No Remdesivir Resistance Observed in the Phase 3 Severe and Moderate COVID-19 SIMPLE Trials

Remdesivir (RDV) is a broad-spectrum nucleotide analog prodrug approved for the treatment of COVID-19 in hospitalized and non-hospitalized patients with clinical benefit demonstrated in multiple Phase 3 trials. Here we present SARS-CoV-2 resistance analyses from the Phase 3 SIMPLE clinical studies evaluating RDV in hospitalized participants with severe or moderate COVID-19 disease. The severe and moderate studies enrolled participants with radiologic evidence of pneumonia and a room-air oxygen saturation of ≤94% or >94%, respectively. Virology sample collection was optional in the study protocols. Sequencing and related viral load data were obtained retrospectively from participants at a subset of study sites with local sequencing capabilities (10 of 183 sites) at timepoints with detectable viral load. Among participants with both baseline and post-baseline sequencing data treated with RDV, emergent Nsp12 substitutions were observed in 4 of 19 (21%) participants in the severe study and none of the 2 participants in the moderate study. The following 5 substitutions emerged: T76I, A526V, A554V, E665K, and C697F. The substitutions T76I, A526V, A554V, and C697F had an EC50 fold change of ≤1.5 relative to the wildtype reference using a SARS-CoV-2 subgenomic replicon system, indicating no significant change in the susceptibility to RDV. The phenotyping of E665K could not be determined due to a lack of replication. These data reveal no evidence of relevant resistance emergence and further confirm the established efficacy profile of RDV with a high resistance barrier in COVID-19 patients.

Recommendations for Uniform Variant Calling of SARS-CoV-2 Genome Sequence across Bioinformatic Workflows

Genomic sequencing of clinical samples to identify emerging variants of SARS-CoV-2 has been a key public health tool for curbing the spread of the virus. As a result, an unprecedented number of SARS-CoV-2 genomes were sequenced during the COVID-19 pandemic, which allowed for rapid identification of genetic variants, enabling the timely design and testing of therapies and deployment of new vaccine formulations to combat the new variants. However, despite the technological advances of deep sequencing, the analysis of the raw sequence data generated globally is neither standardized nor consistent, leading to vastly disparate sequences that may impact identification of variants. Here, we show that for both Illumina and Oxford Nanopore sequencing platforms, downstream bioinformatic protocols used by industry, government, and academic groups resulted in different virus sequences from same sample. These bioinformatic workflows produced consensus genomes with differences in single nucleotide polymorphisms, inclusion and exclusion of insertions, and/or deletions, despite using the same raw sequence as input datasets. Here, we compared and characterized such discrepancies and propose a specific suite of parameters and protocols that should be adopted across the field. Consistent results from bioinformatic workflows are fundamental to SARS-CoV-2 and future pathogen surveillance efforts, including pandemic preparation, to allow for a data-driven and timely public health response.

Immunogenic arenavirus vector SIV vaccine reduces setpoint viral load in SIV-challenged rhesus monkeys

HIV affects more than 38 million people worldwide. Although HIV can be effectively treated by lifelong combination antiretroviral therapy, only a handful of patients have been cured. Therapeutic vaccines that induce robust de novo immune responses targeting HIV proteins and latent reservoirs will likely be integral for functional HIV cure. Our study shows that immunization of naïve rhesus macaques with arenavirus-derived vaccine vectors encoding simian immunodeficiency virus (SIVSME543 Gag, Env, and Pol) immunogens is safe, immunogenic, and efficacious. Immunization induced robust SIV-specific CD8+ and CD4+ T-cell responses with expanded cellular breadth, polyfunctionality, and Env-binding antibodies with antibody-dependent cellular cytotoxicity. Vaccinated animals had significant reductions in median SIV viral load (1.45-log10 copies/mL) after SIVMAC251 challenge compared with placebo. Peak viral control correlated with the breadth of Gag-specific T cells and tier 1 neutralizing antibodies. These results support clinical investigation of arenavirus-based vectors as a central component of therapeutic vaccination for HIV cure.

Broad-spectrum activity of bulevirtide against clinical isolates of HDV and recombinant pan-genotypic combinations of HBV/HDV

Background & Aims

Bulevirtide (BLV) is a small lipopeptide agent that specifically binds to the sodium taurocholate cotransporting polypeptide (NTCP) bile salt transporter and HBV/HDV receptor on the surface of human hepatocytes and inhibits HDV and HBV entry. As a satellite virus of HBV, HDV virions are formed after assembly of HDV RNA with the HBV envelope proteins (HBsAg). Because both viruses exist as eight different genotypes, this creates a potential for high diversity in the HBV/HDV combinations. To investigate the sensitivity of various combinations of HBV/HDV genotypes to BLV, clinical and laboratory strains were assessed.

Methods

For the laboratory strains, the different envelopes from HBV genotypes A through H were combined with HDV genotypes 1-8 in cotransfection assays. Clinical plasma isolates were obtained from clinical studies and academic collaborations to maximise the diversity of HBV/HDV genotypes tested.

Results

The mean BLV EC50 against HDV laboratory strains ranged from 0.44 to 0.64 nM. Regardless of HBV and HDV genotypes, the clinical isolates showed similar sensitivities to BLV with mean values that ranged from 0.2 to 0.73 nM.

Conclusions

These data support the use of BLV in patients infected with any HBV/HDV genotypes.

Impact and implications

This study describes the potent activity of BLV against multiple laboratory strains spanning all HBV/HDV A-H/1-8 genotype combinations and the most diverse collection of HDV clinical samples tested to date, including HBV/HDV genotype combinations less frequently observed in the clinic. Overall, all isolates and laboratory strains displayed similar in vitro nanomolar sensitivity to BLV. This broad-spectrum antiviral activity of BLV has direct implications on potential simplified treatment for any patient infected with HDV, regardless of genotype, and supports the new 2023 EASL Clinical Practice Guidelines on HDV that recommend antiviral treatment for all patients with CHD.

EURADOS ISO/IEC 17025 guidance for IMS: suggestions on how to interpret and implement the requirements including examples from accredited laboratories

Individual monitoring of external radiation is an activity usually regulated by national regulatory bodies in most countries. Regulations generally contain technical requirements to be met by the individual monitoring services (IMS), in order to ensure that the measurements are correct and therefore the dosimetry results are reliable. In some countries, the requirements include or even consist of the accreditation of the service according to the standard ISO/IEC 17025: 'General requirements for the competence of testing and calibration laboratories.' It is a fact that accreditation is a growing trend among European IMS as a way to guarantee confidence in their technical competence. The acceptance of the dosimetry results between countries and their indentation in the respective National Dose Registries is facilitated if laboratories conform to the ISO/IEC 17025 standard. In the framework of the activities of EURADOS (European Radiation Dosimetry Group) working group 2 'Harmonization of Individual Monitoring in Europe' and attending to the concern of many European IMS in the process of accreditation, a guide has been prepared. The purpose was to assist and encourage IMS to apply for accreditation and to share the authors' own experience with the process. The guide intends to be a practical reference for IMS on how to interpret and implement the ISO/IEC 17025 requirements to the specific activity of a personal dosimetry service for external radiation, emphasizing those aspects of special interest. It includes examples from dosimetry laboratories already accredited. The major novelties from a new edition of ISO/IEC 17025: 2017 are also identified in the guide. Finally, the guide aims to assist the auditing process, giving examples of auditor's questions and how to show evidence of compliance. The main findings are presented.

Assessment of the Spatial Bio-Distribution of NBTXR3 for Locally Advanced or Borderline-Resectable Pancreatic Ductal Adenocarcinoma (LAPC or BRPC) Patients Undergoing Radiation Therapy

PURPOSE/OBJECTIVE(S)

NBTXR3 is a novel radioenhancer composed of functionalized hafnium oxide nanoparticles that are injected directly into the tumor. An ongoing phase I trial is assessing the application of NBTXR3 in the treatment of locally-advanced or borderline-resectable pancreatic ductal adenocarcinoma, with the primary goal of determining the recommended NBTXR3 dose for a subsequent phase II trial. Using patients from the ongoing phase I trial, we evaluated the spatial bio-distribution of NBTXR3 in the pancreas as function of time and assessed if there is migration of the compound during radiation therapy.

MATERIALS/METHODS

Adult patients with LAPC or BRPC were enrolled. Analysis of 8 patients who underwent CT simulation at least 24 hours after receiving the NBTXR3 intratumoral injection in the pancreatic lesion under general anesthesia guided by an endoscopic ultrasound was conducted. Patients were simulated with and without iodinated intravenous contrast under breath hold, with 3mm CT slice thickness and 50-60cm FoV. A contrast-enhanced CT series was chosen for RT planning purposes. All patients were planned for a 15-fraction IMRT course using 6-MV beam energy, with 45Gy and 37.5Gy dose levels (using a simultaneous integrated boost technique) to gross primary tumor and microscopic disease/regional nodes, respectively. Daily image guidance included either cone-beam CT (CBCT, n = 1) or CT-on-Rails (CTOR, n = 7) and were fused to the planning CT images using Velocity, ver. 3.0.1. The NBTXR3 volume was determined by thresholding the images to 165 HU and 300 HU for CTOR and CBCT images, respectively. Bones, stents, and artifacts were manually removed from the NBTXR3 volume. The volumes for the NBTXR3 and the NBTXR3 overlapping with the GTV for each patient were individually fit to a linear model in R, ver. 4.1.3.

RESULTS

One patient from the CTOR cohort was excluded from analysis due to the small volume of NBTXR3 (0.02 cm3) compared to the rest of the cohort (0.716 - 6.917 cm3). The total volume of NBTXR3 in the CBCT images could not be analyzed due the substantial image artifacts, only the volume overlapping the GTV was calculated. There were no statistically significant changes (p > 0.1 Adj-R2 = 0.99) in the raw volume of NBTXR3 for the duration of the treatment in all CTOR patients. For the NBTXR3 volume overlapping with the GTV, five cases did not present with a volume change during the treatment (p > 0.1 Adj-R2 = 0.99), while one CTOR case had a reduction in volume of about 1.5%/day (p = 0.7), and the CBCT case had a reduction of 3%/day (p < 0.001).

CONCLUSION

The raw volume of NBTXR3 injected in the pancreas did not significantly change over the duration of the three weeks of treatment. We also did not observe significant changes in the NBTXR3 volume overlapping the GTV in most cases. The stability of NBTXR3 was demonstrated during RT.

Phase 1 Trial of SPECT-Guided Liver-Directed Ablative Radiotherapy for Patients with Low Functional Liver Volume

PURPOSE/OBJECTIVE(S)

Traditional liver dose constraints specify that a critical volume of 700 cc of non-tumor liver should be spared from receiving a hepatotoxic dose. We evaluated the safety of liver-directed ablative radiotherapy for patients with hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (iCCA), or liver metastases (LM) with Child-Pugh (CP) A5 liver function at baseline and with low functional liver volume as estimated by Tc-99m sulfur colloid single photon emission computed tomography (SPECT). We hypothesized that functional liver image guidance with SPECT would allow safe delivery of ablative radiotherapy in patients with limited liver volume.

