA) treatment (MCID=3.83). By Week 60, approximately one-half of UPA-treated patients were in RAPID3 remission or LDA, with only 10–25% remaining in HDA, except for the more refractory population in SELECT-BEYOND, in which ~38% of patients remained in HDA (Figure 1). RAPID3 scores moderately to strongly correlated with CDAI (ρ=0.69–0.83), SDAI (ρ=0.69–0.82), and DAS28(CRP) (ρ=0.58–0.77), across all studies, at Week 60 (all p<0.001).

Conclusion:

UPA, as monotherapy or in combination with csDMARDs, was associated with improvements in patient-reported disease activity, pain, and physical function, as assessed by RAPID3 over 60 weeks in the phase 3 SELECT clinical program. RAPID3 continues to be an important tool in clinical practice to assess disease activity, as it was shown to correlate to other disease activity measures and allows for rapid scoring.

References:

[1]Pincus T, et al. Arthritis Care Res (Hoboken) 2010;62:181–9.

[2]England BR, et al. Arthritis Care Res (Hoboken) 2019;71:1540–55.

[3]Ward MM, et al. J Rheumatol 2019;46:27–30.

Table 1.

Change from BL in RAPID3 at Week 60 (as observed)

Phase 3 studyGroupnaMean (SD) BL scoreMean (SD) change from BLbSELECT-EARLYc(MTX-naïve)MTX23618.5 (5.6)−9.6 (7.5)UPA 15 mg QD26918.9 (5.6)−12.0 (7.6)UPA 30 mg QD25318.2 (5.6)−13.4 (7.2)SELECT-NEXT(csDMARD-IR)UPA 15 mg QD17217.7 (5.1)−11.1 (7.3)UPA 30 mg QD17217.6 (5.3)−10.4 (6.8)SELECT-MONOTHERAPY(MTX-IR)UPA 15 mg QD17217.4 (5.8)−9.6 (7.4)UPA 30 mg QD18017.2 (5.9)−10.6 (7.2)SELECT-COMPAREc(MTX-IR)UPA 15 mg QD55218.5 (5.5)−10.2 (7.1)ADA 40 mg EOW26418.7 (5.4)−8.8 (6.7)SELECT-BEYOND(bDMARD-IR)UPA 15 mg QD13319.2 (5.1)−8.6 (6.8)UPA 30 mg QD11818.5 (5.3)−9.3 (7.3)

b, biologic; BL, baseline; EOW, every other week; IR, inadequate response; MTX, methotrexate; QD, once daily; SD, standard deviation

aNumber of patients with RAPID3 values at both BL and Week 60. bNegative values indicate improvement from BL. cObserved data include patients rescued to UPA and/or ADA; treatment effect may include both the randomized and switch treatments in these patients

Acknowledgements:

AbbVie funded this study; contributed to its design; participated in data collection, analysis, and interpretation of the data; and participated in the writing, review, and approval of the abstract. No honoraria or payments were made for authorship. Medical writing support was provided by Grant Kirkpatrick, MSc, of 2 the Nth (Cheshire, UK), and was funded by AbbVie.

Disclosure of Interests:

Martin Bergman Shareholder of: Johnson & Johnson, Speakers bureau: AbbVie, Celgene, GSK, MSD, Novartis, Pfizer, and Sanofi/Regeneron, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Genentech/Roche, Gilead, Horizon, Janssen, MSD, Novartis, Pfizer, Sandoz, Sanofi/Regeneron, and Scipher, Maya H Buch Consultant of: AbbVie, Eli Lilly, Merck-Serono, Pfizer, Sandoz, and Sanofi, Grant/research support from: Pfizer, Roche, and UCB, Yoshiya Tanaka Speakers bureau: AbbVie, Asahi Kasei, Astellas, Bristol-Myers Squibb, Chugai, Daiichi Sankyo, Eisai, Eli Lilly, GSK, Janssen, Mitsubishi Tanabe, Novartis, Pfizer, Sanofi, Takeda, UCB, and YL Biologics, Grant/research support from: AbbVie, Astellas, Bristol-Myers Squibb, Chugai, Daiichi Sankyo, Eisai, Mitsubishi Tanabe, MSD, Ono, Taisho Toyama, and Takeda, Gustavo Citera Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Genzyme, Pfizer, and Roche, Sami Bahlas: None declared, Ernest Wong Consultant of: AbbVie, Chugai, Eli Lilly, MSD, Novartis, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, Chugai, Novartis, and UCB, Yanna Song Shareholder of: May own stock or options in AbbVie, Employee of: AbbVie, Namita Tundia Shareholder of: May own stock or options in AbbVie, Employee of: AbbVie, Jessica Suboticki Shareholder of: May own stock or options in AbbVie, Employee of: AbbVie, Vibeke Strand Consultant of: AbbVie, Amgen, Arena, AstraZeneca, Bayer, Bristol-Myers Squibb, Boehringer Ingelheim, Celltrion, Eli Lilly, Gilead, Ichnos, Inmedix, Janssen, Kiniksa, MSD, Myriad Genetics, Novartis, Pfizer, Regeneron, Samsung, Sandoz, Sanofi, Scipher, Setpoint, and UCB.

