At the Crossroads! Time to Start Taking Smartwatches Seriously

Patients have demonstrated a growing interest in using wearable devices, particularly smartwatches, to monitor and improve their cardiovascular wellness. Wearable devices are now one of the fastest growing sectors of the technology industry, and big technology companies, such as Apple (Apple Watch), Google (Fitbit), and Samsung (Galaxy), have engineered smartwatch features that are capable of monitoring biometrics, such as heart rhythm, heart rate, blood pressure, and sleep. These devices hold significant potential to impact the relation between cardiologists and their patients, but concerns exist about device trustworthiness to detect pertinent data points and deliver alerts with accuracy. How these devices' features will interplay with cardiologists' workflow has also yet to be defined and requires thoughtful implementation. Furthermore, the success of smartwatches as medical devices is dependent on patients' continuous use. Keeping patients engaged with their devices through leveraging behavioral factors may lead to achieving and optimizing healthcare goals. Socioeconomic disparities and privacy concerns are other barriers in the path forward. Cardiovascular professional societies are uniquely poised to help impact how these devices are eventually accepted and used in everyday practice. In conclusion, engagement and collaboration with big tech companies will help guide how this market grows.

LB0005 ORELABRUTINIB, AN IRREVERSIBLE INHIBITOR OF BRUTON’S TYROSINE KINASE (BTK), FOR THE TREATMENT OF SYSTEMIC LUPUS ERYTHEMATOSUS (SLE): RESULTS OF A RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, PHASE IB/IIA DOSE-FINDING STUDY

Background

Orelabrutinib is an oral, highly-selective, irreversible inhibitor of Bruton’s tyrosine kinase (BTK). Orelabrutinib has been approved for the treatment of B cell malignancies in China. Two distinct lupus animal models showed significant efficacy of orelabrutinib in reducing disease activity, which supported the clinical development of orelabrutinib in Systemic Lupus Erythematosus (SLE).

Objectives

This phase Ib/IIa, randomized, double-blind, placebo-controlled, dose-finding study aimed to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), preliminary efficacy and biomarkers of orelabrutinib in patients with mild to moderate SLE who received standard of care (SoC) therapy.

Methods

Patients diagnosed with SLE by the ACR classification criteria for ≥ 6 months, who had a SLEDAI-2K score ≥5 at screening, and were autoantibody-positive, were randomized 1:1:1:1 to receive oral orelabrutinib at 50mg, 80mg, 100mg or placebo once daily for 12 weeks, respectively.

Results

This study randomized 60 patients with 55 patients who completed 12-week treatment. Age at baseline was 33.7±9.8 years and 96.7% were female. Baseline disease characteristics were generally balanced across treatment groups. Adverse events (AEs) were reported in 80%, 93.3% and 100% of orelabrutinib treated patients at doses of 50mg, 80mg and 100mg QD respectively versus 85.5% in placebo group. AEs were mostly mild or moderate. Treatment-related SAEs were reported in 3 patients treated with orelabrutinib, only 1 of which was grade 3. No deaths were reported. The plasma exposure of orelabrutinib (AUC and Cmax) was proportionally increased with doses. Nearly complete BTK occupancy was achieved at all dose levels, and the occupancy lasted for 24 hours without any decrease compared to that at 4 hour post-dosing. In all evaluable patients, the SLE Response Index (SRI)-4 response rates at week 12 were 50.0%, 61.5% and 64.3% in patients treated with orelabrutinib at 50mg (n=14), 80mg (n=13) and 100mg (n=14) respectively, compared with 35.7% in patients treated with placebo (n=14), which indicated the trend of dose-dependent improvement. Among the subgroup of patients with SLEDAI-2K≥8 at screening, SRI-4 response occurred in 70%, 70% and 66.7% of patients treated with orelabrutinib at 50mg (n=10), 80mg (n=10) and 100mg (n=9), respectively, compared with 30% who received placebo (n=10). Trends of reduced proteinuria, anti-dsDNA and IgG, total B cells and increased complements C4 were also observed following orelabrutinib treatment.