MATERIALS/METHODS

A phase 1 trial with a 3+3 design was conducted to evaluate the safety of comprehensive ablative radiotherapy to the liver disease using escalating functional non-target liver radiation dose constraints. Eligibility criteria included (1) a diagnosis of HCC, iCCA, or LM, (2) prior treatment with irinotecan or oxaliplatin chemotherapy or liver resection, and (3) a minimum functional liver volume of 400 cc as estimated by SPECT using a threshold of 40% maximum intensity. Patients with CP >A5 liver function, prior liver-directed radiotherapy, or prior Yttrium-90 therapy were excluded. The prescription dose was 67.5-75 Gy in 15 fractions or 75-100 Gy in 25 fractions. The volumetric dose constraint for functional non-target liver receiving <24 Gy for 15 fractions or <27 Gy for 25 fractions was determined by the dose level of trial enrollment: level 0 was ≥400 cc and level +1 was ≥300 cc. A level -1 was included if needed. We used standard 15 and 25 fraction dose constraints for other organs at risk. The following dose limiting toxicities (DLTs) were assessed within 6-8 weeks of completing radiotherapy: Grade 3 hypoalbuminemia, increase in INR, increase in bilirubin, or ascites, or Grade 4 hepatic failure or any radiation-related toxicity.

RESULTS

Twelve patients enrolled between February 2016 and June 2022. The median (range) GTV was 36 (2-651) cc. The median CT anatomical non-tumor liver volume was 1584 (764-2699) cc, and the median SPECT functional liver volume was 1117 (570-1928) cc, with a Pearson correlation coefficient of 0.98 (p<0.001). The median non-target SPECT functional liver volume below the volumetric dose constraint was 684 (429-1244) cc. None of the 3 patients treated in dose level 0, and none of the 9 patients treated in dose level +1 experienced any DLTs. The 1-year in-treatment-field control rate was 55%, and 1-year overall survival was 71%.

CONCLUSION

Ablative radiotherapy can be safely delivered using functional SPECT image guidance, which enables sparing lower volumes of functional liver than traditionally accepted in patients with CP A5 liver function. Further evaluation with a phase 2 study is warranted.

No virologic resistance to bulevirtide monotherapy detected in patients through 24 weeks treatment in phase II and III clinical trials for chronic hepatitis delta

BACKGROUND & AIMS

Bulevirtide (BLV) is a HDV/HBV entry inhibitor that is associated with virologic response (responders, HDV-RNA undetectable or ≥2 log10 IU/ml decrease from baseline) in >50% of patients after a 24-week treatment. However, some patients only achieve a <1 log10 IU/ml decline in HDV-RNA after the 24-week treatment (non-responders). Here, we report a viral resistance analysis in participants receiving BLV monotherapy who were non-responders or experienced virologic breakthrough (VB, i.e., two consecutive increases in HDV-RNA of ≥1 log10 IU/ml from nadir or two consecutive HDV-RNA detectable results if previously undetectable) from the phase II MYR202 and phase III MYR301 study.

METHODS

Deep-sequencing of the BLV-corresponding region in HBV PreS1 and of the HDV HDAg gene, as well as in vitro phenotypic testing, were performed for the participant with VB (n = 1) and non-responders (n = 20) at baseline (BL) and Week 24 (WK24).

RESULTS

No amino acid exchanges associated with reduced susceptibility to BLV within the BLV-corresponding region or within HDAg were identified in isolates from any of the 21 participants at BL or at WK24. Although variants (HBV n = 1; HDV n = 13) were detected at BL in some non-responders or in the participant with VB, none were associated with reduced sensitivity to BLV in vitro. Furthermore, the same variant was detected in virologic responders. A comprehensive phenotypic analysis demonstrated that the BLV EC50 values from 116 BL samples were similar across non-responders, partial responders (HDV RNA decline ≥1 but <2 log10 IU/ml), and responders regardless of the presence of HBV and/or HDV polymorphisms.

CONCLUSIONS

No amino acid substitutions associated with reduced sensitivity to BLV monotherapy were detected at BL or WK24 in non-responders or the participant with VB after 24-week BLV treatment.

IMPACT AND IMPLICATIONS

This is the first study investigating the development of resistance in patients treated with BLV. Excluding resistance to BLV as an explanation for an insufficient decrease in HDV-RNA levels during BLV therapy is an important finding for patients, clinicians, and researchers. It demonstrates that BLV has a high barrier to resistance, indicating it is safe and suitable for long-term treatment, although long-term surveillance for resistance should be performed. Our results hint at other still unknown mechanisms as an explanation for the persistence of serum HDV-RNA during inhibition of viral entry.

CLINICAL TRIAL NUMBERS

NCT03546621 and NCT03852719.

Symptoms of dry eye related to the relative humidity of living places

PURPOSE

To investigate the impact of relative humidity (RH) and climate variables of the place of residence on symptoms of dry eye disease (DED) in primary eye care practice.

METHODS

A cross-sectional analysis of the Ocular Surface Disease Index (OSDI) dry eye classification of 1.033 patients [classified as non-DED (OSDI ≤22) and DED (OSDI >22)] was conducted in a multicentre study in Spain. Participants were classified according to the 5-year RH value (data from the Spanish Climate Agency -www.aemet.es) into two groups: those who lived in low RH (<70%) places and those who lived in high RH (≥70%) places. Additionally, differences in daily climate records (EU Copernicus Climate Change Service) were assessed.

RESULTS

The prevalence of DED symptoms was 15.5% (95% CI 13.2%-17.6%). Participants who lived in places with <70% RH showed a higher prevalence of DED (17.7%; 95% CI 14.5%-21.1%; P < 0.01 adjusted for age and sex) than those who lived in places with ≥70% RH (13.6%; 95% CI 11.1%-16.7%) and a closer, but not statistically significant, risk for DED (OR = 1.34, 95% CI 0.96 to 1.89; P = 0.09) than previously described DED risk factors [age older than 50 years (OR = 1.51, 95% CI 1.06 to 2.16; P = 0.02) and female sex (OR = 1.99, 95% CI 1.36 to 2.90; P < 0.01)]. Some climate data showed statistically significant differences (P < 0.05) between participants with DED and non-DED (mean wind gusts; atmospheric pressure; mean and minimum relative humidity); these variables did not significantly increase DED risk (OR close to 1.0 and P > 0.05).

CONCLUSION

This study is the first to describe the impact of climate data on dryness symptomatology in Spain, confirming that participants who live in locations with RH <70% have a higher prevalence (corrected for age and sex) of DED. These findings support the use of climate databases in DED research.

Initial progress of the magnetic diagnostics of the MAST-U tokamak

MAST Upgrade has just begun its third physics campaign in April of 2023. The set of magnetic probes used to diagnose the magnetic field and currents on MAST Upgrade are described, and their calibration procedures are outlined including calculation of uncertainties. The median uncertainty in the calibration factors of the flux loops and pickup coils are calculated as 1.7% and 6.3%. The arrays of installed instability diagnostics are described, and the detection and diagnosis of a specimen MHD mode are demonstrated. Plans for the improvement of the magnetics arrays are outlined.

Uncertainties in the adaptation of alpine pastures to climate change based on remote sensing products and modelling

Over the last century, the management of pastoral systems has undergone major changes to meet the livelihood needs of alpine communities. Faced with the changes induced by recent global warming, the ecological status of many pastoral systems has seriously deteriorated in the western alpine region. We assessed changes in pasture dynamics by integrating information from remote-sensing products and two process-based models, i.e. the grassland-specific, biogeochemical growth model PaSim and the generic crop-growth model DayCent. Meteorological observations and satellite-derived Normalised Difference Vegetation Index (NDVI) trajectories of three pasture macro-types (high, medium and low productivity classes) in two study areas - Parc National des Écrins (PNE) in France and Parco Nazionale Gran Paradiso (PNGP) in Italy - were used as a basis for the model calibration work. The performance of the models was satisfactory in reproducing pasture production dynamics (R² = 0.52 to 0.83). Projected changes in alpine pastures due to climate-change impacts and adaptation strategies indicate that: i) the length of the growing season is expected to increase between 15 and 40 days, resulting in changes in the timing and amount of biomass production, ii) summer water stress could limit pasture productivity; iii) earlier onset of grazing could enhance pasture productivity; iv) higher livestock densities could increase the rate of biomass regrowth, but major uncertainties in modelling processes need to be considered; and v) the carbon sequestration potential of pastures could decrease under limited water availability and warming.

Hepatitis B virus haplotype number at baseline is a predictive marker of functional cure during antiviral therapy for patients with genotypes A and D HBeAg-positive chronic hepatitis B

BACKGROUNDS AND AIMS

We investigated associations between hepatitis B virus (HBV) genome-length haplotype number (HN) at baseline in subjects with HBeAg-positive chronic hepatitis B (CHB), and the likelihood of achieving functional cure during direct-acting antiviral therapy METHOD: We analysed 86 HBeAg-positive baseline samples from patients with HBV genotypes A and D who were enrolled in a Phase II trial of tenofovir disoproxil fumarate (TDF) to determine if HN was a biomarker of HBsAg loss during therapy. Findings were validated using baseline samples from 181 patients with HBV genotypes A and D from an independent clinical trial utilising TDF or tenofovir alafenamide therapy in HBeAg-positive CHB.

RESULTS

In the HBeAg-positive test cohort, patients with genotypes A or D and ≤2 haplotypes had a minimum of 21-fold higher likelihood of achieving HBsAg loss on TDF. Baseline HN (p < 0.0001) was a stronger predictor of HBsAg loss on therapy than HBsAg titre (p = 0.03), HBeAg titre (p = 0.0002), or the presence of HBV basal core promoter (A1762T, p = 0.0379 and G1764A, p = 0.0176) or G1896A precore mutations (p = 0.0218). This finding was validated in the independent validation cohort. HN was statistically higher in patients with HBV genotypes B or C infection compared to genotypes A and D.

CONCLUSION

Baseline HN ≤2 predicts which patients with HBV genotypes A or D will more likely progress to functional cure on current direct-acting antiviral therapy, with greater accuracy than current biomarkers including baseline HBsAg and HBeAg titre.

Patient Satisfaction with Upper and Lower Complete Dentures: A Service Evaluation Report

PURPOSE

The purpose of this questionnaire-based service evaluation was to assess patient satisfaction with complete dentures provided in a dental teaching hospital.

METHODS

Patients completed the self-administered questionnaire before, immediately after, and 2-months following provision of new complete dentures. The questionnaire consisted of the following sections: Patient characteristics, current denture history and satisfaction with the fit of upper/lower complete dentures, chewing ability, speech, and aesthetics. Descriptive analysis, chi-square test, student t-test, and 2-way-ANOVA were performed on satisfaction levels pre-and post-treatment to assess denture fit, chewing ability, speech, and appearance. Age and gender-wise satisfaction levels along with correlations and associations between patient satisfaction levels and various factors were assessed.

