A review of analytical parameters in 'rapid' liquid chromatographic methods for bioanalysis: Can we do better?

Rapid bioanalysis is beneficial to many applications. However, how 'rapid' a method is, or could be, is often an unanswered question. In this statistical review, the authors have assessed multiple pre-analytical (i.e. sample preparation), and analytical method parameters specifically for liquid chromatography to assist researchers in developing and validating 'rapid' bioanalytical methods. We restricted the search to urine and plasma matrices only. Data were extracted from over 2,000 recent studies and evaluated to assess how these parameters affected the 'on-instrument' analysis time. In addition to methods using ultra-violet (UV) detection, there were a large number of mass spectrometric (MS) methods, allowing additional review of the differences between high- and low-resolution MS on analysis time. We observed that most (N = 922, 70 %) methods used 5 or 10 cm columns, and that whilst uptake of ultra-high performance (U)HPLC columns was good, the use of sub-5 cm columns and/or flow rates in excess of 1 mL/min was incredibly rare (N = 25, 3 %). The detector of choice for quantitative (U)HPLC-MS remains the triple quadrupole, although a number of groups report the use of high-resolution MS for such methods.

Pegargiminase Plus First-Line Chemotherapy in Patients With Nonepithelioid Pleural Mesothelioma: The ATOMIC-Meso Randomized Clinical Trial

Importance

Arginine deprivation using ADI-PEG20 (pegargiminase) combined with chemotherapy is untested in a randomized study among patients with cancer. ATOMIC-Meso (ADI-PEG20 Targeting of Malignancies Induces Cytotoxicity-Mesothelioma) is a pivotal trial comparing standard first-line chemotherapy plus pegargiminase or placebo in patients with nonepithelioid pleural mesothelioma.

Objective

To determine the effect of pegargiminase-based chemotherapy on survival in nonepithelioid pleural mesothelioma, an arginine-auxotrophic tumor.

Design, Setting, and Participants

This was a phase 2-3, double-blind randomized clinical trial conducted at 43 centers in 5 countries that included patients with chemotherapy-naive nonepithelioid pleural mesothelioma from August 1, 2017, to August 15, 2021, with at least 12 months' follow-up. Final follow-up was on August 15, 2022. Data analysis was performed from March 2018 to June 2023.

Intervention

Patients were randomly assigned (1:1) to receive weekly intramuscular pegargiminase (36.8 mg/m2) or placebo. All patients received intravenous pemetrexed (500 mg/m2) and platinum (75-mg/m2 cisplatin or carboplatin area under the curve 5) chemotherapy every 3 weeks up to 6 cycles. Pegargiminase or placebo was continued until progression, toxicity, or 24 months.

Main Outcomes and Measures

The primary end point was overall survival, and secondary end points were progression-free survival and safety. Response rate by blinded independent central review was assessed in the phase 2 portion only.

Results

Among 249 randomized patients (mean [SD] age, 69.5 [7.9] years; 43 female individuals [17.3%] and 206 male individuals [82.7%]), all were included in the analysis. The median overall survival was 9.3 months (95% CI, 7.9-11.8 months) with pegargiminase-chemotherapy as compared with 7.7 months (95% CI, 6.1-9.5 months) with placebo-chemotherapy (hazard ratio [HR] for death, 0.71; 95% CI, 0.55-0.93; P = .02). The median progression-free survival was 6.2 months (95% CI, 5.8-7.4 months) with pegargiminase-chemotherapy as compared with 5.6 months (95% CI, 4.1-5.9 months) with placebo-chemotherapy (HR, 0.65; 95% CI, 0.46-0.90; P = .02). Grade 3 to 4 adverse events with pegargiminase occurred in 36 patients (28.8%) and with placebo in 21 patients (16.9%); drug hypersensitivity and skin reactions occurred in the experimental arm in 3 patients (2.4%) and 2 patients (1.6%), respectively, and none in the placebo arm. Rates of poststudy treatments were comparable in both arms (57 patients [45.6%] with pegargiminase vs 58 patients [46.8%] with placebo).

Conclusions and Relevance

In this randomized clinical trial of arginine depletion with pegargiminase plus chemotherapy, survival was extended beyond standard chemotherapy with a favorable safety profile in patients with nonepithelioid pleural mesothelioma. Pegargiminase-based chemotherapy as a novel antimetabolite strategy for mesothelioma validates wider clinical testing in oncology.

Trial Registration

ClinicalTrials.gov Identifier: NCT02709512.

How comparable are patient outcomes in the "real-world" with populations studied in pivotal AML trials?

Despite an increasing desire to use historical cohorts as "synthetic" controls for new drug evaluation, limited data exist regarding the comparability of real-world outcomes to those in clinical trials. Governmental cancer data often lacks details on treatment, response, and molecular characterization of disease sub-groups. The Australasian Leukaemia and Lymphoma Group National Blood Cancer Registry (ALLG NBCR) includes source information on morphology, cytogenetics, flow cytometry, and molecular features linked to treatment received (including transplantation), response to treatment, relapse, and survival outcome. Using data from 942 AML patients enrolled between 2012-2018, we assessed age and disease-matched control and interventional populations from published randomized trials that led to the registration of midostaurin, gemtuzumab ozogamicin, CPX-351, oral azacitidine, and venetoclax. Our analyses highlight important differences in real-world outcomes compared to clinical trial populations, including variations in anthracycline type, cytarabine intensity and scheduling during consolidation, and the frequency of allogeneic hematopoietic cell transplantation in first remission. Although real-world outcomes were comparable to some published studies, notable differences were apparent in others. If historical datasets were used to assess the impact of novel therapies, this work underscores the need to assess diverse datasets to enable geographic differences in treatment outcomes to be accounted for.

1295 CAN THE HOSPITAL FRAILTY RISK SCORE BE USED TO PREDICT POST-OPERATIVE OUTCOMES IN SPINAL SURGERY?

Introduction

Frailty is a syndrome associated with increasing numbers of elderly hospital admissions and prolonged inpatient stays (Archibald et al, Geriatrics, 2020, 20, 17). In 2015, an estimated 14% of inpatients in the UK were considered to have a degree of frailty, representing an approximate annual cost to the NHS of £5.8 billion (Soong et al, BMJ Open, 2015, 5, e008456; Han et al, Age and Aging, 2019, 48, 665-671). Frailty is poorly defined; there are discrepancies in existing literature on how to best quantify frailty. It is recognised there is a higher risk of adverse outcomes in this vulnerable population due to lack of physiological reserve (Clegg et al, The Lancet, 2013, 381, 752-762). The Hospital Frailty Risk Score (HFRS) is a recent development to measure frailty and identify patients at risk (Gilbert et al, The Lancet, 2018, 391, 1775-1782). This study sought to establish whether the HFRS could be used in patients with degenerative spinal disease, undergoing decompression surgery, to predict post-operative outcomes.

Methods

A retrospective service evaluation of eligible patients in Leeds Teaching Hospitals Trust between March 2018 - March 2020. The exposure was the patients’ HFRS; the outcome was the length of stay (LOS) until physiotherapy discharge. Data was sourced from electronic records.

Results

214 patients were identified with an available HFRS value. Patients were categorised as low, intermediate or high frailty. Kruskal-Wallis test for LOS and categorical HFRS: X2 =8.673, p<0.05. The median HFRS value was 1.25 (interquartile range 0.00 to 3.35). Mann-Whitney U test for LOS and numerical HFRS: W=29297, p<0.05.

Conclusions

The results of this study complement pre-existing studies of similar natures, evaluating frailty scoring and post-operative outcomes, thus, supporting the potential for standardised use of HFRS alongside holistic patient examination to streamline pre-assessment, improve outcomes and reduce the NHS frailty burden.

Multi-perspective region-based CNNs for vertebrae labeling in intraoperative long-length images

PURPOSE

Effective aggregation of intraoperative x-ray images that capture the patient anatomy from multiple view-angles has the potential to enable and improve automated image analysis that can be readily performed during surgery. We present multi-perspective region-based neural networks that leverage knowledge of the imaging geometry for automatic vertebrae labeling in Long-Film images - a novel tomographic imaging modality with an extended field-of-view for spine imaging.