Direct-to-consumer marketing (DTC) of internet-based cognitive behavioral therapy (iCBT) using brief promotional video: Mapping modifiable mechanisms in pre-treatment acceptance

Introduction

Given the suboptimal acceptance of iCBT for depression, finding ways to increase the acceptance and uptake is crucial for its dissemination. Moreover, it remains unknown to what extend the Unified Theory of Acceptance and Use of Technology (UTAUT) could aid the design of DTC in psychological service.

Objectives

To explore whether the regulatory processes theorized in the UTAUT (Performance Expectancy, Effort Expectancy, Social Influence, and Facilitating Condition) could be modified and mediate the change of acceptance of iCBT.

Methods

This randomized controlled trial recruited 219 individuals with at least mild level of depression. Upon completion of pre-assessment, participants were randomly allocated to an intervention (IG) and a control group (CG). The IG received a 7-minute UTAUT-driven promotion video, while the CG received a video of same length on general psychoeducation. Both groups completed a post-assessment.

Results

Repeated measures ANOVA revealed a significant time by group effect on treatment acceptance. The video in IG was perceived to be clearer and more persuasive. Mediation analysis showed that the intervention effect was mediated by increase in perceived performance expectancy of iCBT, and the indirect effect was conditional on dispositional help seeking stigma.

Conclusions

Pre-treatment acceptance of iCBT can be improved by brief DTC promotion video. The finding casts light that performance expectancy was the most modifiable and mediatable regulatory process on iCBT acceptance, although such relation could be attenuated by high help-seeking stigma. In sum, DTC marketing could aid implementation of Internet-based interventions, effort in stigma reduction should continue to encourage uptake of effective treatment.

Disclosure

No significant relationships.

A catalog of associations between rare coding variants and COVID-19 outcomes

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease-19 (COVID-19), a respiratory illness that can result in hospitalization or death. We investigated associations between rare genetic variants and seven COVID-19 outcomes in 543,213 individuals, including 8,248 with COVID-19. After accounting for multiple testing, we did not identify any clear associations with rare variants either exome-wide or when specifically focusing on (i) 14 interferon pathway genes in which rare deleterious variants have been reported in severe COVID-19 patients; (ii) 167 genes located in COVID-19 GWAS risk loci; or (iii) 32 additional genes of immunologic relevance and/or therapeutic potential. Our analyses indicate there are no significant associations with rare protein-coding variants with detectable effect sizes at our current sample sizes. Analyses will be updated as additional data become available, with results publicly browsable at https://rgc-covid19.regeneron.com.

Method to Investigate the Distribution of Water-Soluble Drug-Delivery Systems in Fresh Frozen Tissues Using Imaging Mass Cytometry

Imaging mass cytometry (IMC) offers the opportunity to image metal- and heavy halogen-containing xenobiotics in a highly multiplexed experiment with other immunochemistry-based reagents to distinguish uptake into different tissue structures or cell types. However, in practice, many xenobiotics are not amenable to this analysis, as any compound which is not bound to the tissue matrix will delocalize during aqueous sample-processing steps required for IMC analysis. Here, we present a strategy to perform IMC experiments on a water-soluble polysarcosine-modified dendrimer drug-delivery system (S-Dends). This strategy involves two consecutive imaging acquisitions on the same tissue section using the same instrumental platform, an initial laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MSI) experiment followed by tissue staining and a standard IMC experiment. We demonstrated that settings can be found for the initial ablation step that leave sufficient residual tissue for subsequent antibody staining and visualization. This workflow results in lateral resolution for the S-Dends of 2 μm followed by imaging of metal-tagged antibodies at 1 μm.

High Frequency of Anticoagulation Management Errors Preceding Ischemic Strokes in Atrial Fibrillation

BACKGROUND AND AIMS

Anticoagulants are recommended to prevent cardioembolic stroke in most patients with atrial fibrillation (AF). Management errors with anticoagulation and use of aspirin instead of anticoagulants have been documented worldwide, especially with vitamin K antagonists. We assessed the rate of anticoagulant mismanagement errors in patients admitted with ischemic stroke, and the clinical correlates with stroke outcomes in the era of non-vitamin K oral anticoagulants.