RESULTS

147 participants, including 91 males (61.9%) and 56 females (38.1%) completed the study. A statistically significant improvement in satisfaction scores was seen post-treatment in all domains (p⟨0.05), with most respondents showing great satisfaction. Overall, satisfaction levels were: Upper complete denture fit (82%), appearance (87%), speech (67%), chewing ability and lower complete denture fit (39%). A strong positive correlation was observed between the number of previous dentures used and patient satisfaction with upper denture fit (R=1).

CONCLUSION

Denture replacement positively impacts the satisfaction of patients and improves complete denture acceptance.

Sequence characterization of extracellular HBV RNA in patient plasma

Antiviral nucleos(t)ide analogue therapies inhibit HBV replication and suppress the HBV DNA levels in patients with chronic HBV infection. Since HBV RNAs are expressed from cccDNA or HBV integrated sequences, independently of viral genome replication, levels of HBV RNAs in plasma may remain high following treatment with nucleos(t)ide analogue. Thus, HBV RNAs have been proposed to be used as a viral biomarker for treatment outcome and disease progression. Recent investigations of plasma HBV RNAs described the presence of full length as well as subgenomic forms of RNA. To support the usage of plasma HBV RNAs as a viral biomarker, further understanding of HBV RNA composition in clinical samples is needed. Here, sequence of extracellular HBV RNAs was characterized in plasma samples of patients with chronic HBV infection using two independent RNA amplification methods that do not use HBV-specific primers for amplification: total RNA (NuGEN RNAseq) and mRNA (TruSeq RNAseq). Sequencing coverage was obtained across the full length of HBV genome for both methods, confirming the presence of full-length HBV RNA in plasma. The sequence of HBV RNA was nearly identical to plasma HBV DNA sequence in each sample with only 0-14 (median 4) mismatches over 3 kb. Thus, sequence of HBV RNA plasma reflects the intrahepatic viral reservoir and can be used for monitoring of sequence variants such as resistance in clinical trials. Additionally, RNA splice forms, different polyA tails start positions and presence of HBV-human chimeric transcript were identified.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

Recruitment and organising 3rd year pharmacy undergraduates into summer placements in primary care in Southwest England

Introduction

Primary care is facing a workforce shortage, especially in Southwest England (SW).1 Funding for clinical pharmacist roles in GP has an impact on community pharmacy with pharmacists leaving to take up PCN positions.2 SW has higher rate of vacancies in than nationally.3 Oriel data showed that fill rate for split foundation training placements in GP is high, however, in SW is significantly low.

Aim

To increase recruitment of future pharmacists in SW by offering pharmacy undergraduates paid 5-week summer placements in GP or GP/community pharmacy partnership, gaining primary care experience, showcasing benefits of cross-sector working and encouraging development of partnerships for increased cross-sector training placements.

Objectives

Students enjoy SW area placement, Students recommend placement to other students, Students preference GP foundation placement, Supervisors express interest in a summer placement for 2022, Supervisors express interest in the GP split trainee pharmacist programme.

Methods

Expressions of interest (EOIs) sought from primary care placements in SW and 16 sites selected. Applicants shortlisted and interviewed online. 16 offered placements based on preference of location. Funding by HEE South reimbursed for student’s wages. Planning booklets provided to GPs, workbooks to students and online induction attended. During the placement, students completed an audit and case-based discussion, shadowed healthcare professionals, assisted administration and pharmacy tasks and practised basic procedural skills. Students attended end-of-placement event to share learning and sent questionnaire focusing on enjoyment of the placement and likelihood of returning to the Southwest and primary care for future employment. Supervisors sent questionnaire separately focusing on likelihood to partake in future. Questionnaires were sent, completed and analysed via Jisc. Ethics approval was not required.

Results

10 students and 11 supervisors completed the survey. 60% students enjoyed SW. 90% students would recommend placement to other students and 90% would like to see them in other areas. 70% students very likely to or definitely would apply for GP foundation placement. 63% supervisors benefitted from having a student and 81% would recommend having summer placement student. 55% supervisors would definitely EOI in future summer placement programme and 55% would definitely EOI in GP split foundation programme. 25% students chose GP/Community placements in SW, 18% other placements in SW, 12% GP placements in other regions. Oriel fill rates in SW increased from 36.67% in 2020 to 39.30% in 2021, GP/Community placements remained the same in 2021 at 28.2% and community placements increased in from 18.14% in 2020 to 18.75% in 2021.

Discussion/Conclusion

The students enjoyed their placements and would recommend to other students. Supervisors found having students useful and would have a student in the future. Although some students were successful in securing a placement in SW for foundation training, due to nature of Oriel it’s not possible to determine how many preferenced SW and GP split programme, this is a limitation to the evaluation. Oriel fill rates didn’t increase for SW community/GP placements as desired, however this was a very small cohort. This pilot will be repeated summer 2022 so fill rates can be evaluated in 2023.

References

1. NHS. The NHS Long Term Plan. Long Term Plan. [Online] 2019. Available from: https://www.longtermplan.nhs.uk/wp-content/uploads/2019/08/nhs-long-term-plan-version-1.2.pdf.

2. BMA. Investment and Evolution: A five year gramework for GP contract reform to implement the NHS long term plan. England NHS. [Online] 2019. Available from: https://www.england.nhs.uk/wp-content/uploads/2019/01/gp-contract-2019.pdf.

3. Community Pharmacy Workforce Development Group. A Review of the Community Pharmacy Workforce. Community Pharmacy Workforce. [Online] 2021. Available from: https://communitypharmacyworkforce.files.wordpress.com/2021/06/cpwdg-report-a-review-of-the-community-pharmacy-workforce-final.pdf.

Towards increased accuracy and reproducibility in SARS-CoV-2 next generation sequence analysis for public health surveillance

During the COVID-19 pandemic, SARS-CoV-2 surveillance efforts integrated genome sequencing of clinical samples to identify emergent viral variants and to support rapid experimental examination of genome-informed vaccine and therapeutic designs. Given the broad range of methods applied to generate new viral genomes, it is critical that consensus and variant calling tools yield consistent results across disparate pipelines. Here we examine the impact of sequencing technologies (Illumina and Oxford Nanopore) and 7 different downstream bioinformatic protocols on SARS-CoV-2 variant calling as part of the NIH Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) Tracking Resistance and Coronavirus Evolution (TRACE) initiative, a public-private partnership established to address the COVID-19 outbreak. Our results indicate that bioinformatic workflows can yield consensus genomes with different single nucleotide polymorphisms, insertions, and/or deletions even when using the same raw sequence input datasets. We introduce the use of a specific suite of parameters and protocols that greatly improves the agreement among pipelines developed by diverse organizations. Such consistency among bioinformatic pipelines is fundamental to SARS-CoV-2 and future pathogen surveillance efforts. The application of analysis standards is necessary to more accurately document phylogenomic trends and support data-driven public health responses.

204 DEDICATED NURSING HOME SERVICE IN A TERTIARY HOSPITAL: EFFECT ON ADMISSION NUMBERS AND LENGTH OF STAY

Background

In 2019 a dedicated Nursing Home (NH) in-patient service was established in a tertiary hospital, comprising a Consultant Geriatrician, clinical nurse specialist, NCHD and administrative support. All NH residents over 65 with medical diagnoses were admitted by the NH team who also provide a consult service for NH residents under other specialties.

Methods

Data were sourced from the Hospital Inpatient Enquiry system on length of stay of patients identified as admitted from a nursing home compared to those admitted under the NH team and their average lengths of stay over 2019-2021.

Results

In 2019, 749 NH residents were admitted to hospital with an average length of stay (ALOS) of 7.93 days, the NH inpatient service was established in July 2019 and showed a reduction of ALOS from 9.25 to 6.6 days in the 6 months following its establishment (29% difference.) In 2020, 707 NH residents were admitted with 352 admitted under the NH team. The ALOS of NH residents admitted under the NH team was 5.66 days in 2020 compared to 8.65 overall (35% difference.) In 2021, 765 NH residents were admitted with 402 under the NH team. ALOS of NH residents admitted under the NH team was 5.33 days in 2021 compared to 8.28 overall (36% difference.)

Conclusion

Within six months of its commencement the dedicated NH service had decreased length of stay by 29%. The average length of stay across all services has decreased year on year from 6.6 to 5.3 days from 2019 to 2021. The ALOS in the total cohort (including residents admitted surgically and those under 65) was 29-36% higher. Though difficult to accurately compare these cohorts due to different presenting diagnoses and medical backgrounds in those admitted surgically or those under 65, the overall reduction in length of stay over the three years does highlight the benefit from this dedicated service.

203 TRANSITIONS TO LONG-TERM CARE: EXPERIENCE OF A COHORT OF COMMUNITY-DWELLING OLDER ADULTS RECEIVING INTEGRATED CARE

Background

Data from the Nursing Home support scheme 2018 (NHSS) shows the majority of applications to the NHSS come from acute hospitals (44%) followed by referrals from the community (38%). We examined this transition in a cohort of community dwelling older adults to assess how many transition from home to nursing home and, when admission to nursing home from hospital occurred, the indications for same.

Methods

Retrospective examination of Integrated Care Team (ICT) and Acute Hospital data from 2019 in respect of a cohort of older adults. Transitions in care to nursing home including residence at time of admission, last acute hospital presentation prior to nursing home admission and commencement of NHSS application recorded.

Results

319 patients referred to the integrated care service in 2019, average age 81 and 58% female, predominantly from outpatient clinics in the Medicine for the Older Person’s service. 47 patients had moved to nursing home; within this cohort 14 (29.7%) transitioned from home, 28 (59.6%) transitioning after acute hospital admission. Main reasons for presentation to hospital were: Intercurrent acute illness (n=11); Falls (n=6); progression of dementia (n=4). Fair Deal application commenced in community by ICT in 20 of the 47 (42.5%) patients including 8 of 28 patients (28.5%) admitted to hospital prior to moving to nursing home.

Conclusion

This preliminary evaluation highlights the importance of advance care planning in this population when acute hospital admissions can be difficult to predict. Involvement of the ICT can help this transition and lead to shorter hospital stays.

160 A CLOSED-LOOP AUDIT EXAMINING THE USE OF PROPHYLACTIC ANTI-COAGULATION IN OLDER ADULTS ADMITTED TO A SPECIALIST GERIATRIC SERVICE

Background

Guidelines recommend prescription of Prophylactic Anticoagulation (PA) to all hospitalized older adults unless a contraindication exits. In many cases this does not happen at the time of admission increasing the risk of thromboembolic events. We aimed to assess the use of PA across the medicine for the geriatric service of a level 3 hospital (average daily census of service 120) then use quality improvement to achieve our goal of 95% prescription of prophylactic anticoagulation when appropriate.