METHOD

A multi-perspective network architecture was designed to exploit small view-angle disparities produced by a multi-slot collimator and consolidate information from overlapping image regions. A second network incorporates large view-angle disparities to jointly perform labeling on images from multiple views (viz., AP and lateral). A recurrent module incorporates contextual information and enforce anatomical order for the detected vertebrae. The three modules are combined to form the multi-view multi-slot (MVMS) network for labeling vertebrae using images from all available perspectives. The network was trained on images synthesized from 297 CT images and tested on 50 AP and 50 lateral Long-Film images acquired from 13 cadaveric specimens. Labeling performance of the multi-perspective networks was evaluated with respect to the number of vertebrae appearances and presence of surgical instrumentation.

RESULTS

The MVMS network achieved an F1 score of >96% and an average vertebral localization error of 3.3 mm, with 88.3% labeling accuracy on both AP and lateral images - (15.5% and 35.0% higher than conventional Faster R-CNN on AP and lateral views, respectively). Aggregation of multiple appearances of the same vertebra using the multi-slot network significantly improved the labeling accuracy (p < 0.05). Using the multi-view network, labeling accuracy on the more challenging lateral views was improved to the same level as that of the AP views. The approach demonstrated robustness to the presence of surgical instrumentation, commonly encountered in intraoperative images, and achieved comparable performance in images with and without instrumentation (88.9% vs. 91.2% labeling accuracy).

CONCLUSION

The MVMS network demonstrated effective multi-perspective aggregation, providing means for accurate, automated vertebrae labeling during spine surgery. The algorithms may be generalized to other imaging tasks and modalities that involve multiple views with view-angle disparities (e.g., bi-plane radiography). Predicted labels can help avoid adverse events during surgery (e.g., wrong-level surgery), establish correspondence with labels in preoperative modalities to facilitate image registration, and enable automated measurement of spinal alignment metrics for intraoperative assessment of spinal curvature.

A systematic review of validated case-finding definitions to identify hypertensive disorders of pregnancy in administrative healthcare databases

Background

Administrative healthcare data are frequently used to study cardiovascular disease (CVD) risk in women with hypertensive disorders of pregnancy (HDP); however, little is known about the validity of case-finding definitions (CFDs, e.g., International Classification of Disease codes/algorithms) designed to identify these conditions in administrative databases.

Purpose

To systematically identify and summarize available evidence on the validity of administrative CFDs for HDP.

Methods

Four bibliographic databases and grey literature sources were searched for eligible studies. The titles/abstracts of all records were independently screened for eligibility by two reviewers, then assessed at full text. Study data (design and participant characteristics, validation statistics) were extracted by two independent reviewers and discrepancies resolved through consensus. Quality of reporting was assessed using checklists; risk of bias was assessed using a modified version of the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool, adapted for administrative validation studies.

Results

Twenty-five studies, published between 1998 and 2021, met the eligibility criteria. Nearly half (48%) were conducted in the United States. Ten studies validated CFDs for ≥1 HDP as a primary aim; most (60%) validated several maternal and infant morbidities, including ≥1 HDP. Preeclampsia (any, mild, moderate, serious, severe, superimposed) was the most validated HDP subtype. Only six studies reported gold standard definitions for all HDPs validated; definitions were heterogeneous with respect to blood pressure thresholds and timing of diagnosis. Seven studies (∼25%) reported all 2x2 table values (true positives/negatives, false positives/negatives) for ≥1 CFD, or they were calculable. The majority of CFDs reported in primary analyses (n=23) were highly specific (≥98%); however, sensitivity varied widely (3.2% to 100%; Figure 1). Nearly all (n=20, 87%) had a positive predictive value (PPV) of ≥70%, 13 of which had a PPV of &gt;80% in combination with high specificity. Across studies, HDP prevalence ranged from 0.1% (eclampsia) to 37% (any maternal hypertensive disorder). Quality of reporting was generally poor to moderate, and all studies were judged to be at unclear or high risk of bias on ≥1 QUADAS-2 domain. Five studies were judged to be of “low concern” regarding study applicability (Figure 2).

Conclusions

Clinical understanding of CVD risk in women with HDP could be drastically impacted if there is low confidence that these conditions have been correctly identified from administrative data. Researchers should quantitatively explore the extent to which CVD risk estimates may be impacted by CFDs with low sensitivity and artificially inflated PPVs, influenced by greater study prevalence of HDP than would be expected in the general population. Higher quality validation studies that employ more rigorous methodology and improved reporting are needed.

Funding Acknowledgement

Type of funding sources: None.

1009 Severe Thoracic and Abdominal Surgical Emphysema in a Patient with COVID-19 Pneumonia

Introduction

Surgical emphysema is a relatively common occurrence in intensive care unit but its degree of spread in our patient is unusual. We present a case of a young adult with rapid widespread crepitus and worsening respiratory dynamics.

Case description

35-year-old male with hypertension, type 2 diabetes and obesity was invasively ventilated for severe COVID-19 pneumonia. He developed reduced chest compliance, required high driving pressures, and had persistent hypoxia despite a high fraction of inspired oxygen. He was ventilated using protocolised ARDSNet lung protective ventilation (LPV) including periods of ventilation in the prone position. After 19 days of ventilation, worsening surgical emphysema was noted following a tracheostomy. Chest radiography demonstrated extensive extra-pulmonary air. Subsequent computed tomography confirmed widespread surgical emphysema from the face to the scrotum, bilateral pneumothoraces and pneumoperitoneum. Bilateral intercostal drains were inserted and LPV was continued. The pneumoperitoneum resolved with conservative management. The patient was mechanically ventilated for 59 days and was discharged home on day 104.

Discussion

Pneumothorax, pneumomediastinum and surgical emphysema can occur following high-pressure ventilation and surgical tracheostomy. However, pneumoperitoneum with extra-alveolar air collections communicating via potential fascial planes, perivascular sheaths or trans-diaphragmatic extension is rare. The cytokine storm postulated to occur in COVID-19 infection may cause alveolar destruction, leading to Macklin's phenomenon whereby air tracks along peri-bronchial vascular sheaths towards the mediastinum following alveolar rupture. In this patient, prolonged ventilation and high airway pressures probably compounded this effect and led to the complications described.

A Phase 1 study of ADI-PEG20 (pegargiminase) combined with cisplatin and pemetrexed in ASS1-negative metastatic uveal melanoma

Metastatic uveal melanoma (UM) is a devastating disease with few treatment options. We evaluated the safety, tolerability and preliminary activity of arginine depletion using pegylated arginine deiminase (ADI‐PEG20; pegargiminase) combined with pemetrexed (Pem) and cisplatin (Cis) chemotherapy in a phase 1 dose‐expansion study of patients with argininosuccinate synthetase (ASS1)‐deficient metastatic UM. Eligible patients received up to six cycles of Pem (500 mg/m²) and Cis (75 mg/m²) every 3 weeks plus weekly intramuscular ADI (36 mg/m²), followed by maintenance ADI until progression (NCT02029690). Ten of fourteen ASS1‐deficient patients with UM liver metastases and a median of one line of prior immunotherapy received ADIPemCis. Only one ≥ grade 3 adverse event of febrile neutropenia was reported. Seven patients had stable disease with a median progression‐free survival of 3.0 months (range, 1.3–8.1) and a median overall survival of 11.5 months (range, 3.2–36.9). Despite anti‐ADI‐PEG20 antibody emergence, plasma arginine concentrations remained suppressed by 18 weeks with a reciprocal increase in plasma citrulline. Tumour rebiopsies at progression revealed ASS1 re‐expression as an escape mechanism. ADIPemCis was well tolerated with modest disease stabilisation in metastatic UM. Further investigation of arginine deprivation is indicated in UM including combinations with immune checkpoint blockade and additional anti‐metabolite strategies.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

British Journal of Surgery Society.

Aberrant Neural Activity in Prefrontal Pyramidal Neurons Lacking TDP-43 Precedes Neuron loss

Mislocalization of TAR DNA binding protein 43 kDa (TARDBP, or TDP-43) is a principal pathological hallmark identified in cases of neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). As an RNA binding protein, TDP-43 serves in the nuclear compartment to repress non-conserved cryptic exons to ensure the normal transcriptome. Multiple lines of evidence from animal models and human studies support the view that loss of TDP-43 leads to neuron loss, independent of its cytosolic aggregation. However, the underlying pathogenic pathways driven by the loss-of-function mechanism are still poorly defined. We employed a genetic approach to determine the impact of TDP-43 loss in pyramidal neurons of the prefrontal cortex (PFC). Using a custom-built miniscope imaging system, we performed repetitive in vivo calcium imaging from freely behaving mice for up to 7 months. By comparing calcium activity in PFC pyramidal neurons between TDP-43 depleted and TDP-43 intact mice, we demonstrated remarkably increased numbers of pyramidal neurons exhibiting hyperactive calcium activity after short-term TDP-43 depletion, followed by rapid activity declines prior to neuron loss. Our results suggest aberrant neural activity driven by loss of TDP-43 as the pathogenic pathway at early stage in ALS and FTD.

