Real-world application of tumor mutational burden-high (TMB-high) and microsatellite instability (MSI) confirms their utility as immunotherapy biomarkers

Introduction

Microsatellite instability (MSI) testing and tumor mutational burden (TMB) are genomic biomarkers used to identify patients who are likely to benefit from immune checkpoint inhibitors. Pembrolizumab was recently approved by the Food and Drug Administration for use in TMB-high (TMB-H) tumors, regardless of histology, based on KEYNOTE-158. The primary objective of this retrospective study was real-world applicability and use of immunotherapy in TMB/MSI-high patients to lend credence to and refine this biomarker.

Methods

Charts of patients with advanced solid tumors who had MSI/TMB status determined by next generation sequencing (NGS) (FoundationOne CDx) were reviewed. Demographics, diagnosis, treatment history, and overall response rate (ORR) were abstracted. Progression-free survival (PFS) was determined from Kaplan–Meier curves. PFS1 (chemotherapy PFS) and PFS2 (immunotherapy PFS) were determined for patients who received immunotherapy after progressing on chemotherapy. The median PFS2/PFS1 ratio was recorded.

Results

MSI-high or TMB-H [≥20 mutations per megabase (mut/MB)] was detected in 157 adults with a total of 27 distinct tumor histologies. Median turnaround time for NGS was 73 days. ORR for most recent chemotherapy was 34.4%. ORR for immunotherapy was 55.9%. Median PFS for patients who received chemotherapy versus immunotherapy was 6.75 months (95% confidence interval, 3.9-10.9 months) and 24.2 months (95% confidence interval, 9.6 months to not reached), respectively (P = 0.042). Median PFS2/PFS1 ratio was 4.7 in favor of immunotherapy.

Conclusion

This real-world study reinforces the use of TMB as a predictive biomarker. Barriers exist to the timely implementation of NGS-based biomarkers and more data are needed to raise awareness about the clinical utility of TMB. Clinicians should consider treating TMB-H patients with immunotherapy regardless of their histology.

•

This retrospective study examined the real-world use of immune checkpoint inhibitors (ICIs) in TMB/MSI-high patients with a diverse set of cancer types.

•

TMB is an emerging tumor-agnostic biomarker for response to treatment with ICIs that may expand personalized cancer care.

•

ICIs remain underutilized as a first-line therapy for TMB/MSI-H patients without specific histologic approval for ICIs.

•

The PFS2 to PFS1 ratio was 4.7, favoring immunotherapy over chemotherapy even as a second-line therapy.

•

Our study reinforces the real-world evidence that TMB is a valid surrogate marker for MSI and can predict response to ICIs.

[SARS-CoV-2 infections in cats, dogs, and other animal species: Findings on infection and data from Switzerland]

INTRODUCTION

The pandemic with the novel coronavirus (SARS-CoV-2) has led to infections and deaths worldwide. Apart from humans, certain animal species are susceptible to the viral infection. Spillover between humans and animals is favored by close contact; thus, surveillance of animals is an important component to fight the pandemic from a One Health perspective. The Clinical Laboratory of the Vetsuisse Faculty Zurich has been investigating SARS-CoV-2 infections in animals since the beginning of the pandemic. In November 2020, the first SARS-CoV-2 positive Swiss cat was reported to the World Organisation for Animal Health (OIE-WAHIS). The cat showed respiratory signs and lived in a COVID-19 affected household. By now, over 500 natural SARS-CoV-2 infections have been recorded in animals worldwide. A prevalence study on SARS-CoV-2 infections in dogs and cats was carried out together with clinics from Germany and Italy during the first wave of the pandemic (March-July 2020). Among the tested 1137 animals, only one cat and one dog were positive. The prevalence of infection in dogs and cats presented to veterinary clinics was low, even in pandemic hotspot regions. However, recent studies that focused on animals in COVID-19 households found a higher prevalence of infection. A study is currently underway that specifically collects samples from pets from Swiss COVID-19 affected household and collects data on human-animal interaction.