Methods

Medication kardexes and clinical notes were reviewed to collect variables including age, length of stay, creatinine clearance, weight, mobility status, use and dose of antithrombotic medications and documentation of reason if not prescribed. Following initial data collection, cause and effect analysis was performed to identify reasons for under-prescription and small tests of change were conducted across 4 PDSA cycles before data collection was repeated.

Results

Initial data collection revealed that only 80% of older adults admitted to the service were receiving prophylactic anticoagulation. Cause and effect analysis identified many reasons for failure to prescribe PA including inadequate history taking, lack of clinician education and training, poor documentation, lack of handover between clinicians, failure to complete medication reconciliation on admission and lack of pharmacy support on some wards. Each of these contributory factors were addressed in turn. After a month of QI activities prescription of PA improved to 83% and by 3 months 98.1% (104/106) of patients were receiving PA with only 2 patients for whom PA was not prescribed without clear documentation of the reason.

Conclusion

Sustained quality improvement resulted in a culture change across our service improving rates of appropriate prescription of PA and raising the quality of care delivered to older adults. This model of quality improvement is now being replicated across our department to address other gaps in service delivery.

OP0221 EFFICACY OF SECUKINUMAB IN ENTHESITIS-RELATED ARTHRITIS: RESULTS FROM A RANDOMISED, DOUBLE-BLIND, PLACEBO-CONTROLLED, TREATMENT WITHDRAWAL, PHASE 3 STUDY (JUNIPERA)

Background

Enthesitis-related Arthritis (ERA) is a category of juvenile idiopathic arthritis (JIA) characterised by heterogeneous and insidious manifestations comprising axial and/or peripheral arthritis, and enthesitis.1 Secukinumab (SEC) demonstrated efficacy and safety in both ERA and juvenile psoriatic arthritis (JPsA) in the JUNIPERA trial.2

Objectives

To evaluate the rate of flare risk reduction and efficacy of SEC on axial and peripheral manifestations in patients (pts) with active ERA.

Methods

ERA pts (2 to <18 years of age) with active disease (both ≥3 active joints and ≥1 active enthesitis site) were included. In the open-label (OL) treatment-period (TP)1, s.c. SEC (75/150 mg in pts <50/ ≥50 kg) was administered at baseline (BL), and at Week (Wk) 1–4, 8 and 12. Pts who achieved at least JIA-ACR30 response at Wk 12 were randomised into the double-blinded TP2 to continue SEC or placebo (PBO) every 4 wk until a disease flare, or up to Wk 100. The primary endpoint was time to flare in ERA and JPsA pts. The juvenile spondyloarthritis disease activity Index (JSpADA) is a disease activity assessment tool that contains 8 items to measure axial and peripheral disease activity.3 Evaluation of axial and peripheral manifestations at the end of TP1 and TP2 in pts who experienced these symptoms at BL included modified Schober test (lumbar flexion), inflammatory back pain, FABER (Flexion, ABduction, External Rotation) test, JIA-ACR responses, Juvenile Arthritis Disease Activity Score (JADAS)-27, and resolution of enthesitis and dactylitis for peripheral disease. These outcomes were also used to assess JIA disease course at the end of TP2.

Results

A total of 52/86 (60.5%) pts with ERA were enrolled in the OL period TP1 (mean age, 13.7 years; male, 78.8%). In total, 51/52 (98.1%) pts completed TP1 and 41/44 (93.2%) completed TP2. At BL, mean JADAS-27 was 14.8, mean JSpADA index was 3.9, mean enthesitis and dactylitis counts were 2.7 and 0.4, respectively, mean number of active joints was 6.2 and of mean joints with limited range of motion 4.9. The relative risk reduction of experiencing a disease flare in TP2 was 55% (HR 0.45, 95% CI: 0.16–1.28, p=0.075) in ERA pts (Figure 1). The overall axial and peripheral disease symptoms improved over time and are presented in the Table 1. At the end of TP1, 84.6% (44/52) of pts achieved JIA-ACR 30 and 65.4% (34/52) achieved JIA-ACR 70. Clinically relevant reduction of functional ability as assessed by Childhood Health Assessment Questionnaire (CHAQ) also occurred (see Table 1).

Table 1.

Resolution of axial and peripheral disease symptoms and JIA ACR responses at the end of TP1 and 2

Clinical response, mean (SD) change from BL (unless otherwise stated)TP1-Wk 12End of TP2*SEC (N=52)SEC (N=22)PBO (N=22)JSpADA index−2.4 (1.7)−2.7 (1.7)−2.3 (2.1)JSpADA Schöber, %58.3100.0100.0Inflammatory back pain, %77.8100.050.0FABER test, %52.6100.083.3Clinical sacroiliitis, %53.3100.050.0Enthesitis−2.2 (1.9)−2.5 (2.1)−1.3 (1.8)Dactylitis−0.2 (0.8)−0.2 (1)−0.1 (0.4)JIA ACR30, %84.690.968.2JIA ACR50, %78.881.868.2JIA ACR70, %65.468.254.5JIA ACR90, %32.745.550.0JIA ACR100, %26.936.445.5Inactive disease, %38.550.050.0CHAQ−0.5 (0.5)−0.6 (0.7)−0.4 (0.5)CRP, median (SD) change from BL−1.8 (38.7)−5.8 (38.3)0 (35.9)JADAS-27−9.6 (7.5)−11.0 (8.9)−7.6 (8.9)Resolution of enthesitis#, %72.378.683.3Resolution of dactylitis#, %5066.70

*End of TP2 is based on individual pts’ last visit at TP2. #At BL, in TP1, enthesitis (n= 46); dactylitis (n=5). In TP2, no. of pts who had presence at BL and showed complete resolution at the end of TP2: enthesitis, SEC 14, PBO 18; dactylitis, SEC 3, PBO, 0. CRP, C-reactive protein

Conclusion

In pts with ERA, SEC demonstrated longer time to disease flare vs PBO and exhibited rapid and sustained improvement of axial and peripheral manifestations up to Wk 104.

References

[1]Pagnini I, et al. Front Med 2021;8:6673052.

[2]Brunner H, et al. Arthritis Rheumatol 2021;73 (suppl 10).

[3]Weiss PF, et al. Arthritis Care Res 2014;66:1775-82.

Disclosure of Interests

Nicolino Ruperto Speakers bureau: Eli Lilly, GlaxoSmith and Kline, Pfizer, SOBI and UCB, Paid instructor for: Eli Lilly and Pfizer, Consultant of: Ablynx, Amgen, Astrazeneca-Medimmune, Aurinia, Bayer, Bristol Myers and Squibb, Cambridge Healthcare Research (CHR), Celegene, Domain therapeutic, Eli Lilly, EMD Serono, GlaxoSmith and Kline, Idorsia, Janssen, Novartis, Pfizer, SOBI and UCB, Grant/research support from: Bristol Myers and Squibb, Eli Lilly, F Hoffmann-La Roche, Novartis, Pfizer and SOBI, Elena Chertok: None declared, Joke Dehoorne Speakers bureau: Abbvie, Roche, Consultant of: Abbvie, Roche, Pfizer, Grant/research support from: Abbvie, Roche, Gerd Horneff Speakers bureau: Novartis, Pfizer, Janssen, Grant/research support from: Pfizer, Novartis, Roche, MSD, Tilmann Kallinich Speakers bureau: Roche, Ingrid Louw Speakers bureau: Pfizer, Abbvie, BMS, Consultant of: Pfizer, Abbvie, Janssen, Amgen and Cipla, Sandrine Compeyrot-Lacassagne: None declared, Bernard Lauwerys Employee of: UCB Pharma, Neil Martin: None declared, Katherine Marzan Grant/research support from: Novartis, Sanofi, William Knibbe Speakers bureau: Novartis, Amgen, UCB, Abbvie, Ruvie Martin Shareholder of: Novartis, Employee of: Novartis, Xuan Zhu Shareholder of: Novartis, Employee of: Novartis, sarah whelan Shareholder of: Novartis, Employee of: Novartis, Luminita Pricop Shareholder of: Novartis, Employee of: Novartis, Alberto Martini Speakers bureau: Aurinia, Bristol Myers and Squibb, Eli Lilly, EMD, Janssen, Pfizer, Roche and Serono, Consultant of: Aurinia, Bristol Myers and Squibb, Eli Lilly and EMD, Daniel J Lovell Consultant of: Astra Zeneca, Boehringer Ingelheim, GSK, Hoffman LaRoche, Novartis, UBC, Grant/research support from: Astra Zeneca, Boehringer Ingelheim, GSK, Hoffman LaRoche, Novartis, UBC, Hermine Brunner Consultant of: Novartis, Grant/research support from: Novartis

Brief Report: Bictegravir/Emtricitabine/Tenofovir Alafenamide Efficacy in Participants With Preexisting Primary Integrase Inhibitor Resistance Through 48 Weeks of Phase 3 Clinical Trials

BACKGROUND

Preexisting drug resistance limits the utility of HIV antiretroviral therapy. Studies have demonstrated safety and efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF), including in patients with M184V/I substitutions.

SETTING

We investigated virologic outcomes through 48 weeks of B/F/TAF treatment in individuals with preexisting primary integrase strand transfer inhibitor resistance (INSTI-R).

METHODS

Preexisting INSTI-R was retrospectively evaluated from 7 B/F/TAF studies. INSTI-R was assessed by historical genotypes and/or baseline RNA or DNA sequencing. Viral loads were measured at all visits.

RESULTS

Preexisting primary INSTI-R substitutions were detected in 20 of the 1907 participants (1.0%). The 20 participants were predominantly male (75%), were Black (65%), had HIV-1 subtype B (85%), and had baseline median CD4 counts of 594 cells/mm3 and median age of 52 years. Most of the participants (n = 19) were virologically suppressed at baseline and had one primary INSTI-R substitution, E92G, Y143C/H, S147G, Q148H/K/R, N155S, or R263K, +/-secondary substitutions. All suppressed participants maintained virologic suppression throughout 48 weeks without any viral blips. One treatment-naive participant had virus with Q148H+G140S that was fully sensitive to bictegravir but only partially to dolutegravir (phenotype <2.5-fold change and >4-fold change, respectively). With a baseline viral load of 30,000 copies/mL, this participant was virologically suppressed by week 4 and maintained <50 copies/mL through week 48.

CONCLUSIONS

This small cohort with primary INSTI-R achieved and/or maintained virologic suppression through 48 weeks of B/F/TAF treatment. Consistent with the potent in vitro activity of bictegravir against most INSTI-R patterns, B/F/TAF may be a potential treatment option for patients with select preexisting INSTI-R, if confirmed by further studies.

Evaluation of HIV-1 reservoir size and broadly neutralizing antibody susceptibility in acute antiretroviral therapy-treated individuals

OBJECTIVE

Persistence of the viral reservoir is the main barrier to curing HIV. Initiation of ART during acute HIV infection can limit the size and diversity of the reservoir. In depth characterization of the reservoir in individuals who initiate ART during acute infection will be critical for clinical trial design and cure strategies.