Phase IB trial of pegylated arginine deiminase (ADI-PEG 20) plus radiotherapy and temozolomide in patients with newly diagnosed glioblastoma

2057

Background: ADI-PEG 20 exploits the different metabolic ability for synthesizing arginine (Arg) between normal and neoplastic cells to reduce tumor cell growth. Preclinical and clinical studies have shown that cancers which are either Arg auxotrophic, with silencing of argininosuccinate synthetase ( ASS1), or Arg non-auxotrophic, respond to ADI-PEG 20 monotherapy or ADI-PEG 20 combined with various chemotherapies, respectively. ADI-PEG 20 has shown efficacy as monotherapy in ASS1 negative mouse glioblastoma (GBM) models and the combination of ADI-PEG 20 with temozolomide (TMZ) and with radiation (RT) in both ASS1 negative and ASS1 positive mouse GBM models. Based on these rationales, ADI-PEG 20 was added to standard RT + TMZ in patients with newly diagnosed GBM. This is the first clinical trial combining ADI-PEG 20 with RT. Methods: This phase IB, open-label, single-arm, standard 3+3 dose escalation with a recommended phase 2 dose (RP2D) expansion study (NCT04587830) was initiated in June 2020. Weekly ADI-PEG 20 is added to concurrent RT + TMZ and to 6 cycles of adjuvant TMZ (Stupp protocol). ADI-PEG 20 could be continued for up to 2 years. RANO criteria are used to determine response by evaluating MRI at 1, 3 and 6 months after RT, and every 3 months thereafter. Major eligibility criteria are age 20-75 years with newly diagnosed, histologically confirmed GBM with Karnofsky performance status ≥ 60. Endpoints include safety, pharmacodynamics, immunogenicity, progression free survival (PFS) and overall survival (OS). Results: Cohorts 1 (18 mg/m2) and 2 (36 mg/m2) were completed without dose limiting toxicity (DLT). Enrollment to cohort 3 (RP2D phase, 36 mg/m2) is ongoing with 23/26 patients. The major adverse events (AEs) were fatigue (52%), constipation (39%) and neutrophil decrease (39%). Dermatologic or allergic reactions occurred in 12/23 (52%), and all were grade 1-2 except for anaphylactic shock in 1 and vasculitis/rash in 1. 22/23 are alive, with median PFS = 9.5 months. The first 6 study patients are all alive for at least 11 months, with the longest at 1.5 years. 10 are off treatment due to progressive disease in 6, severe AE in 2, consent withdrawal in 1, and medical decision in 1. Mean peripheral blood Arg levels were suppressed ( < 10uM) for 4-6 weeks in most subjects, with a reciprocal elevation of citrulline levels. Anti-ADI-PEG 20 antibodies tended to increase as peripheral Arg levels increased. Conclusions: The addition of ADI-PEG 20 to RT + TMX was safe, and no DLT was observed. The RP2D of ADI-PEG 20 was determined to be 36mg/m2. AEs were those typically seen with RT + TMZ, with perhaps an increase in rash reported with the addition of ADI-PEG 20. Anaphylaxis and vasculitis were seen (1 subject with each), and have been observed previously with ADI-PEG 20. The preliminary OS data are encouraging. A registration phase 2/3 trial of this triplet is being considered. Clinical trial information: NCT04587830.

Experimental Search for Neutron to Mirror Neutron Oscillations as an Explanation of the Neutron Lifetime Anomaly

An unexplained >4σ discrepancy persists between "beam" and "bottle" measurements of the neutron lifetime. A new model proposed that conversions of neutrons n into mirror neutrons n^{'}, part of a dark mirror sector, can increase the apparent neutron lifetime by 1% via a small mass splitting Δm between n and n^{'} inside the 4.6 T magnetic field of the National Institute of Standards and Technology Beam Lifetime experiment. A search for neutron conversions in a 6.6 T magnetic field was performed at the Spallation Neutron Source which excludes this explanation for the neutron lifetime discrepancy.

Pilot Trial of Arginine Deprivation Plus Nivolumab and Ipilimumab in Patients with Metastatic Uveal Melanoma

Simple Summary

Uveal melanoma is a rare subtype of malignant melanoma. It is known to rapidly metastasize, with the liver being the most frequently affected organ. Due to differences from melanoma arising in the skin, such as a lower number of mutations, it responds poorly to immune checkpoint blockade, a treatment approach reinvigorating the patient’s immune system to eliminate the cancer. We here investigated the safety and tolerability of a new combination treatment consisting of two established immunotherapy medications (ipilimumab and nivolumab) with the addition of an experimental arginine depleting medication, pegylated arginine deiminase (ADI-PEG 20), which is thought to make uveal melanoma more amenable to immunotherapy. This novel treatment approach was found to be safe and well-tolerated but did not improve the clinical outcome beyond the expected limited efficacy of approved immunotherapy alone.

Abstract

Metastatic uveal melanoma (UM) remains challenging to treat, with objective response rates to immune checkpoint blockade (ICB) being much lower than in primary cutaneous melanoma (CM). Besides a lower mutational burden, the overall immune-excluded tumor microenvironment of UM might contribute to the poor response rate. We therefore aimed at targeting deficiency in argininosuccinate synthase 1, which is a key metabolic feature of UM. This study aims at investigating the safety and tolerability of a triple combination consisting of ipilimumab and nivolumab immunotherapy and the metabolic therapy, ADI-PEG 20. Nine patients were enrolled in this pilot study. The combination therapy was safe and tolerable with an absence of immune-related adverse events (irAE) of special interest, but with four of nine patients experiencing a CTCAE grade 3 AE. No objective responses were observed. All except one patient developed anti-drug antibodies (ADA) within a month of the treatment initiation and therefore did not maintain arginine depletion. Further, an IFNg-dependent inflammatory signature was observed in metastatic lesions in patients pre-treated with ICB compared with patients with no pretreatment. Multiplex immunohistochemistry demonstrated variable presence of tumor infiltrating CD8 lymphocytes and PD-L1 expression at the baseline in metastases.

Phase 1 trial of ADI-PEG 20 and liposomal doxorubicin in patients with metastatic solid tumors

Background

Arginine depletion interferes with pyrimidine metabolism and DNA damage repair pathways. Preclinical data demonstrated that depletion of arginine by PEGylated arginine deiminase (ADI‐PEG 20) enhanced liposomal doxorubicin (PLD) cytotoxicity in cancer cells with argininosuccinate synthase 1 (ASS1) deficiency. The objective of this study was to assess safety and tolerability of ADI‐PEG 20 and PLD in patients with metastatic solid tumors.

Methods

Patients with advanced ASS1‐deficient solid tumors were enrolled in this phase 1 trial of ADI‐PEG 20 and PLD following a 3 + 3 design. Eligible patients were given intravenous PLD biweekly and intramuscular (IM) ADI‐PEG 20 weekly. Toxicity and efficacy were evaluated according to the Common Terminology Criteria for Adverse Events (version 4.0) and Response Evaluation Criteria in Solid Tumors (version 1.1), respectively.

Results

Of 15 enrolled patients, 9 had metastatic HER2‐negative breast carcinoma. We observed no dose‐limiting toxicities or treatment‐related deaths. One patient safely received 880 mg/m² PLD in this study and 240 mg/m² doxorubicin previously. Treatment led to stable disease in 9 patients and was associated with a median progression‐free survival time of 3.95 months in 15 patients. Throughout the duration of treatment, decreased arginine and increased citrulline levels in peripheral blood remained significant in a majority of patients. We detected no induction of anti‐ADI‐PEG 20 antibodies by week 8 in one third of patients.

Conclusion

Concurrent IM injection of ADI‐PEG 20 at 36 mg/m² weekly and intravenous infusion of PLD at 20 mg/m² biweekly had an acceptable safety profile in patients with advanced ASS1‐deficient solid tumors. Further evaluation of this combination is under discussion.