Conclusion

Orelabrutinib was generally safe and well tolerated in patients with SLE. Preliminary results also suggested encouraging efficacy which supports further development of orelabrutinib in larger and longer trials for SLE.

Table 1.

Efficacy results at week 12.

All Evaluable PatientsPlaceboOrelabrutinibOrelabrutinibOrelabrutinib50 mg80 mg100 mgN=5514141314SRI-4 response, n (%)5 (35.7%)7 (50.0%)8 (61.5%)9 (64.3%)Treatment difference vs. PBO (%)14.3%25.8%28.6%SLEDAI-2K≥8, N=391010109SRI-4 response, n (%)3 (30.0%)7 (70.0%)7 (70.0%)6 (66.7%)Treatment difference vs. PBO (%)40.0%40.0%36.7%

Note: All evaluable patients at week 12 efficacy data were included in the efficacy analysis.

Figure 1.

SRI-4 response rates at week 12.

Disclosure of Interests

Ru Li: None declared, Xiaoxia Zhu: None declared, Shengyun Liu: None declared, Xiao Zhang: None declared, Changhao Xie: None declared, Zili Fu: None declared, Anbin Huang: None declared, Lingyun Sun: None declared, Dongzhou Liu: None declared, Jinxia Zhao: None declared, Lin Wu: None declared, Zhoushuai Qin Employee of: InnoCare Pharma Limited., Sichen Li Employee of: InnoCare pharma Limited., Yaorong Liu Employee of: InnoCare pharma Limited., Zhanguo Li: None declared

Temporal variation of imidacloprid concentration and risk in waterways discharging to the Great Barrier Reef and potential causes

The widely used neonicotinoid insecticide imidacloprid has emerged as a significant risk to surface waters and the diverse aquatic and terrestrial fauna these ecosystems support. While herbicides have been the focus of research on pesticides in Australia's Great Barrier Reef catchment area, imidacloprid has been monitored in catchments across the region since 2009. This study assessed the spatial and temporal dynamics of imidacloprid in 14 waterways in Queensland, Australia over seven years in relation to land use and concentration trends. Imidacloprid could be quantified (i.e., concentrations were greater than the limit of reporting) in approximately 54% of all samples, but within individual waterways imidacloprid was quantified in 0 to 99.7% of samples. The percent of each catchment used to grow bananas, sugar cane and urban explained approximately 45% of the variation in imidacloprid concentrations and waterway discharge accounted for another 18%. In six waterways there were significant increases in imidacloprid concentrations and the frequency and magnitude of exceedances of aquatic ecosystem protection guidelines over time. Overall, the risk posed by imidacloprid was low with 74% of samples protecting at least 99% of species but it was estimated that upto 42% of aquatic species would experience harmful chronic effects. Potential explanations of the changes in imidacloprid were examined. Not surprisingly, the only plausible explanation of the increases was increased use of imidacloprid. While field-based measurement of the effects of imidacloprid are limited in the Great Barrier Reef Catchment Area (GBRCA) the risk assessment indicates that biological harm to aquatic organisms is highly likely. Action to reduce imidacloprid concentrations in the GBRCA waterways is urgently required to reverse the current trends and mitigate environmental impacts.

Evaluating the population-level effects of oxycodone restrictions on prescription opioid utilization in Ontario

PURPOSE

To investigate the impact of restrictions on access to long acting oxycodone on prescription opioid use and opioid-related harms.

METHODS

Administrative health data from Ontario, Canada was used to measure differences in opioids dispensed and ED visits for opioid-related overdose, poisoning or substance use following provincial restrictions on access to publicly insured OxyContin (February 29, 2012) and OxyNeo (February 28, 2013). This study focused on the cohort of provincial drug insurance eligible people (people 65+ and select low-income populations) who were dispensed oxycodone prior to the restrictions. Difference-in-differences models with a propensity score matched comparison group of people who were dispensed non-oxycodone opioids were used to estimate the main effects.