METHODS

We performed a retrospective analysis of patients admitted with ischemic stroke and history of AF to a single-centre tertiary hospital stroke unit in Melbourne, Australia, between January 2016 and June 2019. We assessed management errors as defined using European Heart Rhythm Association criteria with anticoagulation in the two weeks prior to the index stroke.

RESULTS

A total of 306 patients with AF and ischemic stroke were included, of whom 196 (64%) had management errors. Patients with management errors were older (median age 84 versus 81 years [p=0.002]) and more often female (53% verse 38% [p=0.02]). Of those with management errors, 74 (37%) were not prescribed any anticoagulation despite increased stroke risk and absence of contraindications and 40 (20%) had anticoagulation inappropriately ceased. Mortality at 3-months was 32% in those with management errors, compared to 17% in the appropriately anticoagulated group (p=0.005).

CONCLUSIONS

Inappropriate management of anticoagulants is present in the majority of acute ischemic stroke in the 2 weeks preceding the event and is linked to higher mortality. Improved anticoagulation practice has the potential to substantially reduce stroke rates in patients with AF. This article is protected by copyright. All rights reserved.

Worsening respiratory failure in an adult hydrocephalic patient with a ventriculo-pleural shunt

Ventriculo-pleural (VPL) shunt insertion is performed in hydrocephalic patients when alternative sites of cerebrospinal fluid (CSF) diversion are contraindicated. These include patients with peritoneal complications from ventriculo-peritoneal shunts. Despite its utility, VPL shunts are uncommon. Hydrothoraces should be considered as a potential cause of dyspnoea in the setting of a VPL shunt. We present a case of worsening respiratory failure in the setting of a massive CSF hydrothorax in a hydrocephalic patient with a VPL shunt to highlight this potential complication of pleural CSF diversion, and present a potential management strategy in patients with premorbid underlying lung pathology. In this case, the hydrothorax was drained and the shunt was converted to ventriculo-atrial (VA) shunt.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

1202 Validation Of A Novel Wearable Home Sleep Testing Device For Assessment Of Obstructive Sleep Apnea

Introduction

There is a substantial need for an accurate and easy-to-use tool for obstructive sleep apnea (OSA) assessment. Belun Ring Platform (BRP), a novel photoplethysmography (PPG)-based home sleep apnea testing system with a proprietary deep learning algorithm, has been shown to have good sensitivity and specificity in predicting OSA in subjects without significant comorbidities and medications known to affect heart rate (HR). In this study, we further tested its performance in subjects referred for in-lab polysomnography (PSG) assessment of sleep disorders without excluding those with non-arrhythmia comorbidities or the subjects on HR-affecting medications.

Methods

PSG was recorded simultaneously with the Ring in the sleep lab and the studies were manually scored by certified sleep technicians according to the AASM Scoring manual version 2.4. Exclusion criteria include age &lt;18, unstable cardiopulmonary status, recent hospitalization within 30 days, significant arrhythmias, baseline HR &lt;50 or &gt;100, home oxygen use, pacemaker/defibrillator, post-cardiac transplantation or Left ventricular assist device.

Results

A cohort of 78 individuals (26 males and 52 females, age 50.5) were studied with 26 taking HR-affecting medications. Of these, 35 (45%) had AHI &lt; 5; 14 (18%) had AHI 5-15; 15 (19%) had AHI 15-30; 14 (18%) had AHI &gt; 30. The Ring-REI correlated well with the PSG-AHI (r =0.83, P &lt;0.001). The accuracy, sensitivity, specificity in categorizing AHI &gt;15 were 0.808, 0.931, and 0.735 respectively. The positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 0.675, 0.947, 3.509, and 0.094 respectively. The use of HR-affecting medications did not significantly affect the sensitivity and specificity of BRP in predicting OSA (P =0.16 and 0.44 respectively).

Conclusion

BRP is promising as a reasonable tool for OSA assessment and can potentially be incorporated into a broad spectrum of clinical practices for identification of patients with OSA.

Support

This study is supported by a Grant from Belun Technology Company Limited.

Vertical Pathway Inhibition Overcomes Adaptive Feedback Resistance to KRASG12C Inhibition

PURPOSE

Although KRAS represents the most commonly mutated oncogene, it has long been considered an "undruggable" target. Novel covalent inhibitors selective for the KRASG12C mutation offer the unprecedented opportunity to target KRAS directly. However, prior efforts to target the RAS-MAPK pathway have been hampered by adaptive feedback, which drives pathway reactivation and resistance.