Current management of adults receiving oral anti-cancer medications: A scoping review

PURPOSE

Oral anti-cancer medication (OAM) has revolutionised oncology care. Due to their potential toxicities and associated safety challenges ongoing assessment and monitoring is essential; currently generally performed in acute care settings. Internationally there exists a transformative vision to shift patient care from acute to primary care. A nurse-led integrated model of care could be developed for OAM patient management in primary care. The aim of this study was to examine international literature regarding current clinical management practices for assessment and monitoring of patients receiving OAM.

METHODS

Following PRISMA-ScR guidelines, databases MEDLINE, CINAHL and Web of Science were searched for English studies published between 2010 and 2020 using keywords: assessment, cancer, care, management, oral anticancer medications. Articles were screened and assessed for eligibility. From eligible studies, data were extracted to summarize, collate and make a narrative account of the findings.

RESULTS

2261 papers were reviewed, 14 met inclusion criteria. Three phases of management are reported: 1. Patient treatment plan development; 2. Patient education; 3. Patient monitoring. Within these phases seven specific stages of care were identified broadly representing the patient's journey: (1) treatment decision, (2) prescribing of OAM, (3) OAM dispensing and administration, (4) maximising patient safety (5) ongoing patient assessment (6) patient support (7) communication with other health-care professionals.

CONCLUSIONS

Despite a paucity of international literature, a dedicated OAM clinic was endorsed as a means to achieve improved care. Nurses and pharmacists were identified as being of particular importance especially in education and ongoing management of patients receiving OAMs.

Assessment of pegylated arginine deiminase and modified FOLFOX6 in patients with advanced hepatocellular carcinoma: Results of an international, single-arm, phase 2 study

BACKGROUND

Arginine starvation depletes the micronutrients required for DNA synthesis and interferes with both thymidylate synthetase activity and DNA repair pathways in preclinical models of hepatocellular carcinoma (HCC). Pegylated arginine deiminase (ADI-PEG 20), an arginine degrader, potentiates the cytotoxic activity of platinum and pyrimidine antimetabolites in HCC cellular and murine models.

METHODS

This was a global, multicenter, open-label, single-arm, phase 2 trial of ADI-PEG 20 and modified 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) in patients who had HCC with Child-Pugh A cirrhosis and disease progression on ≥2 prior lines of treatment. The primary objective was the objective response rate assessed according to Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary objectives were to estimate progression-free survival, overall survival, safety, and tolerability. Eligible patients were treated with mFOLFOX6 intravenously biweekly at standard doses and ADI-PEG-20 intramuscularly weekly at 36 mg/m² .

RESULTS

In total, 140 patients with advanced HCC were enrolled. The median patient age was 62 years (range, 30-85 years), 83% of patients were male, 76% were of Asian race, 56% had hepatitis B viremia, 10% had hepatitis C viremia, 100% had received ≥2 prior lines of systemic therapy, and 39% had received ≥3 prior lines of systemic therapy. The objective response rate was 9.3% (95% confidence interval [CI], 5.0%-15.4%), with a median response duration of 10.2 months (95% CI, 5.8 months to not reached). The median progression-free survival was 3.8 months (95% CI, 1.8-6.3 months), and the median overall survival was 14.5 months (95% CI, 13.6-20.9 months). The most common grade ≥3 treatment-related events were neutropenia (32.9%), white blood cell count decrease (20%), platelet count decrease (19.3%), and anemia (9.3%).

CONCLUSIONS

Concurrent mFOLFOX6 plus ADI-PEG 20 exhibited limited antitumor activity in patients with treatment-refractory HCC. The study was terminated early, and no further evaluation of the combination will be pursued.

LAY SUMMARY

Arginine is an important nutrient for hepatocellular carcinoma (HCC). The depletion of arginine with pegylated arginine deiminase (ADI-PEG 20), an arginine degrader, appeared to make chemotherapy (FOLFOX) work better in animal models of HCC and in patients with HCC on an early phase clinical trial. To formally test this hypothesis in the clinical setting, a large, global, phase 2 clinical trial was conducted of ADI-PEG 20 and FOLFOX in the treatment of patients with refractory HCC. The study showed limited activity of ADI-PEG 20 and FOLFOX in advanced HCC and was stopped early.

Phase 1, pharmacogenomic, dose-expansion study of pegargiminase plus pemetrexed and cisplatin in patients with ASS1-deficient non-squamous non-small cell lung cancer

Introduction

We evaluated the arginine‐depleting enzyme pegargiminase (ADI‐PEG20; ADI) with pemetrexed (Pem) and cisplatin (Cis) (ADIPemCis) in ASS1‐deficient non‐squamous non‐small cell lung cancer (NSCLC) via a phase 1 dose‐expansion trial with exploratory biomarker analysis.

Methods

Sixty‐seven chemonaïve patients with advanced non‐squamous NSCLC were screened, enrolling 21 ASS1‐deficient subjects from March 2015 to July 2017 onto weekly pegargiminase (36 mg/m²) with Pem (500 mg/m²) and Cis (75 mg/m²), every 3 weeks (four cycles maximum), with maintenance Pem or pegargiminase. Safety, pharmacodynamics, immunogenicity, and efficacy were determined; molecular biomarkers were annotated by next‐generation sequencing and PD‐L1 immunohistochemistry.

Results

ADIPemCis was well‐tolerated. Plasma arginine and citrulline were differentially modulated; pegargiminase antibodies plateaued by week 10. The disease control rate was 85.7% (n = 18/21; 95% CI 63.7%–97%), with a partial response rate of 47.6% (n = 10/21; 95% CI 25.7%–70.2%). The median progression‐free and overall survivals were 4.2 (95% CI 2.9–4.8) and 7.2 (95% CI 5.1–18.4) months, respectively. Two PD‐L1‐expressing (≥1%) patients are alive following subsequent pembrolizumab immunotherapy (9.5%). Tumoral ASS1 deficiency enriched for p53 (64.7%) mutations, and numerically worse median overall survival as compared to ASS1‐proficient disease (10.2 months; n = 29). There was no apparent increase in KRAS mutations (35.3%) and PD‐L1 (<1%) expression (55.6%). Re‐expression of tumoral ASS1 was detected in one patient at progression (n = 1/3).

Conclusions

ADIPemCis was safe and highly active in patients with ASS1‐deficient non‐squamous NSCLC, however, survival was poor overall. ASS1 loss was co‐associated with p53 mutations. Therapies incorporating pegargiminase merit further evaluation in ASS1‐deficient and treatment‐refractory NSCLC.

Phase 1b study of pegylated arginine deiminase (ADI-PEG 20) plus Pembrolizumab in advanced solid cancers

Background

Pegylated arginine deiminase (ADI-PEG 20) is a metabolism-based strategy that depletes arginine, resulting in tumoral stress and cytotoxicity. Preclinically, ADI-PEG 20 modulates T-cell activity and enhances the therapeutic efficacy of programmed death-1 (PD-1) inhibition.

Methods

A phase 1b study, including a dose-escalation cohort and an expansion cohort, was undertaken to explore the effects of ADI-PEG 20 in combination with pembrolizumab, an anti-PD-1 antibody, for safety, pharmacodynamics, and response. CD3 levels and programmed death-ligand 1 (PD-L1) expression were assessed in paired biopsies collected prior to and after ADI-PEG 20 treatment but before pembrolizumab.

Results

Twenty-five patients, nine in the dose-escalation cohort and sixteen in the expansion cohort, were recruited. Treatment was feasible with adverse events consistent with those known for each agent, except for Grade 3/4 neutropenia which was higher than expected, occurring in 10/25 (40%) patients. Mean arginine levels were suppressed for 1-3 weeks, but increased gradually. CD3+ T cells increased in 10/12 (83.3%) subjects following ADI-PEG 20 treatment, including in three partial responders (p = .02). PD-L1 expression was low and increased in 3/10 (30%) of subjects. Partial responses occurred in 6/25 (24%) heavily pretreated patients, in both argininosuccinate synthetase 1 proficient and deficient subjects.

Conclusions

The immunometabolic combination was safe with the caveat that the incidence of neutropenia might be increased compared with either agent alone. ADI-PEG 20 treatment increased T cell infiltration in the low PD-L1 tumor microenvironment. The recommended phase 2 doses are 36 mg/m2 weekly for ADI-PEG 20 and 200 mg every 3 weeks for pembrolizumab.