RESULTS

In the six months following the delisting of OxyContin, MMEs per person per week for all opioids fell by an average of 7.5% in people dispensed oxycodone relative to the comparison group, and an average of 13.8% in chronic recipients of oxycodone. In the six months following the restrictions on OxyNeo, MMEs per person per week fell by an average of 3.1% in all people dispensed oxycodone, and 25.2% in chronic oxycodone recipients. The decline in oxycodone dispensing amongst chronic oxycodone recipients corresponded with an increase in dispensing of other opioid formulations, particularly hydromorphone and fentanyl. No important differences were observed for ED visits related to opioid poisoning, overdose, or substance use disorder.

CONCLUSIONS

Province-wide restrictions on access to long acting oxycodone had an impact on quantities of all opioids dispensed to chronic recipients of oxycodone, but small impacts on the full population of people dispensed oxycodone; the decline in use was partially offset by increases in use of other publicly-funded opioid formulations. This study suggests that policies limiting access to specific prescription opioids led to overall reductions in publicly-funded prescription opioid use, particularly in chronic oxycodone recipients, without immediate evidence of changes in opioid-related ED visits. This article is protected by copyright. All rights reserved.

Scalable Science Education via Online Cooperative Questioning

A critical goal for science education is to design and implement learning activities that develop a deep conceptual understanding, are engaging for students, and are scalable for large classes or those with few resources. Approaches based on peer learning and online technologies show promise for scalability but often lack a grounding in cognitive learning principles relating to conceptual understanding. Here, we present a novel design for combining these elements in a principled way. The design centers on having students author multiple-choice questions for their peers using the online platform PeerWise, where beneficial forms of cognitive engagement are encouraged via a series of supporting activities. We evaluated an implementation of this design within a cohort of 632 students in an undergraduate biochemistry course. Our results show a robust relationship between the quality of question authoring and relevant learning outcomes, even after controlling for the confounding influence of prior grades. We conclude by discussing practical and theoretical implications.

Antibody Response to SARS-CoV-2 Vaccination in Patients Following Allogeneic Hematopoietic Cell Transplantation

Vaccines against SARS-CoV-2 have been rapidly approved. Although pivotal studies were conducted in healthy volunteers, little information is available on the safety and efficacy of mRNA vaccines in immunocompromised patients, including recipients of allogeneic hematopoietic cell transplantation (allo-HCT). Here we used a novel assay to analyze patient- and transplantation-related factors and their influence on immune responses to SARS-CoV-2 vaccination over an extended period (up to 6 months) in a large and homogenous group of allo-HCT recipients at a single center in Switzerland. We examined longitudinal antibody responses to SARS-CoV-2 vaccination with BNT162b2 (BioNTech/Pfizer) and mRNA-1273 (Moderna) in 110 allo-HCT recipients and 86 healthy controls. Seroprofiling recording IgG, IgA, and IgM reactivity against SARS-CoV-2 antigens (receptor-binding domain, spike glycoprotein subunits S1 and S2, and nucleocapsid protein) was performed before vaccination, before the second dose, and at 1, 3, and 6 months after the second dose. Patients were stratified to 3 groups: 3 to 6 months post-allo-HCT, 6 to 12 months post-allo-HCT, and >12 months post-allo-HCT. Patients in the 3 to 6 months and 6 to 12 months post-allo-HCT groups developed significantly lower antibody titers after vaccination compared with patients in the >12 months post-allo-HCT group and healthy controls (P < .001). Within the cohort of allo-HCT recipients, patients age >65 years (P = .030), those receiving immunosuppression for prevention or treatment of graft-versus-host disease (GVHD) (P = .033), and patients with relapsed disease (P = .014) displayed low humoral immune responses to the vaccine. In contrast, the intensity of the conditioning regimen, underlying disease (myeloid/lymphoid/other), and presence of chronic GVHD had no impact on antibody levels. Antibody titers achieved the highest levels at 1 month after the second dose of the vaccine but waned substantially in all transplantation groups and healthy controls over time. This analysis of long-term vaccine antibody response is of critical importance to allo-HCT recipients and transplant physicians to guide treatment decisions regarding revaccination and social behavior during the SARS-CoV-2 pandemic.