METHODS

Four cohorts with participants who initiated ART during acute infection or during chronic infection were enrolled in a cross-sectional, noninterventional study. Viral reservoir was evaluated by the Intact Proviral DNA Assay (IPDA), the Total HIV DNA Assay (THDA) and the Quantitative Viral Outgrowth Assay (QVOA). Viral diversity and susceptibility to V3-glycan bNAbs were determined by genotyping of the viral envelope gene.

RESULTS

Participants who initiated ART during the acute Fiebig I-IV stages had lower level of total HIV DNA than participants who initiated ART during chronic infection whereas no difference was observed in intact HIV DNA or outgrowth virus. Participants who initiated ART during Fiebig I-IV also had lower viral diversity and appeared to have higher susceptibility to bNAbs than participants initiating ART during chronic infection.

CONCLUSION

Individuals initiating ART during Fiebig I-IV had small viral reservoirs, low viral diversity, and high susceptibility to bNAbs, and would be an optimal target population for proof-of-concept HIV cure trials.

Targeted long-read sequencing reveals clonally expanded HBV-associated chromosomal translocations in patients with chronic hepatitis B

Background & Aims

Methods

Results

Conclusions

Lay summary

•

Fresh frozen liver biopsies from patients with CHB were subjected to targeted long-read RNA and DNA sequencing.

•

Inter-chromosomal translocations associated with HBV integration events detected in one-third of patients.

•

Chromosomal translocations were unique to each biopsy sample, suggesting that each originated randomly.

•

A larger fraction of the HBV transcriptome originates from cccDNA in patients who are HBeAg-positive.

Phenotypic resistance to lenacapavir and monotherapy efficacy in a proof-of-concept clinical study

BACKGROUND

Lenacapavir in vitro resistance selections identified seven mutations in HIV-1 capsid protein (CA) associated with reduced susceptibility.

OBJECTIVES

To analyse lenacapavir activity against lenacapavir-associated resistance mutations in multiple assays. We also report Day 10 resistance analyses conducted in a Phase 1b study of lenacapavir (Study 4072) in people with HIV (PWH).

METHODS

Mutations were inserted in a proviral DNA clone by site-directed mutagenesis, and viruses (n = 12) were generated by transfection. Sequences were used to generate single-cycle (SC) test vectors that were evaluated in a Gag-Pro assay, and replicative viruses were tested in a multicycle (MC) MT-2 assay to determine lenacapavir susceptibility. Study 4072 was a Phase 1b, double-blinded, placebo-controlled, dose-ranging, randomized study of lenacapavir in untreated PWH. Participants received a single dose of lenacapavir (up to 750 mg) or placebo (10 day monotherapy). CA resistance was characterized using genotypic and/or phenotypic assays.

RESULTS

Lenacapavir susceptibility in the SC assay showed an inverse relationship between replication capacity and resistance. In Study 4072, all 29 participants receiving lenacapavir showed a robust virological response with no rebound. At baseline, no participant had resistance mutations to lenacapavir, and all had WT susceptibility to lenacapavir. Post-monotherapy analyses revealed the emergence of CA mutation Q67H at Day 10 in two participants.

CONCLUSIONS

In vitro assays confirmed that increased resistance to lenacapavir was associated with decreased replication capacity of mutant viruses. In the clinical study no pre-existing lenacapavir resistance was detected. Emergence of Q67H occurred at exposures below the dose used in current Phase 2/3 studies. These results support development of lenacapavir as an antiretroviral agent.

Static postural differences between male and female equestrian riders on a riding simulator

This study aimed to compare static posture of male and female riders on a riding simulator. Ten female and five male riders underwent a 5 min standardised exercise programme on the simulator, they were then videoed for 10 s from each the left, right, and rear views whilst stationary on the simulator. Two-dimensional kinematic analysis of the videos showed that male riders had a more neutrally positioned pelvis in the sagittal plane (median left: 6.47°, right: 5.24°) with females demonstrating a posterior pelvic tilt (L: 14.04°, R: 13.55°). Females showed significantly greater pelvic obliquity (median female: 1.99°, male: 0.73°), trunk lean (F: 1.60°, M: 0.43°), and shoulder tilt (F: 1.79°, M: 0.57°) in the frontal plane, demonstrating an overall greater postural asymmetry. Previous studies of elite riders have shown a more anteriorly rotated pelvis to be more desirable. Symmetry of riding position is favourable as it allows movements to be performed with ease and ensures even force distribution through the saddle to the horse. Male riders may therefore have a biomechanical advantage over females when it comes to maintaining a desirable riding position. This research should now be extended to study riders on the horse in motion.

73. Interim Resistance Analysis of Long-Acting Lenacapavir in Treatment-Naïve People with HIV at 28 Weeks

Background

Lenacapavir (LEN) is a first-in-class HIV-1 capsid (CA) inhibitor in clinical development for treatment and prevention of HIV-1 infection. CALIBRATE is an ongoing, phase 2 clinical study evaluating subcutaneous (SC) or oral LEN, in combination with other antiretrovirals, in treatment-naïve people with HIV-1. High rates of virologic success (HIV-1 RNA < 50 copies/mL) were achieved with LEN-based regimens by FDA Snapshot analysis at Week 28. Here, we present interim resistance analyses through Week 28.

Methods

Participants were randomized (2:2:2:1) to treatment groups (TG) (Figure): SC LEN + oral daily emtricitabine/tenofovir alafenamide (F/TAF); at Week 28, participants switch F/TAF to oral TAF (TG-A) or bictegravir (B, BIC) (TG-B); oral daily LEN + F/TAF (TG-C), or oral daily B/F/TAF (TG-D). Genotypic analyses (population sequencing) of HIV-1 reverse transcriptase and integrase, and genotypic (deep sequencing)/phenotypic analyses for CA were performed at screening; genotypic and phenotypic analyses were conducted at confirmed virologic failure.

Figure

CALIBRATE Study Design

Results

182 participants were randomized and dosed in TG-A to D (n=52, 53, 52, 25). Most participants had subtype B HIV-1 (92.9%). Sequence analysis of baseline samples found 65% of amino acid residues were conserved with < 1% variation across CA overall, and 55% of residues were fully conserved. No mutations were detected at 6 positions in CA associated with reduced susceptibility to LEN in vitro; residues were fully conserved at 5 positions (L56, M66, Q67, K70, N74), and < 2% variation was observed at 1 position (T107). Three participants met the criteria for resistance analysis: 2 participants resuppressed to < 50 copies/mL while continuing treatment. One participant on SC LEN + F/TAF developed emergent resistance to LEN (Q67H+K70R) and emtricitabine (M184M/I), followed by resuppression after starting dolutegravir, zidovudine + lamivudine, tenofovir disoproxil fumarate.

Conclusion

Emergent resistance to LEN was uncommon in treatment-naïve participants receiving SC or oral LEN (0.6%, 1/157). These interim resistance findings support the ongoing evaluation of LEN for treatment and prevention of HIV.

Disclosures

Laurie VanderVeen, PhD, Gilead Sciences (Employee, Shareholder) Nicolas Margot, MA, Gilead Sciences (Employee, Shareholder) Vidula Naik, MSc, Gilead Sciences (Employee, Shareholder) Silvia Chang, Masters, Gilead Sciences, Inc (Employee, Shareholder) Ross Martin, PhD, Gilead Sciences, Inc (Employee, Shareholder) Hadas Dvory-Sobol, PhD, Gilead Sciences (Employee, Shareholder) Martin Rhee, MD, Gilead Sciences (Employee, Shareholder) Christian Callebaut, PhD, Gilead Sciences (Employee, Shareholder)

629. High Efficacy of Bictegravir/Emtricitabine/Tenofovir Alafenamide (B/F/TAF) in African American Adults with HIV Including Those with Preexisting Resistance, Viral Blips, and Suboptimal Adherence

Background

BRAAVE 2020 demonstrated the efficacy of switching to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) among African American adults with suppressed HIV through Week (W) 48 (Figure 1). We present resistance, viral blips, adherence, and virologic outcomes through W72.

Figure 1. BRAAVE 2020 study design (phase 3, randomized, open-label, multicenter [USA], active-controlled study) and virologic suppression at weeks 24 and 48

Methods

Enrollment criteria permitted NNRTI resistance (-R), PI-R, and certain NRTI-R (M184V/I allowed; K65R/E/N, ≥3 thymidine analog mutations [TAMs], or T69-insertions excluded) and excluded known primary INSTI-R. Preexisting drug resistance was assessed with historical genotypes and retrospective baseline proviral DNA genotyping. Adherence was calculated by pill count. Viral blips (transient HIV-1 RNA ≥50 copies/mL) and outcomes based on last available on-treatment HIV-1 RNA were assessed.

Results

489 participants received B/F/TAF and had ≥1 post-switch HIV-1 RNA measurement. Baseline genotypic data from cumulative historical and/or proviral genotypes were available for 96% (468/489) in protease/reverse transcriptase and 93% (453/489) in integrase. Preexisting NRTI-R, M184V/I, ≥1 TAMs, NNRTI-R, and PI-R were observed in 15% (68/468), 11% (50/468), 8% (36/468), 22% (101/468), and 13% (61/468), respectively. Primary INSTI-R was detected post-randomization in 2% (11/453); all remained in the study and were included in efficacy analyses. Through W72, 99% (486/489) of participants had HIV-1 RNA &lt; 50 copies/mL at their last study visit, including all with baseline NRTI-R or INSTI-R (Figure 2). Mean frequency of viral blips was 1% per timepoint, and blips were not associated with virologic failure. 112 participants (23%) had &lt; 95% adherence by pill count, 98% (110/112) of whom had HIV-1 RNA &lt; 50 copies/mL at last visit, including 14 of 14 (100%) with &lt; 80% adherence. No participant discontinued due to lack of efficacy or had treatment emergent resistance to study drugs.

Figure 2. Virologic suppression by preexisting resistance, viral blips, and adherence

Conclusion

Virologic suppression was maintained through W72 of B/F/TAF treatment, including those with preexisting resistance, viral blips, and suboptimal adherence. Continued HIV suppression and absence of treatment-emergent resistance demonstrate the efficacy of B/F/TAF in African Americans regardless of adherence or preexisting resistance to NNRTIs, PIs, or non-tenofovir NRTIs.