Phase II trial of pegylated arginine deiminase in combination with gemcitabine and docetaxel for the treatment of soft tissue sarcoma

11508

Background: Soft tissue sarcoma (STS) is dependent on extracellular arginine as it often lacks expression of argininosuccinate synthase 1 (ASS1), the urea cycle enzyme needed to produce intracellular arginine. PEGylated arginine deiminase (ADI-PEG 20) is an extracellular arginine-degrading enzyme that causes ASS1 deficient tumors to enter the starvation state. Preclinical data demonstrated that addition of docetaxel (D) with ADI-PEG20 upregulates expression of the transporter for gemcitabine (G), overcoming transporter level resistance, and causing increased cell death. In vivo modeling demonstrated that the combination of ADI-PEG20 with G+D was superior to G+D alone. Therefore, we performed a phase 2 trial testing the addition of ADI-PEG20 to G+D. Methods: We performed an investigator-initiated, phase 2, multicenter, multi-arm clinical trial of ADI-PEG20 with G (90minute infusion)+D in STS, Ewing’s, osteosarcoma and small cell lung cancer. We are reporting Arm A, the STS arm. Eligible patients had STS that would be standardly treated with G+D that had progressed on at least one prior line of therapy with measurable disease by RECIST1.1 and had adequate organ function Based on a historic median PFS of 6.2 months for G+D, we targeted to enroll N = 75 patients in cohort A to detect a 2.8 month improvement with 80% power at a 5% alpha level. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), clinical benefit rate (CBR), safety, tolerability, cancer related mortality, and correlation with ASS1 expression by IHC. We evaluated PFS by Kaplan-Meier method and estimated overall response rate (ORR). Results: 75 patients were treated and deemed evaluable. The trial underwent two dose reductions by the data safety monitoring board due to prolonged neutropenia and thrombocytopenia preventing the use of day 8 G+D, consistent with preclinical mechanism of action data showing that ADI-PEG 20+D enhanced G uptake. Originally, the G dose was 900mg/m2 reduced first to 750mg/m2 then to 600mg/m2. D was dose reduced at the time of the second dose reduction from 75mg/m2 to 60mg/m2. ADI-PEG20 was given at a fixed intramuscular dose (36 mg/m2) weekly. The need for two dose reductions affected the PFS. The PFS/OS (months) were for the 600mg/m2 group (n = 31) was 6.0/N.D., leiomyosarcoma (LMS) (N = 33) 7.2/22.5, liposarcoma 5.1/17.4, and other (N = 36) 2.8/15.0. Responses were 8% complete (6/75) (3 LMS, 1 synovial and 2 angiosarcoma), 17% partial (13/75), and 43% stable disease (32/75), for an ORR of 25% (19/75) and CBR of 68% (51/75). There was a trend for ASS1 negative tumors to benefit more than ASS1 positive tumors. Conclusions: The combination of ADI-PEG20 with G+D can be safely and effectively given at a dose of 600mg/m2 G and 60mg/m2 D. Future randomized trials of ADI-PEG20 with G+D are planned. Clinical trial information: NCT03449901.

Development of an artificial intelligence-based assessment model for prediction of embryo viability using static images captured by optical light microscopy during IVF

STUDY QUESTION

Can an artificial intelligence (AI)-based model predict human embryo viability using images captured by optical light microscopy?

SUMMARY ANSWER

We have combined computer vision image processing methods and deep learning techniques to create the non-invasive Life Whisperer AI model for robust prediction of embryo viability, as measured by clinical pregnancy outcome, using single static images of Day 5 blastocysts obtained from standard optical light microscope systems.

WHAT IS KNOWN ALREADY

Embryo selection following IVF is a critical factor in determining the success of ensuing pregnancy. Traditional morphokinetic grading by trained embryologists can be subjective and variable, and other complementary techniques, such as time-lapse imaging, require costly equipment and have not reliably demonstrated predictive ability for the endpoint of clinical pregnancy. AI methods are being investigated as a promising means for improving embryo selection and predicting implantation and pregnancy outcomes.

STUDY DESIGN, SIZE, DURATION

These studies involved analysis of retrospectively collected data including standard optical light microscope images and clinical outcomes of 8886 embryos from 11 different IVF clinics, across three different countries, between 2011 and 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The AI-based model was trained using static two-dimensional optical light microscope images with known clinical pregnancy outcome as measured by fetal heartbeat to provide a confidence score for prediction of pregnancy. Predictive accuracy was determined by evaluating sensitivity, specificity and overall weighted accuracy, and was visualized using histograms of the distributions of predictions. Comparison to embryologists’ predictive accuracy was performed using a binary classification approach and a 5-band ranking comparison.

MAIN RESULTS AND THE ROLE OF CHANCE

The Life Whisperer AI model showed a sensitivity of 70.1% for viable embryos while maintaining a specificity of 60.5% for non-viable embryos across three independent blind test sets from different clinics. The weighted overall accuracy in each blind test set was >63%, with a combined accuracy of 64.3% across both viable and non-viable embryos, demonstrating model robustness and generalizability beyond the result expected from chance. Distributions of predictions showed clear separation of correctly and incorrectly classified embryos. Binary comparison of viable/non-viable embryo classification demonstrated an improvement of 24.7% over embryologists’ accuracy (P = 0.047, n = 2, Student’s t test), and 5-band ranking comparison demonstrated an improvement of 42.0% over embryologists (P = 0.028, n = 2, Student’s t test).

LIMITATIONS, REASONS FOR CAUTION

The AI model developed here is limited to analysis of Day 5 embryos; therefore, further evaluation or modification of the model is needed to incorporate information from different time points. The endpoint described is clinical pregnancy as measured by fetal heartbeat, and this does not indicate the probability of live birth. The current investigation was performed with retrospectively collected data, and hence it will be of importance to collect data prospectively to assess real-world use of the AI model.

WIDER IMPLICATIONS OF THE FINDINGS

These studies demonstrated an improved predictive ability for evaluation of embryo viability when compared with embryologists’ traditional morphokinetic grading methods. The superior accuracy of the Life Whisperer AI model could lead to improved pregnancy success rates in IVF when used in a clinical setting. It could also potentially assist in standardization of embryo selection methods across multiple clinical environments, while eliminating the need for complex time-lapse imaging equipment. Finally, the cloud-based software application used to apply the Life Whisperer AI model in clinical practice makes it broadly applicable and globally scalable to IVF clinics worldwide.

STUDY FUNDING/COMPETING INTEREST(S)

Life Whisperer Diagnostics, Pty Ltd is a wholly owned subsidiary of the parent company, Presagen Pty Ltd. Funding for the study was provided by Presagen with grant funding received from the South Australian Government: Research, Commercialisation and Startup Fund (RCSF). ‘In kind’ support and embryology expertise to guide algorithm development were provided by Ovation Fertility. J.M.M.H., D.P. and M.P. are co-owners of Life Whisperer and Presagen. Presagen has filed a provisional patent for the technology described in this manuscript (52985P pending). A.P.M. owns stock in Life Whisperer, and S.M.D., A.J., T.N. and A.P.M. are employees of Life Whisperer.

Phase I study of ADI-PEG20 plus low-dose cytarabine for the treatment of acute myeloid leukemia

Most acute myeloid leukemia (AML) cells are argininosuccinate synthetase‐deficient. Pegylated arginine deiminase (ADI‐PEG20) monotherapy depletes circulating arginine, thereby selectively inducing tumor cell death. ADI‐PEG20 was shown to induce complete responses in ~10% of relapsed/refractory or poor‐risk AML patients. We conducted a phase I, dose‐escalation study combining ADI‐PEG20 and low‐dose cytarabine (LDC) in AML patients. Patients received 20 mg LDC subcutaneously twice daily for 10 days every 28 days and ADI‐PEG20 at 18 or 36 mg/m² (dose levels 1 and 2) intramuscularly weekly. An expansion cohort for the maximal tolerated dose of ADI‐PEG20 was planned to further estimate the toxicity and preliminary response of this regimen. The primary endpoints were safety and tolerability. The secondary endpoints were time on treatment, overall survival (OS), overall response rate (ORR), and biomarkers (pharmacodynamics and immunogenicity detection). Twenty‐three patients were included in the study, and seventeen patients were in the expansion cohort (dose level 2). No patients developed dose‐limiting toxicities. The most common grade III/IV toxicities were thrombocytopenia (61%), anemia (52%), and neutropenia (30%). One had an allergic reaction to ADI‐PEG20. The ORR in 18 evaluable patients was 44.4%, with a median OS of 8.0 (4.5‐not reached) months. In seven treatment‐naïve patients, the ORR was 71.4% and the complete remission rate was 57.1%. The ADI‐PEG20 and LDC combination was well‐tolerated and resulted in an encouraging ORR. Further combination studies are warranted. (This trial was registered in ClinicalTrials.gov as a Ph1 Study of ADI‐PEG20 Plus Low‐Dose Cytarabine in Older Patients With AML, NCT02875093).