[A challenge for colorectal surgeons: pathogenesis, progression and management of the secondary tumors of the ovary]

A common clinical problem encountered by colorectal surgeons is the secondary tumors of the ovary (STO), particularly in young female patients. Most STO are from the digestive tract, and the known possible metastatic mechanisms include lymphatic, hematogenous, and intraperitoneal spreading. The molecular and histopathological characteristics of STO from different sites are diverse. It is particularly important to correctly identify the origin and feature of STO, which should be clarified by combining medical history, histopathology, immunohistochemistry, molecular biology, imaging and other means. The prognosis of patients with STO is poor in general. Comprehensive therapies based on surgical resection can benefit some patients. There is no specific treatment for STO at present, but not giving up easily on these patients is the right choice that every surgeon should understand.

Calcium-Sensing Receptors Control CYP27B1-Luciferase Expression: Transcriptional and Posttranscriptional Mechanisms

25-hydroxyvitamin D 1α-hydroxylase (encoded by CYP27B1), which catalyzes the synthesis of 1,25-dihydroxyvitamin D₃, is subject to negative or positive modulation by extracellular Ca²⁺ (Ca²⁺_o) depending on the tissue. However, the Ca²⁺ sensors and underlying mechanisms are unidentified. We tested whether calcium-sensing receptors (CaSRs) mediate Ca²⁺_o-dependent control of 1α-hydroxylase using HEK-293 cells stably expressing the CaSR (HEK-CaSR cells). In HEK-CaSR cells, but not control HEK-293 cells, cotransfected with reporter genes for CYP27B1-Photinus pyralis (firefly) luciferase and control Renilla luciferase, an increase in Ca²⁺_o from 0.5mM to 3.0mM induced a 2- to 3-fold increase in firefly luciferase activity as well as mRNA and protein levels. Surprisingly, firefly luciferase was specifically suppressed at Ca²⁺_o ≥ 5.0mM, demonstrating biphasic Ca²⁺_o control. Both phases were mediated by CaSRs as revealed by positive and negative modulators. However, Ca²⁺_o induced simple monotonic increases in firefly luciferase and endogenous CYP27B1 mRNA levels, indicating that the inhibitory effect of high Ca²⁺_o was posttranscriptional. Studies with inhibitors and the CaSR C-terminal mutant T888A identified roles for protein kinase C (PKC), phosphorylation of T888, and extracellular regulated protein kinase (ERK)_1/2 in high Ca²⁺_o-dependent suppression of firefly luciferase. Blockade of both PKC and ERK_1/2 abolished Ca²⁺_o-stimulated firefly luciferase, demonstrating that either PKC or ERK_1/2 is sufficient to stimulate the CYP27B1 promoter. A key CCAAT box (−74 bp to −68 bp), which is regulated downstream of PKC and ERK_1/2, was required for both basal transcription and Ca²⁺_o-mediated transcriptional upregulation. The CaSR mediates Ca²⁺_o-dependent transcriptional upregulation of 1α-hydroxylase and an additional CaSR-mediated mechanism is identified by which Ca²⁺_o can promote luciferase and possibly 1α-hydroxylase breakdown.