597 Counting on You to do The Count: An Unusual Case Report of a Delayed and Missed Gossypiboma Secondary to Swiss Cheese Model Failings

Introduction

Gossypiboma is a term describing a retained surgical swab which is a serious complication following any surgical intervention. The incidence of these cases is wholly under reported, partly due to medicolegal aspects, but also due to the misnomer of diagnosis. In this case, we discuss the multifactorial deficiencies which led to a significant morbidity in a patient who had remained asymptomatic for nine years since index surgery.

Case Presentation

A 40-year-old woman presented to the emergency department febrile with a one week history of abdominal pain, on a background of a one year history of chronic pain. The patient’s surgical history demonstrated an ovarian fibroid excision and a subtotal hysterectomy nine and six years ago, respectively. It was later noted the chronic abdominal pain had been previously investigated with positive findings on imaging and biopsy, however, she was lost to follow up. A year later, she presented with an acute abdomen and operative findings of a large abscess cavity, containing a retained swab, with small bowel fistulation were noted.

Conclusions

This reiterates the importance of surgical safety checklists, and often despite this there are many factors that can eventually lead to complete alignment of the holes in the Swiss Cheese leading to unfavourable outcomes. It is imperative to remain hypervigilant during checkpoints, particularly in emergencies where the unpredictability of the operation leads to human error. Gossypiboma remains a serious cause for morbidity and mortality, thus the potential for modified safety checklists or alternative methods for surgical counts.

240 Aetiology and Outcomes of Head and Neck Free Flaps in Patients Aged ≥ 65 Years: The Cambridge Experience

Introduction

Elderly patients often present to the Head & Neck Plastic Surgery department with complex reconstructive needs, for which free flaps are the gold-standard management. In order to provide appropriate, patient-centred care, it is imperative to understand how increasing age and related factors affect long-term free flap outcomes.

Method

The authors carried out a retrospective review of all patients 65+ years who underwent free flap surgery at Addenbrooke’s Hospital from 2008-2019. Patient, operative, and flap characteristics, and outcomes, were analysed using Excel and RStudio.

Results

163 patients were identified (54F, 109M). The majority were ALT (n = 74), radial forearm (n = 35), and fibula flaps (n = 23).

Of pre-operative comorbidities, only neurological comorbidities (n = 16), were significantly associated with long-term flap failure (p = 0.016). There was no significant association between number of comorbidities and flap outcome. There was no association between age group and length of stay.

Flap site complications, and particularly venous complications, were significantly associated with later failure (p = 0.001). No other complications were statistically associated with flap failure.

Conclusions

The high success rate supports the use of free flaps in the 65+ population. This data supports a case-by-case approach to assessing fitness for free flap surgery rather than excluding patients on the basis of age or specific comorbidities.

ACE inhibitors, angiotensin receptor blockers and endothelial injury in COVID-19

BACKGROUND

COVID-19 is caused by the coronavirus SARS-CoV-2, which uses angiotensin-converting enzyme 2 (ACE-2) as a receptor for cellular entry. It is theorized that ACE inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) may increase vulnerability to SARS-CoV-2 by upregulating ACE-2 expression, but ACE-I/ARB discontinuation is associated with clinical deterioration.

OBJECTIVE

To determine whether ACE-I and ARB use is associated with acute kidney injury (AKI), macrovascular thrombosis and in-hospital mortality.

METHODS

A retrospective, single-centre study of 558 hospital inpatients with confirmed COVID-19 admitted from 1 March to 30 April 2020, followed up until 24 May 2020. AKI and macrovascular thrombosis were primary end-points, and in-hospital mortality was a secondary end-point.