EXPERIMENTAL DESIGN

A panel of KRASG12C cell lines were treated with the KRASG12C inhibitors ARS-1620 and AMG 510 to assess effects on signaling and viability. Isoform-specific pulldown of activated GTP-bound RAS was performed to evaluate effects on the activity of specific RAS isoforms over time following treatment. RTK inhibitors, SHP2 inhibitors, and MEK/ERK inhibitors were assessed in combination with KRASG12C inhibitors in vitro and in vivo as potential strategies to overcome resistance and enhance efficacy.

RESULTS

We observed rapid adaptive RAS pathway feedback reactivation following KRASG12C inhibition in the majority of KRASG12C models, driven by RTK-mediated activation of wild-type RAS, which cannot be inhibited by G12C-specific inhibitors. Importantly, multiple RTKs can mediate feedback, with no single RTK appearing critical across all KRASG12C models. However, coinhibition of SHP2, which mediates signaling from multiple RTKs to RAS, abrogated feedback reactivation more universally, and combined KRASG12C/SHP2 inhibition drove sustained RAS pathway suppression and improved efficacy in vitro and in vivo.

CONCLUSIONS

These data identify feedback reactivation of wild-type RAS as a key mechanism of adaptive resistance to KRASG12C inhibitors and highlight the potential importance of vertical inhibition strategies to enhance the clinical efficacy of KRASG12C inhibitors.See related commentary by Yaeger and Solit, p. 1538.

Comment on the European position paper on diagnostic tools in rhinology â€" computational fluid dynamics

We read with interest the excellent paper authored by Rimmer et al. (1) entitled The European Position Paper on Diagnostic Tools in Rhinology. The authors are to be commended for their comprehensive, up-to-date and thorough summary of available tests in the assessment of rhinologic function. The paper describes traditional tools used in nasal airway obstruction (NAO); including subjective patient reported outcome measure questionnaires (PROMs) such as the NOSE scale; tests that are subjective to the clinician, such as clinical examination, nasendoscopy and imaging; and objective tests such peak nasal inspiratory flow (PNIF), rhinomanometry (RM) and acoustic rhinometry (AR). Unfortunately, each of these readily available, traditional tools fail to meet several accepted criteria of an ideal diagnostic test (Table 1), as outlined (2,3). In our opinion, these limitations restrict the capacity of Rhinology to develop as a discipline founded on sound evidence-based science.

Mapping the binding sites of antibodies utilized in programmed cell death ligand-1 predictive immunohistochemical assays for use with immuno-oncology therapies

Programmed cell death ligand-1 (PD-L1) expression levels in patient tumor samples have proven clinical utility across various cancer types. Several independently developed PD-L1 immunohistochemical (IHC) predictive assays are commercially available. Published studies using the VENTANA PD-L1 (SP263) Assay, VENTANA PD-L1 (SP142) Assay, Dako PD-L1 IHC 22C3 pharmDx assay, Dako PD-L1 IHC 28-8 pharmDx assay, and laboratory-developed tests utilizing the E1L3N antibody (Cell Signaling Technology), have demonstrated differing levels of PD-L1 staining between assays, resulting in conjecture as to whether antibody-binding epitopes could be responsible for discordance between assays. Therefore, to understand the performance of different PD-L1 predictive immunohistochemistry assays, we aimed to distinguish the epitopes within the PD-L1 protein responsible for antibody binding. The sites at which antibody clones SP263, SP142, 22C3, 28-8, and E1L3N bind to recombinant PD-L1 were assessed using several methods, including conformational peptide array, surface plasmon resonance, and/or hydrogen/deuterium exchange mass spectrometry. Putative binding sites were confirmed by site-directed mutagenesis of PD-L1, followed by western blotting and immunohistochemical analysis of cell lines expressing mutant constructs. Our results demonstrate that clones SP263 and SP142 bind to an identical epitope in the cytoplasmic domain at the extreme C-terminus of PD-L1, distinct from 22C3 and 28-8. Using mutated PD-L1 constructs, an additional clone, E1L3N, was also found to bind to the cytoplasmic domain of PD-L1. The E1L3N binding epitope overlaps considerably with the SP263/SP142 binding site but is not identical. Clones 22C3 and 28-8 have binding profiles in the extracellular domain of PD-L1, which differ from one another. Despite identifying epitope binding variance among antibodies, evidence indicates that only the SP142 assay generates significantly discordant immunohistochemical staining, which can be resolved by altering the assay protocol. Therefore, inter-assay discordances are more likely attributable to tumor heterogeneity, assay, or platform variables rather than antibody epitope.

Correction: Mapping the binding sites of antibodies utilized in programmed cell death ligand-1 predictive immunohistochemical assays for use with immuno-oncology therapies

An amendment to this paper has been published and can be accessed via a link at the top of the paper.