Disclosures

Kristen Andreatta, MSc, Gilead Sciences, Inc (Employee, Shareholder) Michelle L. D'Antoni, PhD, Gilead Sciences (Employee, Shareholder)Gilead Sciences, Inc (Employee, Shareholder) Silvia Chang, Masters, Gilead Sciences, Inc (Employee, Shareholder) Aiyappa Parvangada, MS Computational Biology, Gilead Sciences, Inc (Employee, Shareholder) Ross Martin, PhD, Gilead Sciences, Inc (Employee, Shareholder) Christiana Blair, MS, Gilead Sciences, Inc (Employee, Shareholder) Sean E. Collins, MD, MS, Gilead Sciences, Inc (Employee, Shareholder) Kirsten L. White, PhD, Gilead Sciences, Inc (Employee, Shareholder)

Global Burden of Disease from Major Air Pollution Sources (GBD MAPS): A Global Approach

Ambient fine particulate matter (particles <2.5 μm in aerodynamic diameter [PM2.5]) is the world's leading environmental health risk factor. Reducing the PM2.5 disease burden requires specific strategies that target dominant sources across multiple spatial scales. The Global Burden of Disease from Major Air Pollution Sources (GBD MAPS) project provides a contemporary and comprehensive evaluation of contributions to the ambient PM2.5 disease burden from source sectors and fuels across 21 regions, 204 countries, and 200 subnational areas. We first derived quantitative contributions from 24 emission sensitivity simulations using an updated global atmospheric chemistry-transport model, input with a newly developed detailed anthropogenic emissions dataset that includes emissions specific to source sector and fuels. These simulation results were integrated with newly available high-resolution satellite-derived PM2.5 exposure estimates and disease-specific concentration-response relationships consistent with the GBD project to quantify contributions of specific source sector and fuel to the ambient PM2.5 disease burden across all regions, countries, and subnational areas. To improve the transparency and reproducibility of this and future work, we publicly provided the global atmospheric chemistry-transport model source code, emissions dataset and emissions model source code, analysis scripts, and source sensitivity results, and further described the emissions dataset and source contribution results in two publications.

We found that nearly 1.05 million (95% uncertainty interval [UI]: 0.74-1.36 million) deaths worldwide (27.3% of the total mortality attributable to PM2.5) would be avoidable by eliminating fossil fuel combustion, with coal contributing over half of that burden. Residential (19.2%; 736,000 deaths [95% UI: 521,000-955,000]), industrial (11.7%; 448,000 deaths [95% UI: 318,000-582,000]), and energy (10.2%; 391,000 deaths [95% UI: 277,000-507,000]) sector emissions are among the dominant global sources Uncertainty in these estimates reflects those of the input datasets. Regions with the largest anthropogenic contributions generally have the highest numbers of attributable deaths, which clearly demonstrates the importance of reducing these emissions to realize reductions in global air pollution and its disease burden.

Referral pattern and co-management of keratoconus patients in primary eye care: A survey of three European countries

PURPOSE

To explore current primary care practices in keratoconus management in Portugal and compare with previous reported results in two European countries (the UK and Spain), with a special focus on interdisciplinary collaboration and referral practice patterns.

METHODS

An online survey adapted to European professional practice was distributed (via newsletters) by the Portuguese Optometrist Association to explore keratoconus patient management and referral practice patterns among Portuguese practitioners.

RESULTS

Responses of 119 optometrists were compared with previous reported of 464 eye-care practitioners (126 in the UK and 338 in Spain). Most respondents (79% in Portugal, 71% in the UK and 76% in Spain; p = 0.31) had < 5 new keratoconus patients each year. No accepted referral criterion was found (p < 0.01) because small number of the respondents (14%) in Portugal referred out at initial diagnosis (50% in the UK and Spain); 32% referred out when progression was detected (17% in the UK and 30% in Spain); and a minority (10% in Portugal, 9% in the UK, and 6% in Spain) referred out when visual acuity was affected. A majority of respondents (83%) in Portugal reported no co-management with ophthalmologists (60% in the UK and 73% in Spain; p < 0.01).

CONCLUSION

The results of this study suggest that it is necessary to encourage interdisciplinary collaboration between practitioners to improve referral of patients with suspected keratoconus to an ophthalmology specialist to change the course of this disease, to reduce keratoconus progression and visual acuity impairment and to minimize the impact of this disease on patients' quality of life.

External Waveguide Magnetic Resonance Imaging for lower limbs at 3 T

INTRODUCTION

We report a method based on the travelling-wave MRI approach, in order to acquire images of human lower limbs with an external waveguide at 3 T.

METHOD

We use a parallel-plate waveguide and an RF surface coil for reception, while a whole-body birdcage is used for transmission. The waveguide and the surface coil are located right outside the magnet, in the MR conditional devices zone. We ran numerical simulations to investigate the B₁ field generated by the surface coil located at one of the waveguides, as well as a saline-solution phantom positioned on the opposite side (150 cm away) inside the magnet.

RESULTS

We obtained phantom images by varying the distance between the coil and the phantom, in order to investigate the signal-to-noise ratio and to validate our numerical simulations. Lower limb images of a healthy volunteer were also acquired, demonstrating the viability of this approach. Standard pulse sequences were used and no physical modifications were made to the MR imager.

CONCLUSIONS

These numerical and experimental results show that travelling-wave MRI can produce high-quality images with only a simple waveguide and an RF coil located outside the magnet. This can be particularly favorable when acquiring images of lower limbs requiring a larger field of view.

Measurement and prevalence of adult physical activity levels in Arab countries

OBJECTIVES

This study aims to examine the reported prevalence of sufficient physical activity among adults in Arab countries and to determine the use of validated instruments for assessing physical activity.

STUDY DESIGN

This is a systematic literature review.

METHODS

This review follows recommendations outlined in the Meta-Analysis of Observational Studies in Epidemiology guidelines. The protocol for this study was preregistered with PROSPERO. Cross-sectional, cohort and intervention studies with a minimum of 300 adults aged ≥18 years assessing physical activity using a questionnaire or other self-report measure in the Arabic language were identified from seven electronic databases (MEDLINE, Embase, Cochrane Database of Systematic Reviews, CINAHL, PsycINFO, SPORTDiscu and PubMed). Databases were searched from 1st January 2008 to 17th September 2018. Descriptive analysis was performed using frequency and percentages. The prevalence of physical activity was calculated as the average prevalence for the reported percentages from the studies with similar tools.

RESULTS

Fifty studies involving 298,242 participants were included in this review. The mean (range) sample size was 5964.8.1 (323-197,681). Data were collected from participants in 16 of the 22 Arab countries. Great variation exists across the studies in determining whether adults were sufficiently active or not. Twenty studies reported usable data from the Global Physical Activity Questionnaire and the International Physical Activity Questionnaire (moderate & high categories). In these studies, prevalence of physical activity ranged from 34.2 to 96.9%. It was not possible to compare the other studies owing to variation in instruments used to assess physical activity and in the case definition used for 'physically active'.

CONCLUSIONS

This study highlights the need for wider reporting of physical activity and the adoption of valid and reliable instruments to support the development of evidence-informed policy and programmes at both country and regional level. International tools need to be correctly validated, or context-specific tools must be developed to accurately measure physical activity.

Three-year study of pre-existing drug resistance substitutions and efficacy of bictegravir/emtricitabine/tenofovir alafenamide in HIV-1 treatment-naive participants

OBJECTIVES

Two Phase 3, randomized, double-blind, active-controlled studies of initial HIV-1 treatment demonstrated that bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) was non-inferior to dolutegravir/abacavir/lamivudine (DTG/ABC/3TC; Study 1489) or to DTG+F/TAF (Study 1490) through 144 weeks. In both studies, there was no emergent resistance to study drugs. Here, the 3 year resistance analysis and impact of baseline resistance substitutions on treatment response are described.

METHODS

Population sequencing of HIV-1 protease and reverse transcriptase (RT) was performed at screening. Retrospective baseline next generation sequencing of protease, RT and integrase (IN) was analysed at a ≥ 15% cutoff. Resistance analyses were performed on participants with confirmed viral rebound of HIV-1 RNA ≥200 copies/mL through Week 144 or last visit who did not resuppress to <50 copies/mL while on study drug.

RESULTS

Transmitted primary drug resistance substitutions were present in the following proportions of participants: integrase strand transfer inhibitor (INSTI) resistance (-R) in 1.3% (17/1270) of participants; NRTI-R in 2.7% (35/1274); NNRTI-R in 14.1% (179/1274); and PI-R in 3.5% (44/1274). These pre-existing resistance substitutions not associated with study drug did not affect treatment outcomes. One participant in the B/F/TAF group had pre-existing bictegravir and dolutegravir resistance substitutions (Q148H+G140S in integrase) at baseline and suppressed and maintained HIV-1 RNA <50 copies/mL through Week 144. In total, 21 participants qualified for resistance testing [1.3% (8/634) B/F/TAF; 1.9% (6/315) DTG/ABC/3TC; 2.2% (7/325) DTG+F/TAF]; none had emergent resistance to study drugs.

CONCLUSIONS

Treatment with B/F/TAF, DTG/ABC/3TC, or DTG+F/TAF achieved high, durable rates of virological suppression in HIV-1 treatment-naive participants. The presence of pre-existing resistance substitutions did not affect treatment outcomes, and there was no treatment-emergent resistance.

POS1044 EFFECT OF SECUKINUMAB VERSUS ADALIMUMAB ON ACR CORE COMPONENTS AND HEALTH-RELATED QUALITY OF LIFE IN PATIENTS WITH PSORIATIC ARTHRITIS: RESULTS FROM THE EXCEED STUDY

Background:

EXCEED (NCT02745080) was the first fully blinded head-to-head trial to evaluate the efficacy and safety of secukinumab (SEC) versus (vs) adalimumab (ADA) monotherapy in patients with active psoriatic arthritis (PsA) with a primary endpoint of American College of Rheumatology (ACR) 20 at Week 52. Although SEC narrowly missed statistical significance for superiority vs ADA, numerically higher response for other musculoskeletal endpoints and composite indices were observed with SEC.1

Objectives:

To explore the effect of SEC and ADA on ACR core components, function and Health-related Quality of Life (HRQoL) outcomes.

Methods:

Patients were randomised 1:1 to receive SEC 300 mg (N=426) subcutaneous (s.c.) at baseline, Week 1-4, followed by every 4 weeks until Week 48 or ADA 40 mg (N=427) s.c. at baseline followed by same dosing every 2 weeks until Week 50. The primary, key secondary and some exploratory endpoints at Week 52 were previously reported.1 A supportive analysis for ACR50 response using logistic regression model and trimmed means model for Health Assessment Questionnaire-Disability Index (HAQ-DI) with gender and smoking status as factors was performed to adjust for imbalances in baseline characteristics. An exploratory analysis of ACR core components with SEC vs ADA at Week 52 was conducted using a mixed-effects repeated measures model that included tender and swollen joint counts, patient and physician global assessment, PsA pain (VAS) and erythrocyte sedimentation rate. HRQoL variables were also exploratory and assessed based on Short Form Health Survey Physical/Mental Component Summary (SF-36 PCS/MCS) scores and Dermatology Life Quality Index (DLQI).