RESULTS

AKI occurred in 126 (23.1%) patients, 34 (6.1%) developed macrovascular thrombi, and 200 (35.9%) died. Overlap propensity score-weighted analysis showed no significant effect of ACE-I/ARB use on the risk of occurrence of the specified end-points. On exploratory analysis, severe chronic kidney disease (CKD) increases odds of macrovascular thrombi (OR: 8.237, 95% CI: 1.689-40.181, P = 0.009). The risk of AKI increased with advancing age (OR: 1.028, 95% CI: 1.011-1.044, P = 0.001) and diabetes (OR: 1.675, 95% CI: 1.065-2.633, P = 0.025). Immunosuppression was associated with lower risk of AKI (OR: 0.160, 95% CI: 0.029-0.886, P = 0.036). Advancing age, dependence on care, male gender and eGFR < 60 mL min^-1 /1.73 m² increased odds of in-hospital mortality.

CONCLUSION

We did not identify an association between ACE-I/ARB use and AKI, macrovascular thrombi or mortality. This supports the recommendations of the European and American Societies of Cardiology that ACE-Is and ARBs should not be discontinued during the COVID-19 pandemic.

THU0271 PERFORMANCE OF THE EULAR/ACR 2019 CLASSIFICATION CRITERIA FOR SYSTEMIC LUPUS ERYTHEMATOSUS IN EARLY DISEASE, ACROSS SEXES AND ETHNICITIES

Background:

EULAR/ACR 2019 SLE Classification Criteria were validated in an international cohort.

Objectives:

To evaluate performance characteristics of SLE classification systems in sex, race/ethnicity, and disease duration subsets.

Methods:

Sensitivity and specificity of the EULAR/ACR 2019, SLICC 2012 and ACR 1982/1997 criteria were evaluated in the validation cohort.

Results:

The cohort consisted of female (n=1098), male (n=172), Asian (n=118), Black (n=68), Hispanic (n=124) and White (n=941) patients; and patients with an SLE duration of 1-3 years (n=196), 3-5 years (n=157), and ≥5 years (n=879). Among patients with 1-3 years disease duration, the EULAR/ACR criteria had better sensitivity than the ACR criteria (97% (95%CI 92-99%) vs 81% (95%CI 72-88%). The new criteria performed well in men (sensitivity 93%, specificity 96%) and women (sensitivity 97%, specificity 94%). The new criteria had better sensitivity than the ACR criteria in White (95% vs 83%), Hispanic (100% vs 86%) and Asian patients (97% vs 77%).

Conclusion:

The EULAR/ACR 2019 criteria perform well in patients with early disease, and across sexes and ethnicities.

Disclosure of Interests:

Sindhu Johnson Grant/research support from: Boehringer Ingelheim, Corbus Pharmaceuticals, GlaxoSmithKline, Roche, Merck, Bayer, Consultant of: Boehringer Ingelheim, Ikaria, Ralph Brinks: None declared, Karen Costenbader Grant/research support from: Merck, Consultant of: Astra-Zeneca, David Daikh: None declared, Marta Mosca: None declared, Rosalind Ramsey-Goldman: None declared, Josef S. Smolen Grant/research support from: AbbVie, Eli Lilly, Janssen, Merck Sharp & Dohme, Pfizer, Roche – grant/research support, Consultant of: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene Corporation, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Sanofi, UCB – consultant, Speakers bureau: AbbVie, Amgen Inc., AstraZeneca, Astro, Celgene Corporation, Celtrion, Eli Lilly, Glaxo, ILTOO, Janssen, Medimmune, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Sanofi, UCB – speaker, David Wofsy: None declared, Dimitrios Boumpas Grant/research support from: Unrestricted grant support from various pharmaceutical companies, Diane L Kamen Consultant of: Consulted on SLE survey development for Lilly and consulted on SLE trial protocol development for EMD Serono in 2019, David Jayne Grant/research support from: ChemoCentryx, GSK, Roche/Genentech, Sanofi-Genzyme, Consultant of: Astra-Zeneca, ChemoCentryx, GSK, InflaRx, Takeda, Insmed, Chugai, Boehringer-Ingelheim, Ricard Cervera: None declared, Nathalie Costedoat-Chalumeau Grant/research support from: UCB to my institution, Betty Diamond: None declared, Dafna D Gladman Grant/research support from: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – grant/research support, Consultant of: AbbVie, Amgen Inc., BMS, Celgene Corporation, Janssen, Novartis, Pfizer, UCB – consultant, Bevra H. Hahn Grant/research support from: Janssen Research & Development, LLC, Falk Hiepe: None declared, Soren Jacobsen: None declared, Dinesh Khanna Shareholder of: Eicos Sciences, Inc./Civi Biopharma, Inc., Grant/research support from: Dr Khanna was supported by NIH/NIAMS K24AR063120, Consultant of: Acceleron, Actelion, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Corbus Pharmaceuticals, Horizon Therapeutic, Galapagos, Roche/Genentech, GlaxoSmithKline, Mitsubishi Tanabe, Sanofi-Aventis/Genzyme, UCB, Kirsten Lerstrom: None declared, Elena Massarotti: None declared, William Joseph McCune: None declared, Guillermo Ruiz-Irastorza: None declared, Jorge Sanchez-Guerrero: None declared, Matthias Schneider: None declared, Murray B Urowitz: None declared, George Bertsias Grant/research support from: GSK, Consultant of: Novartis, Bimba F. Hoyer: None declared, Nicolai Leuchten: None declared, Chiara Tani: None declared, Sara Tedeschi: None declared, Zahi Touma: None declared, Gabriela Schmajuk Grant/research support from: Pfizer, Branimir Anic: None declared, Florence Assan: None declared, Tak Chan: None declared, Ann E Clarke: None declared, Mary K. Crow: None declared, László Czirják Consultant of: Actelion, BI, Roche-Genentech, Lilly, Medac, Novartis, Pfizer, Bayer AG, Andrea Doria Consultant of: GSK, Pfizer, Abbvie, Novartis, Ely Lilly, Speakers bureau: UCB pharma, GSK, Pfizer, Janssen, Abbvie, Novartis, Ely Lilly, BMS, Winfried Graninger: None declared, Bernadett Halda-Kiss: None declared, Sarfaraz Hasni: None declared, Peter Izmirly: None declared, Michelle Jung: None declared, Gabor Kumanovics Consultant of: Boehringer, Teva, Speakers bureau: Roche, Lilly, Novartis, Xavier Mariette: None declared, Ivan Padjen: None declared, Jose M Pego-Reigosa: None declared, Juanita Romero-Diaz Consultant of: Biogen, Iñigo Rua-Figueroa: None declared, Raphaèle Seror Consultant of: BMS, Medimmune, Novartis, Pfizer, GSK, Lilly, Georg Stummvoll: None declared, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin, Maria Tektonidou Grant/research support from: AbbVie, MSD, Novartis and Pfizer, Consultant of: AbbVie, MSD, Novartis and Pfizer, Carlos Vasconcelos: None declared, Edward Vital Grant/research support from: AstraZeneca, Roche/Genentech, and Sandoz, Consultant of: AstraZeneca, GSK, Roche/Genentech, and Sandoz, Speakers bureau: Becton Dickinson and GSK, Daniel J Wallace: None declared, Sule Yavuz: None declared, Pier Luigi Meroni: None declared, Marvin Fritzler: None declared, Raymond Naden: None declared, Thomas Dörner Grant/research support from: Janssen, Novartis, Roche, UCB, Consultant of: Abbvie, Celgene, Eli Lilly, Roche, Janssen, EMD, Speakers bureau: Eli Lilly, Roche, Samsung, Janssen, Martin Aringer Consultant of: Boehringer Ingelheim, Roche, Speakers bureau: Boehringer Ingelheim, Roche

Blood transfusions in total knee arthroplasty: a retrospective analysis of a multimodal patient blood management programme

PURPOSE

Transfusion is associated with increased perioperative morbidity and mortality in patients undergoing total knee arthroplasty (TKA). Patient blood management (PBM) is an evidence-based approach to maintain blood mass via haemoglobin maintenance, haemostasis optimisation, and blood loss minimisation. The aim of the present study was to assess the effectiveness of a multimodal PBM approach in our centre.