Abstract OT-32-01: A phase 2, open-label study of bintrafusp alfa monotherapy in patients with HMGA2-expressing triple-negative breast cancer

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with few targeted treatment options and a poor prognosis. Despite approvals of the anti-PD-L1 monoclonal antibody (mAb) atezolizumab in combination with nab-paclitaxel for unresectable, locally advanced/metastatic TNBC that expresses PD-L1 (tumor-infiltrating immune cells ≥1% of tumor area), many recent studies of other anti-PD-(L)1 therapies in advanced TNBC have shown limited efficacy, likely due to intrinsic therapeutic resistance. Transforming growth factor β (TGF-β), which promotes cancer progression by inducing angiogenesis, fibrosis, and epithelial-mesenchymal transition (EMT), may attenuate the efficacy of or promote resistance to anti-PD-(L)1 therapies. Bintrafusp alfa is a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII receptor (a TGF-β “trap”) fused to a human IgG1 mAb blocking PD-L1. In a cohort of 33 patients with heavily pretreated, advanced TNBC that progressed during/after first-line therapy, bintrafusp alfa was safe and resulted in antitumor activity (NCT02517398). Exploratory biomarker analysis showed that high mobility group AT-hook 2 (HMGA2) expression was 32-fold higher in tumor samples from patients who experienced disease control than from patients who had progressive disease in that cohort. Elevated expression of HMGA2, a protein associated with TGF-β signaling and a known regulator of EMT, is associated with metastasis and poor survival in breast cancer. We present the study design of a phase 2 trial to evaluate the efficacy and safety of bintrafusp alfa in patients with pretreated metastatic TNBC that expresses high levels of HMGA2. Trial Design: This phase 2, multicenter, open-label study will evaluate bintrafusp alfa monotherapy in patients with HMGA2-expressing TNBC that progressed on ≥1 line of systemic therapy for their metastatic disease. Patients will receive bintrafusp alfa 1200 mg every 2 weeks until confirmed progression, unacceptable toxicity, or trial withdrawal. Eligibility Criteria: Patients must have histologically confirmed TNBC defined by ASCO-CAP guidelines (estrogen receptor: immunohistochemistry [IHC] &lt;1%; progesterone receptor: IHC &lt;1%; human epidermal growth factor receptor 2: in situ hybridization nonamplified or IHC 0/1), high tumor HMGA2 expression, ECOG performance status ≤1, and measurable disease by RECIST 1.1. Patients must have experienced disease progression while receiving the most recent therapy prior to enrollment. HMGA2 expression will be centrally determined on archival or fresh tumor tissue by RT-PCR. Prescreening for HMGA2 expression while receiving preceding treatment is allowed; a fresh tumor biopsy prior to study entry may be requested for exploratory biomarker analysis. Patients with prior exposure to immunotherapy are not eligible. Specific Aims: The primary endpoint is independent review committee-assessed objective response rate per RECIST 1.1. Key secondary endpoints include safety, duration of response, durable response rate, progression-free survival, and overall survival. Additional exploratory biomarker characteristics will also be investigated. Statistical Methods: Descriptive statistics, including mean, median, standard deviation, and range, will be used to characterize continuous variables. Frequency counts and percentages will be used to characterize categorical variables. Accrual: Planned enrollment is 29 patients. Contact Information: Leisha A. Emens, MD, PhD Email: emensla@upmc.edu

Citation Format: Leisha A Emens, Margaret E. Gatti-Mays, Joyce O’Shaughnessy, Luc Dirix, Giovanni Faggioni, Andrea Fontana, Jerome Martin-Babau, Christoph Helwig, Alice Huang, Riham Iadevaia, Laureen S Ojalvo. A phase 2, open-label study of bintrafusp alfa monotherapy in patients with HMGA2-expressing triple-negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-32-01.

ScxLin cells directly form a subset of chondrocytes in temporomandibular joint that are sharply increased in Dmp1-null mice