Results:

The demographic and baseline disease characteristics were comparable across treatment groups, except for an imbalance in sex (females: 51.2% vs 46.4%) and smoking status (yes: 21.8% vs 17.8%) in SEC and ADA group, respectively. At Week 52, ACR50 responses were 49.0% and 44.8% (P=0.0929) and HAQ-DI mean change from baseline were −0.69 and −0.58 (P=0.0314) in SEC and ADA treatment groups, respectively after adjusting for gender and smoking status. No major difference across ACR core components was observed in both treatment groups at Week 52 (Table 1). At Week 52, SEC presented similar improvement in SF-36 PCS/MCS score and numerically higher improvement in DLQI compared to ADA (Figure 1).

Conclusion:

Secukinumab provided similar improvements in ACR core components and SF-36 based quality of life at Week 52 with adalimumab. Greater improvement in HAQ-DI response and DLQI was demonstrated with secukinumab compared to adalimumab.

References:

[1]McInnes IB, et al. Lancet. 2020; 395:1496–505.

Table 1.

ACR Core Components at Week 52

VariablesSecukinumab 300 mg(N=426)Adalimumab 40 mg(N=427)P-valueBL, mean ± SELSM change from BL ± SEBL, mean ± SELSM change from BL ± SETender joint score(based on 78 joints)19.4 ± 13.86−14.27 ± 0.4420.6 ± 14.81−13.90 ± 0.450.5549Swollen joint score(based on 76 joints)9.7 ± 7.30−8.41 ± 0.1910.2 ± 7.86−8.06 ± 0.200.1962Patients global assessment64.0 ± 19.67−33.81 ± 1.1461.9 ± 20.75−31.61 ± 1.190.1825Physicians global assessment60.0 ± 17.12−46.24 ± 0.8061.4 ± 15.92−43.63 ± 0.840.0243Psoriatic arthritis pain (VAS)58.6 ± 23.49−30.21 ± 1.1857.9 ± 22.42−29.44 ± 1.230.6500Erythrocyte sedimentation rate (mm/h)23.8 ± 18.93−9.63 ± 0.6223.9 ± 17.99−9.28 ± 0.640.7029

LS mean and nominal P-values are from a mixed-effects repeated measures model with treatment group, analysis visit as factors, weight and BL score as covariates, and by treatment and BL score as interaction terms, unstructured covariance structure. ACR, American College of Rheumatology; BL, baseline; LSM, least squares mean; N, total number of randomised patients; SE, standard error; VAS, visual analogue scale

Figure 1.

HRQoL Analysis at Week 52

Disclosure of Interests:

Philippe Goupille Speakers bureau: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Eli Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Consultant of: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Eli Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Grant/research support from: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Eli Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Frank Behrens Paid instructor for: Eli Lilly, Consultant of: Pfizer, AbbVie, Sanofi, Eli Lilly, Novartis, Genzyme, Boehringer Ingelheim, Janssen, MSD, Celgene, Roche and Chugai, Grant/research support from: Pfizer, Janssen, Chugai, Celgene and Roche, Laura C Coates Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Biogen, BMS, Celgene, Domain, Eli Lilly, Gilead, GSK, Janssen, Medac, Novartis, Pfizer, Serac and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Jordi Gratacos-Masmitja Speakers bureau: AbbVie, Amgen, BMS, Celgene, Janssen, Eli Lilly, Novartis and Pfizer, Consultant of: AbbVie, Amgen, BMS, Celgene, Janssen, Eli Lilly, Novartis and Pfizer, Grant/research support from: AbbVie, Amgen, BMS, Celgene, Janssen, Eli Lilly, Novartis and Pfizer, Philip J Mease Speakers bureau: AbbVie, Amgen, Genentech, Janssen, Eli Lilly, Merck, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Boehringer Ingelheim, Galapagos, Celgene, Genentech, Gilead, Janssen, Eli Lilly, Novartis, Pfizer, SUN Pharma, and UCB, Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Galapagos, Genentech, Gilead, Janssen, Eli Lilly, Merck, Novartis, Pfizer, SUN Pharma, and UCB, Dafna D Gladman Consultant of: Amgen, AbbVie, BMS, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Novartis, Pfizer and UCB, Grant/research support from: Amgen, AbbVie, Celgene, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Peter Nash Speakers bureau: Novartis, Abbvie, Roche, Pfizer, BMS, Janssen, Celgene, UCB, Eli Lilly, MSD, Sanofi, Gilead, Consultant of: Novartis, Abbvie, Roche, Pfizer, BMS, Janssen, Celgene, UCB, Eli Lilly, MSD, Sanofi, Gilead, Grant/research support from: Novartis, Abbvie, Roche, Pfizer, BMS, Janssen, Celgene, UCB, Eli Lilly, MSD, Sanofi, Gilead, Arthur Kavanaugh Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, and UCB, Ruvie Martin Shareholder of: Novartis, Employee of: Novartis, Weibin Bao Shareholder of: Novartis, Employee of: Novartis, Corine Gaillez Shareholder of: Novartis and BMS, Employee of: Novartis, Iain McInnes Speakers bureau: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Janssen, Eli Lilly, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Janssen, Eli Lilly, Novartis, Pfizer, and UCB.

The role of marshall bundle epicardial connections in atrial tachycardias after atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial tachycardias (ATs) are often seen in the context of AF ablation.

Objectives

We evaluated the role of the Marshall bundle (MB) network in left atrial (LA) ATs using high-density high-spatial resolution 3D mapping.

Methods

199 post-AF ablation LA tachycardias were mapped in 140 consecutive patients (112 (80%) males, mean age: 61.8 years); 133 (66.8%) were macro-reentrant and 66 (33.2%) were scar-related re-entry. MB-dependent perimitral AT (PMAT) was diagnosed where the difference between the post pacing interval and the tachycardia cycle length (PPI-TCL) was &lt;20ms in parts of the expected MB-dependent perimitral circuit (within the VOM, the ridge between the left pulmonary veins and LA appendage (LAA), the anterior LA and between 6- and 11-o’clock of the mitral annulus) and the PPI-TCL was &gt;20ms in areas bypassed by the VOM (the distal coronary sinus (CS), the posterior LA and the mitral isthmus). MB-related re-entry was diagnosed by PPI-TCL &lt;20ms at the left lateral ridge, posterior base of LAA, inferolateral LA or VOM ostium; and PPI-TCL &gt;20ms in the septal annulus. Typically, in MB-dependent localized re-entry, the earliest activation was found along the MB-LA endocardial connection or MB-CS epicardial connection. 

Results

The MB network was found to participate in 60 (30.2%) re-entrant ATs, 31 PMATs and 29 localized re-entries. High-frequency multiphasic fragmented electrograms with long duration were often recorded endocardially or epicardially at the MB-LA or MB-CS connections. The amplitude and duration of these signals were 0.5 ± 0.79 mV and 65 ± 40 ms for MB-PMATs and 0.26 ± 0.28mV and 122 ± 67 ms for MB-localized re-entries. Unipolar EGMs at the site of endocardial-epicardial breakthrough had a rS pattern in all MB-related ATs. Of 60 MB-related ATs, 49 (81.6%) terminated with RF ablation, 44 (73.3%) at the MB-LA junction and 5 (8.3%) at the MB-CS junction, while 9 (15%) terminated after 2.5-5 cc of alcohol infusion inside the vein of Marshall (VOM). Of the 31 MB-related macroreentrant ATs, 17 (54.8%) terminated at the MB-LA junction, 5 (16.1%) at the MB-CS junction and 7 (22.6%) with alcohol infusion inside the VOM. Two macroreentries (6.5%) using the MB did not terminate with RF energy either endocardially at the MB-LA junction or epicardially at the MB-CS junction, and we were unable to identify or cannulate the VOM for ethanol infusion. Of the 29 localized re-entrant ATs using the MB, 27 (93.1%) terminated at the MB-LA junction, none terminated at the MB-CS junction and 2 (6.9%) terminated after alcohol infusion. After a mean follow up of 12 months, only 4 patients (6.7%) had AT recurrence.

Conclusions

MB re-entrant ATs accounted for up to 29% of the left ATs after AF ablation. Ablation of the MB-LA or CS-MB connections or alcohol infusion inside the VOM is required to treat these arrhythmias. Abstract Figure.

Simulating HIV Breakthrough and Resistance Development During Variable Adherence to Antiretroviral Treatment

BACKGROUND

Barriers to lifelong HIV-1 suppression by antiretrovirals include poor adherence and drug resistance; regimens with higher tolerance to missed doses (forgiveness) would be beneficial to patients. To model short-term nonadherence, in vitro experiments monitoring viral breakthrough (VB) and resistance development were conducted.

METHODS

HIV breakthrough experiments simulated drug exposures at full adherence or suboptimal adherence to bictegravir+emtricitabine+tenofovir alafenamide (BIC+FTC+TAF) or dolutegravir + lamivudine (DTG+3TC). MT-2 cells were infected with wild-type or low frequency M184V HIV-1, exposed to drug combinations, monitored for VB, and rebound virus was deep sequenced. Drug concentrations were determined using human plasma-free adjusted clinical trough concentrations (Cmin), at simulated Cmin after missing 1 to 3 consecutive doses (Cmin - 1 or Cmin - 2, and Cmin - 3) based on drug or active metabolite half-lives.

RESULTS

Cultures infected with wild-type or low frequency M184V HIV-1 showed no VB with BIC+FTC+TAF at drug concentrations corresponding to Cmin, Cmin - 1, or Cmin - 2 but breakthrough did occur in 26 of 36 cultures at Cmin - 3, where the M184V variant emerged in one culture. Experiments using DTG + 3TC prevented most breakthrough at Cmin concentrations (9/60 had breakthrough) but showed more breakthroughs as drug concentrations decreased (up to 36/36) and variants associated with resistance to both drugs emerged in some cases.

CONCLUSIONS

These in vitro VB results suggest that the high potency, long half-lives, and antiviral synergy provided by the BIC/FTC/TAF triple therapy regimen may protect from viral rebound and resistance development after short-term lapses in drug adherence.

Generation of an HBV core phenotyping assay for evaluating HBV capsid compounds

Hepatitis B virus (HBV) capsids are assembled from HBV core protein and assembly is a critical step in the propagation of the virus. Due to its multiple functions in the viral life cycle, core is an attractive target for new antiviral therapies. For HBV capsid assembly modulators (CAMs), several resistance mutants have been identified, both from the clinic and in vitro. However, currently there is no convenient in vitro assay to monitor resistance to CAMs in the clinic. Here, we developed a facile, cassette-based phenotyping assay to assess the antiviral activity of CAMs on a panel of clinical isolates. Using this system, the core genes from 13 patients infected with HBV genotypes A-H were expressed as chimeric virus and tested for sensitivity to CAMs. No substantial differences in antiviral activity were observed across genotypes due to the conservation of the drug binding pocket. In addition, we tested a panel of constructs encoding 13 single amino acid polymorphs in the CAM binding site, including some polymorphs with previously-described resistance to CAMs. Overall, 11 of 13 constructs replicated in vitro, 6 constructs showed reduced susceptibility to CAMs. The 11 polymorphs which could replicate in vitro remained sensitive to the nucleotide analog tenofovir alafenamide (TAF), indicating that there is no cross-resistance.