METHODS

This was a single-centre retrospective study of patients who underwent primary TKA in Queen Mary Hospital in Hong Kong in 2013 or 2018, using data from the Clinical Data Analysis and Reporting System and a local joint registry database. Patient demographics, preoperative haemoglobin, length of stay, readmission, mean units of transfusion, postoperative prosthetic joint infection, and mortality data were compared between groups.

RESULTS

In total, 262 and 215 patients underwent primary TKA in 2013 and 2018, respectively. The mean transfusion rate significantly decreased after PBM implementation (2013: 31.3%; 2018: 1.9%, P<0.001); length of stay after TKA also significantly decreased (2013: 14.49±8.10 days; 2018: 8.77±10.14 days, P<0.001). However, there were no statistically significant differences in readmission, early prosthetic joint infection, or 90-day mortality rates between the two groups.

CONCLUSION

Our PBM programme effectively reduced the allogeneic blood transfusion rate in patients undergoing TKA in our institution. Thus, PBM should be considered in current TKA protocols to reduce rates of transfusions and related complications.

Climate adaptation for rural water and sanitation systems in the Solomon Islands: A community scale systems model for decision support

Delivering water and sanitation services are challenging in data poor rural settings in developing countries. In this paper we develop a Bayesian Belief Network model that supports decision making to increase the availability of safe drinking water in five flood-prone rural communities in the Solomon Islands. We collected quantitative household survey data and qualitative cultural and environmental knowledge through community focus group discussions. We combined these data to develop our model, which simulates the state of eight water sources and ten sanitation types and how they are affected by season and extreme events. We identify how climate and current practices can threaten the availability of drinking water for remote communities. Modelling of climate and intervention scenarios indicate that water security could be best enhanced through increased rainwater harvesting (assuming proper installation and maintenance). These findings highlight how a systems model can identify links between and improve understanding of water and sanitation, community behaviour, and the impacts of extreme events. The resultant BBN provides a tool for decision support to enhance opportunities for climate resilient water and sanitation service provision.

Open abdomen in liver transplantation

INTRODUCTION

Damage control laparotomy with vacuum assisted closure (VAC) is used for selective cases in trauma. In liver transplantation, VAC has also been applied for management of intra-operative hemorrhage. The primary objective was to evaluate peri-operative blood loss and blood product utilization in VAC compared to primary abdominal closure (PAC) at the index transplant operation.

METHODS

Retrospective review of all adults undergoing deceased donor liver transplantation (2007-2011) at a single center tertiary care institution.

RESULTS

201 deceased donor liver transplantations were performed, with 167 PAC and 34 VAC cases. Intra-operative blood loss (4.4L vs 10.7L), cell saver return (1399 ml vs 3998 ml), FFP (7.6U vs 15.9U) and PLT requirements (8.5U vs 18.3U), were all significantly elevated in VAC compared to PAC. VAC patients had significantly increased RBC, FFP, PLT, and total volume requirements during initial ICU admission. 30 PAC cases required on demand laparotomy and most commonly for post-operative bleeding.

CONCLUSION

In liver transplantation, application of VAC secondary to massive intra-operative exsanguination was safely utilized. Further evaluation is required to identify long-term morbidity and mortality.

In vitro fracture strength and patterns in root-filled teeth restored with different base materials

BACKGROUND

There is little research on the effects of an intermediate base on the fracture strength of root-filled teeth. This study compared the fracture strengths and patterns of root-filled teeth restored with intermediate bases of glass-ionomer cement (GIC), zinc polycarboxylate cement (ZPC), dual-cured resin composite (DCRC) and Biodentine^® under resin composite.

METHODS

Standardized cavities were prepared in 100 extracted human maxillary and mandibular premolars, and root canal treatment was performed. The teeth were stratified and randomly allocated to five groups (n = 20): (i) GIC; (ii) ZPC; (iii) DCRC; (iv) Biodentine; and (v) prepared but unrestored (control). The teeth were subjected to an oblique, ramped load until fracture. The fracture loads, level, mode and location were recorded.

RESULTS

Mean fracture strengths of all restored groups were not significantly different amongst the groups. There were significant overall effects on mean fracture strength for tooth type (P = 0.002) and buccolingual width of the crown (P = 0.001).