Prothrombin complex concentrate vs. fresh frozen plasma in adult patients undergoing heart surgery - a pilot randomised controlled trial (PROPHESY trial)

There is equipoise regarding the use of prothrombin complex concentrate vs. fresh frozen plasma in bleeding patients undergoing cardiac surgery. We performed a pilot randomised controlled trial to determine the recruitment rate for a large trial, comparing the impact of prothrombin complex concentrate vs. fresh frozen plasma on haemostasis (1 h and 24 h post-intervention), and assessing safety. Adult patients who developed bleeding within 24 h of cardiac surgery that required coagulation factor replacement were randomly allocated to receive prothrombin complex concentrate (15 IU.kg^-1 based on factor IX) or fresh frozen plasma (15 ml.kg^-1 ). If bleeding continued after the first administration of prothrombin complex concentrate or fresh frozen plasma administration, standard care was administered. From February 2019 to October 2019, 180 patients were screened, of which 134 (74.4% (95%CI 67-81%)) consented, 59 bled excessively and 50 were randomly allocated; 25 in each arm, recruitment rate 35% (95%CI 27-44%). There were 23 trial protocol deviations, 137 adverse events (75 prothrombin complex concentrate vs. 62 fresh frozen plasma) and 18 serious adverse events (5 prothrombin complex concentrate vs. 13 fresh frozen plasma). There was no increase in thromboembolic events with prothrombin complex concentrate. No patient withdrew from the study, four were lost to follow-up and two died. At 1 h after administration of the intervention there was a significant increase in fibrinogen, Factor V, Factor XII, Factor XIII, α₂ -antiplasmin and antithrombin levels in the fresh frozen plasma arm, while Factor II and Factor X were significantly higher in the prothrombin complex concentrate group. At 24 h, there were no significant differences in clotting factor levels. We conclude that recruitment to a larger study is feasible. Haemostatic tests have provided useful insight into the haemostatic changes following prothrombin complex concentrate or fresh frozen plasma administration. A definitive trial is needed to ascertain the benefits and safety for each.

Expansion Phase 1 Study of Pegargiminase Plus Pemetrexed and Cisplatin in Patients With Argininosuccinate Synthetase 1-Deficient Mesothelioma: Safety, Efficacy, and Resistance Mechanisms

INTRODUCTION

Pegargiminase (ADI-PEG 20; ADI) degrades arginine and potentiates pemetrexed (Pem) cytotoxicity in argininosuccinate synthetase 1 (ASS1)-deficient malignant pleural mesothelioma (MPM). We conducted a phase 1 dose-expansion study at the recommended phase 2 dose of ADI-PEG 20 with Pem and cisplatin (ADIPemCis), to further evaluate arginine-lowering therapy in ASS1-deficient MPM and explore the mechanisms of resistance.

METHODS

A total of 32 patients with ASS1-deficient MPM (11 epithelioid; 10 biphasic;11 sarcomatoid) who were chemonaive received weekly intramuscular pegargiminase (36 mg/m2) with Pem (500 mg/m2) and cisplatin (75 mg/m2) intravenously, every 3 weeks (six cycles maximum). Maintenance pegargiminase was permitted until disease progression or withdrawal. Safety, pharmacodynamics, immunogenicity, and efficacy were determined. Biopsies were performed in progressing patients to explore the mechanisms of resistance to pegargiminase.

RESULTS

The treatment was well tolerated. Most adverse events were of grade 1/2, whereas four nonhematologic grade 3/4 adverse events related to pegargiminase were reversible. Plasma arginine decreased whereas citrulline increased; this was maintained by 18 weeks of ADIPemCis therapy. The disease control rate in 31 assessed patients was 93.5% (n = 29 of 31; 95% confidence interval [CI]: 78.6%-99.2%), with a partial response rate of 35.5% (n = 11 of 31; 95% CI: 19.2%-54.6%). The median progression-free and overall survivals were 5.6 (95% CI: 4.0-6.0) and 10.1 (95% CI: 6.1-11.1) months, respectively. Progression biopsies on pegargiminase revealed a statistically significant influx of macrophages (n = 6; p = 0.0255) and patchy tumoral ASS1 reexpression (n = 2 of 6). In addition, we observed increased tumoral programmed death-ligand 1-an ADI-PEG 20 inducible gene-and the formation of CD3-positive T lymphocyte aggregates on disease progression (n = 2 of 5).

CONCLUSIONS

The dose expansion of ADIPemCis confirmed the high clinical activity and good tolerability in ASS1-deficient poor-prognosis mesothelioma, underpinning an ongoing phase 3 study (ClinicalTrials.govNCT02709512). Notably, resistance to pegargiminase correlated with marked macrophage recruitment and-along with the tumor immune microenvironment-warrants further study to optimize arginine deprivation for the treatment of mesothelioma.

Heparin resistance in COVID-19 patients in the intensive care unit

Patients with COVID-19 have a coagulopathy and high thrombotic risk. In a cohort of 69 intensive care unit (ICU) patients we investigated for evidence of heparin resistance in those that have received therapeutic anticoagulation. 15 of the patients have received therapeutic anticoagulation with either unfractionated heparin (UFH) or low molecular weight heparin (LMWH), of which full information was available on 14 patients. Heparin resistance to UFH was documented in 8/10 (80%) patients and sub-optimal peak anti-Xa following therapeutic LMWH in 5/5 (100%) patients where this was measured (some patients received both anticoagulants sequentially). Spiking plasma from 12 COVID-19 ICU patient samples demonstrated decreased in-vitro recovery of anti-Xa compared to normal pooled plasma. In conclusion, we have found evidence of heparin resistance in critically unwell COVID-19 patients. Further studies investigating this are required to determine the optimal thromboprophylaxis in COVID-19 and management of thrombotic episodes.

Meta-analysis of the impact of postoperative infective complications on oncological outcomes in colorectal cancer surgery

BACKGROUND

Cancer outcomes are complex, involving prevention, early detection and optimal multidisciplinary care. Postoperative infection and surgical site-infection (SSI) are not only uncomfortable for patients and costly, but may also be associated with poor oncological outcomes. A meta-analysis was undertaken to assess the oncological effects of SSI in patients with colorectal cancer.

METHODS

An ethically approved PROSPERO-registered meta-analysis was conducted following PRISMA guidelines. PubMed and Scopus databases were searched for studies published between 2007 and 2017 reporting the effects of postoperative infective complications on oncological survival in colorectal cancer. Results were separated into those for SSI and those concerning anastomotic leakage. Articles with a Methodological Index for Non-Randomized Studies score of at least 18 were included. Hazard ratios (HRs) with 95 per cent confidence intervals were computed for risk factors using an observed to expected and variance fixed-effect model.

RESULTS

Of 5027 articles were reviewed, 43 met the inclusion criteria, with a total of 154 981 patients. Infective complications had significant negative effects on overall survival (HR 1·37, 95 per cent c.i. 1·28 to 1·46) and cancer-specific survival (HR 2·58, 2·15 to 3·10). Anastomotic leakage occurred in 7·4 per cent and had a significant negative impact on disease-free survival (HR 1·14, 1·09 to 1·20), overall survival (HR 1·34, 1·28 to 1·39), cancer-specific survival (HR 1·43, 1·31 to 1·55), local recurrence (HR 1·18, 1·06 to 1·32) and overall recurrence (HR 1·46, 1·27 to 1·68).

CONCLUSION

This meta-analysis identified a significant negative impact of postoperative infective complications on overall and cancer-specific survival in patients undergoing colorectal surgery.