It has been assumed that the secondary cartilage in the temporomandibular joint (TMJ), which is the most complex and mystery joint and expands rapidly after birth, is formed by periochondrium-derived chondrocytes. The TMJ condyle has rich attachment sites of tendon, which is thought to be solely responsible for joint movement with a distinct cell lineage. Here, we used a Scx-Cre ERT2 mouse line (the tracing line for progenitor and mature tendon cells) to track the fate of tendon cells during TMJ postnatal growth. Our data showed a progressive differentiation of Scx lineage cells started at tendon and the fibrous layer, to cells at the prechondroblasts (Sox9 -/Col I +), and then to cells at the chondrocytic layer (Sox9 +/Col I -). Importantly, the Scx + chondrocytes remained as "permanent" chondrocytes to maintain cartilage mass with no further cell trandifferentiation to bone cells. This notion was substantiated in an assessment of these cells in Dmp1 -null mice (a hypophosphatemic rickets model), where there was a significant increase in the number of Scx lineage cells in response to hypophosphatemia. In addition, we showed the origin of disc, which is derived from Scx + cells. Thus, we propose Scx lineage cells play an important role in TMJ postnatal growth by forming the disc and a new subset of Scx + chondrocytes that do not undergo osteogenesis as the Scx - chondrocytes and are sensitive to the level of phosphorous.

Alarmin-activated B cells accelerate atherosclerosis after myocardial infarction via plasma cell-immunoglobulin dependent mechanisms

Introduction

Myocardial infarction (MI) accelerates atherosclerosis and for years greatly increases the risk of recurrent cardiovascular events, such as stroke and MI. B cell-derived autoantibodies produced in response to MI also persist for years.

Purpose

We investigated the role of B cells in adaptive immune responses to MI.

Methods

We used an apolipoprotein-E-deficient (ApoE−/−) mouse model of MI-accelerated atherosclerosis to assess the importance of B cells using loss and gain of function approaches. In loss of function experiment, after inducing an MI we depleted B cells using an anti-CD20 antibody. Gain of function experiments involve transfers of purified MI-B cells from different donor mice, isolated one week after MI, into atherosclerotic ApoE−/− mice.

Results

Depletion of B cells in MI mice prevented immunoglobulin G accumulation in plaques and MI-induced acceleration of atherosclerosis. Adoptive transfer of wildtype MI-B cells into atherosclerotic ApoE−/− mice greatly increased IgG accumulation in plaque and accelerated atherosclerosis in recipient mice. Cytokines that promote humoral immunity were also greatly increased in B cells activated by MI. These cells formed germinal centres within the spleen where they differentiated into antibody-producing plasma cells. Transfer of MI-B cells deficient in Blimp-1, the transcriptional repressor that drives their terminal differentiation to antibody-producing plasma cells failed to accelerate atherosclerosis in recipient mice. Alarmins released from infarcted heart were responsible for activation of B cells via toll-like receptors; transfer of MI-B cells deficient in MyD88, the canonical adaptor protein for inflammatory signaling downstream of toll-like receptors, prevented acceleration of atherosclerosis in recipient mice.

Conclusion

Our data implicate early B cell activation and autoantibodies as a central cause for accelerated atherosclerosis post MI and identifies novel therapeutic strategies towards preventing recurrent cardiovascular events such as MI and stroke.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Health and Medical Research Council of Australia

Phase-Sensitive Second-Harmonic Generation of Electrochemical Interfaces

The interaction between molecular species and charged interfaces plays an indispensable role in a multitude of electrochemical devices. Yet, very little is understood about the nature of this interaction, in particular, the interfacial electric field. Second-order nonlinear spectroscopy such as second-harmonic generation (SHG) can provide chemical information on these interfacial interactions; however, the phase information has received limited attention in electrochemical SHG studies. Here, we demonstrate that the phase of the SHG is essential to the measurement of the electric field at the electrode-electrolyte interface. Our in situ SHG experiment provides strong evidence in support of the parabolic model with complex nonlinear susceptibilities. We conclude that if the absolute phase of the total SHG signal with both χ⁽²⁾ and χ⁽³⁾ contributions can be obtained, it would be possible to measure the potential of zero charge of any electrochemical material.

[Blepharospasm, dry eye and extractable nuclear antigen antibodies (French translation of the article)]

PURPOSE

The goal of this study is to determine a link between benign essential blepharospasm and Sjogren's syndrome by analyzing the presence of extractable nuclear antigens in this population.