CONCLUSIONS

The four materials were appropriate intermediate bases. The laminate restorative technique promoted fracture strengths that are likely to withstand normal and maximum masticatory function. The base material can influence failure mode, which may have implications for the clinical presentation of fractures of root-filled teeth.

Randomized phase II study of modified FOLFOX-6 in combination with ramucirumab or icrucumab as second-line therapy in patients with metastatic colorectal cancer after disease progression on first-line irinotecan-based therapy

BACKGROUND

Icrucumab and ramucirumab are recombinant human IgG1 monoclonal antibodies that bind VEGF receptors 1 and 2 (VEGFR-1 and -2), respectively. This randomized phase II study evaluated the antitumor activity and safety of icrucumab and ramucirumab each in combination with mFOLFOX-6 in patients with metastatic colorectal cancer after disease progression on first-line therapy with a fluoropyrimidine and irinotecan.

PATIENTS AND METHODS

Eligible patients were randomly assigned to receive mFOLFOX-6 alone (mFOLFOX-6) or in combination with ramucirumab 8 mg/kg IV (RAM+mFOLFOX-6) or icrucumab 15 mg/kg IV (ICR+mFOLFOX-6) every 2 weeks. Randomization was stratified by prior bevacizumab therapy. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), tumor response, safety, and PK.

RESULTS

In total, 158 patients were randomized, but only 153 received treatment (49 on mFOLFOX-6, 52 on RAM+mFOLFOX-6, and 52 on ICR+mFOLFOX-6). Median PFS was 18.4 weeks on mFOLFOX-6, 21.4 weeks on RAM+mFOLFOX-6, and 15.9 weeks on ICR+mFOLFOX-6 (RAM+mFOLFOX-6 versus mFOLFOX-6, stratified hazard ratio [HR] 1.116 [95% CI 0.713-1.745], P = 0.623; ICR+mFOLFOX-6 versus mFOLFOX-6, stratified HR 1.603 [95% CI 1.011-2.543], P = 0.044). Median survival was 53.6 weeks on mFOLFOX-6, 41.7 weeks on RAM+mFOLFOX-6, and 42.0 weeks on ICR+mFOLFOX-6. The most frequent adverse events reported on the ramucirumab arm (RAM+mFOLFOX-6) were fatigue, nausea, and peripheral sensory neuropathy; those on the icrucumab arm (ICR+mFOLFOX-6) were fatigue, diarrhea, and peripheral sensory neuropathy. Grade ≥3 serious adverse events occurred at comparable frequency across arms.

CONCLUSIONS

In this study population, combining ramucirumab or icrucumab with mFOLFOX-6 did not achieve the predetermined improvement in PFS.

CLINICALTRIALSGOV

NCT01111604.

13-week dietary study and in vitro and in vivo genotoxicity studies of a structuring fat produced through a microalgal fermentation process

Microalgae are increasingly being utilized as food ingredients for a variety of applications, including as sources of protein, egg and dairy substitutes, and cooking oils. The dietary safety of a new structuring fat produced using a heterotrophic fermentation process by a strain of Prototheca moriformis was evaluated in a 13-week dietary toxicity study and compared with kokum fat, a structuring fat of similar composition used in the food industry and derived from Garcinia indica seeds. The algal structuring fat was evaluated for its genotoxic potential using both in vitro and in vivo assays. No treatment-related adverse events occurred in rats consuming algal structuring fat or kokum fat in the 13-week study; no treatment-related effects were reported for body weight, food consumption, urinalysis, hematology, clinical chemistry, gross pathology, organ weights, or histopathology. While statistically significant effects occurred in some parameters, none were dose-related or considered adverse. Overall, the NOAELs for the algal structuring fat and the kokum fat were 100 000 ppm, the highest concentrations tested. The algal structuring fat was not mutagenic in the bacterial reverse mutation assay in the Salmonella typhimurium or Escherichia coli strains tested and was not clastogenic in the in vivo mouse bone marrow chromosome aberration assay.