Comparing abundance distributions and range maps in spatial conservation planning for migratory species

Most spatial conservation planning for wide-ranging or migratory species is constrained by poor knowledge of species' spatiotemporal dynamics and is only based on static species' ranges. However, species have substantial variation in abundance across their range and migratory species have important spatiotemporal population dynamics. With growing ecological data and advancing analytics, both of these can be estimated and incorporated into spatial conservation planning. However, there is limited information on the degree to which including this information affects conservation planning. We compared the performance of systematic conservation prioritizations for different scenarios based on varying the input species' distributions by ecological metric (abundance distributions versus range maps) and temporal sampling resolution (weekly, monthly, or quarterly). We used the example of a community of 41 species of migratory shorebirds that breed in North America, and we used eBird data to produce weekly estimates of species' abundances and ranges. Abundance distributions at a monthly or weekly resolution led to prioritizations that most efficiently protected species throughout the full annual cycle. Conversely, spatial prioritizations based on species' ranges required more sites and left most species insufficiently protected for at least part of their annual cycle. Prioritizations with only quarterly species ranges were very inefficient as they needed to target 40% of species' ranges to include 10% of populations. We highlight the high value of abundance information for spatial conservation planning, which leads to more efficient and effective spatial prioritization for conservation. Overall, we provide evidence that spatial conservation planning for wide-ranging migratory species is most robust and efficient when informed by species' abundance information from the full annual cycle.

New search for mirror neutron regeneration

The possibility of relatively fast neutron oscillations into a mirror neutron state is not excluded experimentally when a mirror magnetic field is considered. Direct searches for the disappearance of neutrons into mirror neutrons in a controlled magnetic field have previously been performed using ultracold neutrons, with some anomalous results reported. We describe a technique using cold neutrons to perform a disappearance and regeneration search, which would allow us to unambiguously identify a possible oscillation signal. An experiment using the existing General Purpose-Small Angle Neutron Scattering instrument at the High Flux Isotope Reactor at Oak Ridge National Laboratory will have the sensitivity to fully explore the parameter space of prior ultracold neutron searches and confirm or refute previous claims of observation. This instrument can also conclusively test the validity of recently suggested oscillation-based explanations for the neutron lifetime anomaly.

Phase III randomized study of second line ADI-PEG 20 plus best supportive care versus placebo plus best supportive care in patients with advanced hepatocellular carcinoma

Background

Arginine depletion is a putative target in hepatocellular carcinoma (HCC). HCC often lacks argininosuccinate synthetase, a citrulline to arginine-repleting enzyme. ADI-PEG 20 is a cloned arginine degrading enzyme-arginine deiminase-conjugated with polyethylene glycol. The goal of this study was to evaluate this agent as a potential novel therapeutic for HCC after first line systemic therapy.

Methods and patients

Patients with histologically proven advanced HCC and Child-Pugh up to B7 with prior systemic therapy, were randomized 2 : 1 to ADI-PEG 20 18 mg/m2 versus placebo intramuscular injection weekly. The primary end point was overall survival (OS), with 93% power to detect a 4-5.6 months increase in median OS (one-sided α = 0.025). Secondary end points included progression-free survival, safety, and arginine correlatives.

Results

A total of 635 patients were enrolled: median age 61, 82% male, 60% Asian, 52% hepatitis B, 26% hepatitis C, 76% stage IV, 91% Child-Pugh A, 70% progressed on sorafenib and 16% were intolerant. Median OS was 7.8 months for ADI-PEG 20 versus 7.4 for placebo (P = 0.88, HR = 1.02) and median progression-free survival 2.6 months versus 2.6 (P = 0.07, HR = 1.17). Grade 3 fatigue and decreased appetite occurred in <5% of patients. Two patients on ADI-PEG 20 had ≥grade 3 anaphylactic reaction. Death rate within 30 days of end of treatment was 15.2% on ADI-PEG 20 versus 10.4% on placebo, none related to therapy. Post hoc analyses of arginine assessment at 4, 8, 12 and 16 weeks, demonstrated a trend of improved OS for those with more prolonged arginine depletion.

Conclusion

ADI-PEG 20 monotherapy did not demonstrate an OS benefit in second line setting for HCC. It was well tolerated. Strategies to enhance prolonged arginine depletion and synergize the effect of ADI-PEG 20 are underway.

Clinical Trial number

www.clinicaltrials.gov (NCT 01287585).

Retrospective study of patients radiation dose during cardiac catheterization procedures

OBJECTIVE

Cardiac catheterization procedures provide tremendous benefits to modern healthcare and the benefit derived by the patient should far outweigh the radiation risk associated with a properly optimized procedure. With increasing utilization of such procedures, there is growing concern regarding the magnitude and variations of dose to patients associated with procedure complexity and techniques parameters. Therefore, this study investigated radiation dose to patients from six cardiac catheterization procedures at our facility and suggest possible initial dose values for benchmark for patient radiation dose from these procedures. This initial benchmark data will be used for clinical radiation dose management which is essential for assessing the impact of any quality improvement initiatives in the cardiac catheterization laboratory.

METHODS

We retrospectively analyzed the dose parameters of 1000 patients who underwent various cardiac catheterization procedures: left heart catheterization (LH), percutaneous coronary intervention (PCI), complex PCI, LH with complex PCI, LH with PCI and cardiac resynchronization therapy (CRT) pacemaker in our cardiac catheterization laboratories. Patient's clinical radiation dose data [kerma-area-product (KAP) and air-kerma at the interventional reference point (Ka,r)] and technique parameters (fluoroscopy time, tube potential, current, pulse width and number of cine images) along with demographic information (age, height and weight) were collected from the hospital's RIS (Synapse), Sensis/Syngo Dynamics and Siemens Sensis Stats Manager electronic database. Statistical analysis was performed with the IBM SPSS Modeler v. 18.1 software.

RESULTS

The overall patient median age was 67.0 (range: 26.0-97.0) years and the median body mass index (BMI) was 28.8 (range: 15.9-61.7) kg/m2 . The median KAP for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 44.4 (4.1-203.2), 80.2 (18.9-208.5), 83.7 (48.0-246.1), 113.8 (60.9-284.5), 91.7 (6.0-426.0) and 51.1 (7.0-175.9) Gy-cm2 . The median Ka,r for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 701.0 (35.3-3794.0), 1384.7 (291.7-4021.8), 1607.0 (883.5-4448.3), 2260.2 (867.4-5311.9), 1589.3 (100.2-7237.4) and 463.8 (67.7-1695.9) mGy respectively.

CONCLUSION

We have analyzed patient radiation doses from six commonly used procedures in our cardiac catheterization laboratories and suggested possible initial values for benchmark from these procedures for the fluoroscopy time, KAP and air-kerma at the interventional reference point based on our current practices. Our data compare well with published values reported in the literature by investigators who have also studied patient doses and established benchmark dose levels for their facilities. Procedure-specific benchmark dose data for various groups of patients can provide the motivation for monitoring practices to promote improvements in patient radiation dose optimization in the cardiac catheterization laboratories.

ADVANCES IN KNOWLEDGE

We have investigated local patients' radiation doses and established benchmark radiation data which are essential for assessing the impact of any quality improvement initiatives for radiation dose optimization.

A Phase I Study of Pegylated Arginine Deiminase (Pegargiminase), Cisplatin, and Pemetrexed in Argininosuccinate Synthetase 1-Deficient Recurrent High-grade Glioma

PURPOSE

Patients with recurrent high-grade gliomas (HGG) are usually managed with alkylating chemotherapy ± bevacizumab. However, prognosis remains very poor. Preclinically, we showed that HGGs are a target for arginine depletion with pegargiminase (ADI-PEG20) due to epimutations of argininosuccinate synthetase (ASS1) and/or argininosuccinate lyase (ASL). Moreover, ADI-PEG20 disrupts pyrimidine pools in ASS1-deficient HGGs, thereby impacting sensitivity to the antifolate, pemetrexed.

PATIENTS AND METHODS

We expanded a phase I trial of ADI-PEG20 with pemetrexed and cisplatin (ADIPEMCIS) to patients with ASS1-deficient recurrent HGGs (NCT02029690). Patients were enrolled (01/16-06/17) to receive weekly ADI-PEG20 36 mg/m² intramuscularly plus pemetrexed 500 mg/m² and cisplatin 75 mg/m² intravenously once every 3 weeks for up to 6 cycles. Patients with disease control were allowed ADI-PEG20 maintenance. The primary endpoints were safety, tolerability, and preliminary estimates of efficacy.