METHODS

Seventy-two patients with benign essential blepharospasm (BEB) were included in this study. We eliminated patients with hemifacial spasm or blepharospasm secondary to corneal pathology. We collected the values of the Schirmer I test and the results of the anti-SSA and anti-SSB antibodies.

RESULTS

Our study included 72 patients (144 eyes) whose 62 women (86.1%). Mean age was 74.3 years±10.73. Average Schirmer I test was 3.14mm±4.00mm. Five women (8% of this female population) had positive anti-SSA and SSB antibodies. Their mean age was 65.66 years±13.24 whereas the negative antibody patients had an average age of 75.42±9.27. There was no significant difference between their Schimer I test and the Schirmer I of negative antibody population.

CONCLUSION

This study illustrates the possible association between the presence of Sjögren's syndrome and the occurrence of a BEB justifying the search for anti-SSA and anti SSB in blepharospasm patients.

Abstract 2016: Comparison of HTG-edge targeted RNA sequencing platform with whole transcriptome RNA sequencing for clinical biomarker studies

Purpose HTG EdgeSeq Next Generation Sequencing (NGS) technology is a targeted RNA Sequencing (RNA-Seq) platform based on quantitative nuclease protection chemistry, which requires substantially less sample input than RNA-Seq (one formalin-fixed paraffin-embedded (FFPE) slide versus 4-6 slides). The automated library processor allows fast downstream NGS analysis, making it a promising technology for clinical application and companion diagnostics, especially in samples with limited availability. Given the differences from standard RNA-Seq protocols, it is critical to investigate the performance of HTG EdgeSeq compared to whole transcriptome RNA-Seq technology. We investigated the concordance between HTG EdgeSeq and RNA-Seq on a set of FFPE samples.

Procedure The HTG EdgeSeq Oncology Biomarker Panel (OBP) is comprised of 2558 genes including genes relevant to immuno-oncology and oncology pathways. To evaluate the concordance between the two platforms, 57 FFPE samples from diverse tumor types and varying tumor content (16-100%) were analyzed. One slide was analyzed per sample with the HTG EdgeSeq OBP, while four to six slides were analyzed with whole transcriptome analysis using the Illumina TruSeq Total RNA library kit. A subset of samples and genes were selected for analysis by RT-qPCR using a customized Taqman 15 gene array. Data from the three platforms was analyzed and compared for concordance.

Data Summary Fifty-three samples passed QC on the HTG EdgeSeq platform, while only 29 samples passed a distribution-based QC of the RNA-Seq. For samples that passed QC using both technologies, the median Spearman correlation was 0.73 (25th percentile was 0.70), indicating good, but not linear correlation. In the samples that failed RNA-Seq QC, the median Spearman correlation was 0.30. Probes with low correlation (&lt;0.25) between HTG EdgeSeq and RNA-Seq had an average interquartile range of expression less than 2 log2(CPM) indicating low dynamic range of expression. The HTG EdgeSeq platform showed a tendency towards more detection of low abundance genes indicating either higher sensitivity or higher background. Comparison of RT-qPCR to HTG EdgeSeq showed good sample to sample correlation however, in many cases, genes with low expression in HTG EdgeSeq were undetectable in RT-qPCR leaving the low-end sensitivity of HTG EdgeSeq unclear.

Conclusions HTG EdgeSeq produced fewer QC failures compared to whole transcriptome RNA-Seq while using less tissue. The resulting data showed sound correlation between RNA-Seq, HTG EdgeSeq, and RT-qPCR platforms, especially for genes with moderate to high expression, enabling relatively low risk translation between biomarker platforms. Further, these results were consistent across various cancer types. The characteristics demonstrated in this study support the potential use of HTG EdgeSeq for clinical biomarker applications.

Citation Format: Dennis O'Rourke, Jorge F. Sanchez-Garcia, P. Alexander Rolfe, Alice Huang, Danyi Wang, Juergen Scheuenpflug, Zheng Feng. Comparison of HTG-edge targeted RNA sequencing platform with whole transcriptome RNA sequencing for clinical biomarker studies [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2016.