Genetic conservation of SARS-CoV-2 RNA replication complex in globally circulating isolates and recently emerged variants from humans and minks suggests minimal pre-existing resistance to remdesivir

Remdesivir (RDV) exhibits potent antiviral activity against SARS-CoV-2 and is currently the only drug approved for the treatment of COVID-19. However, little is currently known about the potential for pre-existing resistance to RDV and the possibility of SARS-CoV-2 genetic diversification that might impact RDV efficacy as the virus continue to spread globally. In this study, >90,000 SARS-CoV-2 sequences from globally circulating clinical isolates, including sequences from recently emerged United Kingdom and South Africa variants, and >300 from mink isolates were analyzed for genetic diversity in the RNA replication complex (nsp7, nsp8, nsp10, nsp12, nsp13, and nsp14) with a focus on the RNA-dependent RNA polymerase (nsp12), the molecular target of RDV. Overall, low genetic variation was observed with only 12 amino acid substitutions present in the entire RNA replication complex in ≥0.5% of analyzed sequences with the highest overall frequency (82.2%) observed for nsp12 P323L that consistently increased over time. Low sequence variation in the RNA replication complex was also observed among the mink isolates. Importantly, the coronavirus Nsp12 mutations previously selected in vitro in the presence of RDV were identified in only 2 isolates (0.002%) within all the analyzed sequences. In addition, among the sequence variants observed in ≥0.5% clinical isolates, including P323L, none were located near the established polymerase active site or sites critical for the RDV mechanism of inhibition. In summary, the low diversity and high genetic stability of the RNA replication complex observed over time and in the recently emerged SARS-CoV-2 variants suggests a minimal global risk of pre-existing SARS-CoV-2 resistance to RDV.

Remote RF excitation for small-bore MR imager at 15.2 T

We report a method for remote excitation of the RF signal for preclinical-equivalent ultra high field Magnetic Resonance Imaging (MRI). A parallel-plate waveguide together with a bio-inspired surface coil were used to perform remote excitation experiments to acquire images with a small-bore MR imager at 15.2 T. The imager bore size limits the RF coil transmitter dimensions, so the Gielis super-formula was used to design an RF coil with small dimensions. Electromagnetic simulations of the principal mode were run to study the waveguide filled with air and loaded with a saline solution-filled tube. Radiation patterns were also computed in a semi-anechoic chamber for the same scenarios as above. A saline solution-filled spherical phantom and a formaldehyde-fixed mouse phantom were used to acquire images. Radiation patterns showed an omnidirectional distribution with no side lobes, and a very smooth behaviour with almost no loss of information in the saline solution-filled tube and without. The theoretical wave impedance was calculated and compared with simulated results showing an excellent correspondence. Spherical phantom image data and simulation results of B₁ were contrasted and showed an important correlation. Ex vivo mouse images were of high quality and exhibited clear delineation of anatomical structures. These imaging results are in very good agreement with the simulations. Numerical, theoretical and experimental results validate this approach, using a bio-inspired surface coil with a simple waveguide for preclinical small-bore MRI at ultra high field.

Characterization of Hepatitis B virus polymerase mutations A194T and CYEI and tenofovir disoproxil fumarate or tenofovir alafenamide resistance

Both the A194T and a quadruple mutation CYEI (S106C, H126Y, D134E and L269I) in hepatitis B virus (HBV) polymerase reverse transcriptase domain (pol/RT) are suggested to be associated with treatment failure with tenofovir disoproxil fumarate (TDF). To further evaluate this assertion, the prevalence of these mutations at baseline as well as their development and/or loss during TDF and tenofovir alafenamide (TAF) treatment was analysed in 3886 patients enrolled in Gilead HBV clinical studies. In total, six out of 3886 (0.2%) patients carried the rtA194T mutation, while only 1 patient carried a triple CYE and 2 patients carried a quadruple CYEI mutation at baseline. All the patients harbouring rtA194T or CYE/CYEI at baseline achieved viral suppression by week 96 after TDF or TAF treatment. No patients developed an rtA194T mutation or > 1 substitution of CYEI, and the number of patients losing any substitutions of CYEI (n = 17) was similar to the number who developed a single substitution of CYEI (n = 32) during treatment. Phenotypic evaluation of the site-directed mutant (SDM) panel containing these mutations with or without other resistance mutations did not demonstrate a significant shift in TFV and TAF potency in vitro. No evidence of rtA194T and CYEI conferring resistance to TDF or TAF was observed based on the treatment responses to TDF or TAF in patients with mutations at baseline, the lack of selection of mutations after starting TDF or TAF treatment and no change in susceptibility to TFV or TAF in vitro.

633. Bictegravir/Emtricitabine/Tenofovir Alafenamide (B/F/TAF) Efficacy in Participants with Pre-Existing Primary Integrase Inhibitor Resistance Through 48 Weeks of Phase 3 Clinical Trials

Background

Pre-existing drug resistance can affect the efficacy of antiretroviral therapy. Studies in treatment-naïve and virologically suppressed participants have demonstrated safety and efficacy of B/F/TAF, including in patients with M184V/I mutations. In this pooled analysis, we investigated virologic outcomes after 48 weeks of B/F/TAF treatment in individuals with pre-existing integrase strand transfer inhibitor resistance (INSTI-R).

Methods

Although INSTI-R was prohibited per study entry criteria, pre-existing INSTI-R (T66A/I/K, E92G/Q, F121Y, Y143C/H/R, S147G, Q148H/K/R, N155H/S, R263K) was evaluated in participants from studies 1489, 1490, 1844, 1878, 4030. INSTI-R was assessed by historical genotypes and/or retrospective deepType HIV assay (Seq-IT, Germany), GenoSure IN, GenoSure Archive (Monogram Biosciences). Virologic outcomes were defined by last on-treatment observation carried forward (LOCF) method.

Results

Pre-existing primary INSTI-R substitutions were detected in 20/1907 participants (1.0%) after enrolment. Of the 20, 75% were male, 30% white, and 85% had HIV-1 subtype B, baseline median CD4 counts of 594 (IQR 517, 700), and median age of 52 (43, 59) years. One participant was treatment-naïve with a baseline viral load of 30,000 copies/ml and had Q148H (+ G140S on plasma RNA genotype) and was sensitive to bictegravir (< 2.5-fold change). The other 19 participants were virologically suppressed and had E92G (n=3), Y143C (n=2), Y143H (n=4), S147G (n=2), N155S (n=1), Q148H (n=3), Q148K (n=1), Q148R (n=1), or R263K (n=2) INSTI-R mutations by DNA genotype. The treatment-naïve individual was suppressed by Week 4 and maintained viral loads of < 50 copies/mL through Week 48. All suppressed participants had HIV RNA < 50 copies/mL throughout Week 48. All study participants had virologic success by LOCF (< 50 copies/mL) at Week 48.

Conclusion

Participants with primary INSTI-R substitutions had or maintained virologic suppression through 48 weeks of B/F/TAF treatment. Consistent with the potent in vitro activity of bictegravir against many INSTI-R mutations, these virologic outcomes suggest that B/F/TAF may have potential as a treatment option for some patients with pre-existing INSTI-R, if confirmed by further studies.

Disclosures

Michelle L. D’Antoni, PhD, Gilead Sciences (Employee, Shareholder) Kristen Andreatta, MSc, Gilead Sciences (Employee, Shareholder) Rima K. Acosta, BS, Gilead Sciences, Inc. (Employee, Shareholder) Silvia Chang, Masters, Gilead Sciences (Employee, Shareholder) Ross Martin, PhD, Gilead Sciences (Employee, Shareholder) Kirsten L. White, PhD, Gilead Sciences, Inc. (Employee, Shareholder)

Developing a sensitive HBV genotyping assay for HBV DNA suppressed patients using both DNA and RNA sequencing

Hepatitis B virus (HBV) genotypes impact treatment outcomes and disease progression. The current genotyping methods have limitations in patients with low HBV viral load. In this study, a more sensitive assay has been developed for determining the HBV genotype in HBV DNA suppressed patients. Fifty-five serum samples from 55 chronic hepatitis B patients (HBeAg-, n = 20; HBeAg+, n = 35) across genotypes A to H with long-term nucleos(t)ide analogs (NAs) treatment were collected. All samples had HBV DNA less than 29 IU/mL. Total nucleic acid (viral DNA and RNA) was extracted and a 341 bp amplicon located at HBV S gene overlapping with reverse transcriptase domain of polymerase (pol/RT) was amplified via real time (RT)-nested polymerase chain reaction (PCR) followed by population sequencing. HBV genotype was determined by phylogenetic analysis. The assay successfully amplified HBV S/RT gene from 53 of 55 (96.4%) patient serum samples. Phylogenetic analysis demonstrated that the genotypes of all the 53 PCR positive samples matched the historical genotypes as determined by INNO-LiPA or RT sequence from the corresponding baseline samples. This assay was able to accurately determine HBV genotype irrespective of baseline genotype, HBeAg status, or duration of viral suppression. The ability to determine genotype in virally suppressed patients may facilitate the evaluation of novel treatment agents for HBV in this patient population.

Artificial intelligence-guided image acquisition on patients with implanted electrophysiological devices: results from a pivotal prospective multi-center clinical trial

Background

A novel, recently FDA-authorized software uses deep learning (DL) to provide prescriptive transthoracic echocardiography (TTE) guidance, allowing novices to acquire standard TTE views. The DL model was trained by &gt;5,000,000 observations of the impact of probe motion on image orientation/quality. This study evaluated whether novice-acquired TTE images guided by this software were of diagnostic quality in patients with and without implanted electrophysiological (EP) devices, focusing on RV size and function, which were thought to be sensitive to EP devices. Some aspects of the study have previously been presented.

Methods

240 patients (61±16 years old, 58% male, 33% BMI &gt;30 kg/m2, 91% with cardiac pathology) were recruited. 8 nurses without echo experience each acquired 10 view TTEs in 30 patients guided by the software. 235 of the patients were also scanned by a trained sonographer without assistance from the software. 5 Level 3 echocardiographers independently assessed the diagnostic quality of the TTEs acquired by the nurses and sonographers to evaluate the effect of EP devices on DL software performance.

Results

Nurses using the AI-guided acquisition software acquired TTEs of sufficient quality to make qualitative assessments of right ventricular (RV) size and function in greater than 80% of cases for patients with and without implanted EP devices (Table). There was no significant difference between nurse- and sonographer-acquired scans.

Conclusion

These results indicate that new DL software can guide novices to obtain TTEs that enable qualitative assessment of RV size even in the presence of implanted EP devices. The results of the comparison to sonographer-acquired exams indicate the software performance is robust to presence of pacemaker/ICD leads visible in the images (Figure).

Nurse-acquired TTE with visible ICD lead

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Caption Health, Inc.