RESULTS

Ten ASS1-deficient heavily pretreated patients were treated with ADIPEMCIS therapy. Treatment was well tolerated with the majority of adverse events being Common Terminology Criteria for Adverse Events v4.03 grade 1-2. The best overall response was stable disease in 8 patients (80%). Plasma arginine was suppressed significantly below baseline with a reciprocal increase in citrulline during the sampling period. The anti-ADI-PEG20 antibody titer rose during the first 4 weeks of treatment before reaching a plateau. Median progression-free survival (PFS) was 5.2 months (95% confidence interval (CI), 2.5-20.8) and overall survival was 6.3 months (95% CI, 1.8-9.7).

CONCLUSIONS

In this recurrent HGG study, ADIPEMCIS was well tolerated and compares favorably to historical controls. Additional trials of ADI-PEG20 in HGG are planned.

A phase II study of ADI-PEG 20 and FOLFOX6 in patients (pts) with advanced hepatocellular carcinoma (HCC)

TPS477

Background: Arginine depletion interferes with pyrimidine metabolism as well as DNA damage repair pathways, and preclinical data indicate that pairing pegylated arginine deiminase (ADI-PEG 20) with fluoropyrimidines or platinum enhances cytotoxicity in vitro and in vivo in HCC models. A prior phase 1 study of FOLFOX6 and ADI-PEG 20 established the safety and recommended phase 2 dose of the combination in pts with advanced gastrointestinal tumors (Harding et al. CCP 2018). For 23 treatment-refractory HCC pts who were treated at the recommended phase 2 dose on an expansion cohort of the phase 1, the objective response rate (ORR) was 21% (95% CI 7.5-43.7) and median progression-free survival (PFS) was 7.3 months. These data were favorable when compared to historic data for FOLFOX alone where the ORR was ~8% and PFS was 2.93 months and suggest greater clinical activity of the combination (Qin et al. JCO 2013). Prospective confirmation of these results is required. Methods: This is an international, multicenter, single-arm, open-label phase 2 trial of ADI-PEG 20 and FOLFOX6 for advanced HCC pts with Child-Pugh A liver function who progressed on ≥ 2 prior lines of prior systemic therapy (NCT02102022). The primary objective is to define the ORR by RECIST 1.1 as assessed by blinded independent central review. Secondary objectives include determination of safety, disease control rate (DCR), duration of response (DOR), PFS, overall survival (OS), serum arginine, citrulline and anti-ADI-PEG 20 levels over 24 weeks, and alpha-fetoprotein response. Eligible pts receive intravenous FOLFOX6 biweekly at standard doses and ADI-PEG 20 intramuscularly weekly at 36 mg/m.2 Cross-sectional imaging will be completed every 8 weeks until progression of disease. Based on a two-sided exact test of a one-sample proportion with an alpha of 0.05, under a presumed ORR of 22%, there is 80% power to yield 95% confidence interval of 15-26%, which will require 46 objective responses in 225 subjects. Futility will be assessed three times during the study based on having ORR data available for 56, 110, and 166 patients. This Phase 2 will be stopped for futility if the conditional power drops below 20% at any of these time points. Clinical trial information: NCT02102022.

An evaluation of methods for the isolation of nontuberculous mycobacteria from patients with cystic fibrosis, bronchiectasis and patients assessed for lung transplantation

BACKGROUND

RGM medium is an agar-based, selective culture medium designed for the isolation of nontuberculous mycobacteria (NTM) from the sputum of patients with cystic fibrosis (CF). We evaluated RGM medium for the detection of NTM in patients with CF (405 samples), bronchiectasis (323 samples) and other lung diseases necessitating lung transplantation (274 samples).

METHODS

In total, 1002 respiratory samples from 676 patients were included in the study. Direct culture on RGM medium, with incubation at two temperatures (30 °C and 37 °C), was compared with conventional culture of decontaminated samples for acid-fast bacilli (AFB) using both a solid medium (Löwenstein-Jensen medium) and a liquid medium (the Mycobacterial Growth Indicator Tube; MGIT).

RESULTS

For all three patient groups, significantly more isolates of NTM were recovered using RGM medium incubated at 30 °C than by any other method (sensitivity: 94.6% vs. 22.4% for conventional AFB culture; P < 0.0001). Significantly more isolates of Mycobacterium abscessus complex were isolated on RGM at 30 °C than by AFB culture (sensitivity: 96.1% vs. 58.8%; P < 0.0001). The recovery of Mycobacterium avium complex was also greater using RGM medium at 30 °C compared to AFB culture (sensitivity: 83% vs. 70.2%), although this difference was not statistically significant and a combination of methods was necessary for optimal recovery (P = 0.21).

CONCLUSIONS

In the largest study of RGM medium to date, we reaffirm its utility for isolation of NTM from patients with CF. Furthermore; we show that it also provides an effective tool for culture of respiratory samples from patients with bronchiectasis and other lung diseases.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Abstract B33: Expansion study of pegylated arginine deiminase (ADI-PEG20), pemetrexed, and cisplatin in patients with ASS1-deficient non-squamous non-small cell lung cancer (TRAP)

Background: Loss of the metabolic tumor suppressor argininosuccinate synthetase 1 (ASS1) sensitizes non-squamous non-small cell lung cancer (NSCLC) cells to arginine deprivation with pegylated arginine deiminase (ADI-PEG20), which also disrupts thymidine pools and potentiates pemetrexed (Pem) cytotoxicity. In the phase I dose-escalation TRAP study (NCT02029690) we showed that ADI-PEG20 with first-line PEM and cisplatin (Cis) chemotherapy (ADIPemCis) produced a 100% disease control rate (DCR) (n = 9) of ASS1-deficient thoracic cancers, with no additional toxicity (Beddowes et al., 2017). Here, we present the TRAP expansion cohort experience in non-squamous NSCLC.

Methods: Good-performance (ECOG 0-1) NSCLC patients (pts) with nonresectable disease were enrolled in a phase I TRAP expansion cohort at the maximum tolerated dose (MTD) of ADIPemCis, using tumoral ASS1 loss as a selection biomarker. Pem (500mg/m2) and Cis (75mg/m2) were given every 3 weeks with weekly IM ADI-PEG20 (36mg/m2) for a maximum of 4 cycles with maintenance ADI-PEG20 or Pem in responding pts. Primary endpoint was tumor response rate (RECIST 1.1), with secondary endpoints including progression-free survival (PFS), overall survival (OS), and toxicity. We measured plasma arginine and citrulline concentrations, ADI-PEG20 antibodies, early molecular responses by 18-FLT-PET/CT, and biopsied pts on progression to explore resistance mechanisms.

Results: 21 ASS1-deficient non-squamous NSCLC pts (median age 60) were enrolled out of 70 screened pts; 14% (3/21) had stable brain metastases at entry. Plasma arginine decreased with a reciprocal increase in plasma citrulline. The partial response rate was 48% (n=10/21) with a DCR of 85.7% (n=18/21). Median PFS was 2.6 months and median OS was 5.3 months. 23.8% (n=5/21) pts experienced grade 3/4 treatment-related toxicities, the most common being non-febrile neutropenia (14.3%). A partial metabolic response was detected in 57.1% (n=4/7) pts by 24 hrs of arginine deprivation using 18-FLT-PET/CT with EORTC response criteria. Upregulation of ASS1 expression was observed in 1/3 biopsies on progression.

Conclusions: The ADIPemCis regimen is active in ASS1-deficient non-squamous NSCLC pts with a higher than expected response rate. However, the short survival (PFS and OS) compared with ASS1-agnostic historical controls indicates that ASS1 loss selects for a biologically more aggressive phenotype of NSCLC. Further studies are warranted exploring rationale combinations with ADIPemCis in patients with ASS1-deficient non-squamous NSCLC.

Citation Format: Melissa Phillips, Teresa Szyszko, Peter Hall, Sukaina Rashid, Ramsay Khadeir, Louise Lim, Jeremy Steele, John Conibear, Paula Wells, Stephen Ellis, Xiaoxing Feng, Jim Thomson, Amanda Johnston, Bor-Wen Wu, John Bomalaski, Simon Pacey, Gary Cook, Peter Szlosarek. Expansion study of pegylated arginine deiminase (ADI-PEG20), pemetrexed, and cisplatin in patients with ASS1-deficient non-squamous non-small cell lung cancer (TRAP) [abstract]. In: Proceedings of the Fifth AACR-IASLC International Joint Conference: Lung Cancer Translational Science from the Bench to the Clinic; Jan 8-11, 2018; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(17_Suppl):Abstract nr B33.