Defining the spatial distribution of extracellular adenosine revealed a myeloid-dependent immunosuppressive microenvironment in pancreatic ductal adenocarcinoma

BACKGROUND

The prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. It has been suggested that the adenosine pathway contributes to the ability of PDAC to evade the immune system and hence, its resistance to immuno-oncology therapies (IOT), by generating extracellular adenosine (eAdo).

METHODS

Using genetically engineered allograft models of PDAC in syngeneic mice with defined and different immune infiltration and response to IOT and autochthonous tumors in KPC mice we investigated the impact of the adenosine pathway on the PDAC tumor microenvironment (TME). Flow cytometry and imaging mass cytometry (IMC) were used to characterize the subpopulation frequency and spatial distribution of tumor-infiltrating immune cells. Mass spectrometry imaging (MSI) was used to visualize adenosine compartmentalization in the PDAC tumors. RNA sequencing was used to evaluate the influence of the adenosine pathway on the shaping of the immune milieu and correlate our findings to published data sets in human PDAC.

RESULTS

We demonstrated high expression of adenosine pathway components in tumor-infiltrating immune cells (particularly myeloid populations) in the murine models. MSI demonstrated that extracellular adenosine distribution is heterogeneous in tumors, with high concentrations in peri-necrotic, hypoxic regions, associated with rich myeloid infiltration, demonstrated using IMC. Protumorigenic M2 macrophages express high levels of the Adora2a receptor; particularly in the IOT resistant model. Blocking the in vivo formation and function of eAdo (Adoi), using a combination of anti-CD73 antibody and an Adora2a inhibitor slowed tumor growth and reduced metastatic burden. Additionally, blocking the adenosine pathway improved the efficacy of combinations of cytotoxic agents or immunotherapy. Adoi remodeled the TME, by reducing the infiltration of M2 macrophages and regulatory T cells. RNA sequencing analysis showed that genes related to immune modulation, hypoxia and tumor stroma were downregulated following Adoi and a specific adenosine signature derived from this is associated with a poorer prognosis in patients with PDAC.

CONCLUSIONS

The formation of eAdo promotes the development of the immunosuppressive TME in PDAC, contributing to its resistance to conventional and novel therapies. Therefore, inhibition of the adenosine pathway may represent a strategy to modulate the PDAC immune milieu and improve therapy response in patients with PDAC.

Abstract 6103: Reshaping the myeloid-dependent pro-tumorigenic microenvironment in PDAC by targeting the extracellular adenosine pathway: A therapeutic opportunity

The prognosis for patients with pancreatic adenocarcinoma (PDAC) remains extremely poor. PDAC is resistant to both conventional therapies and emerging immunotherapies (IOT), apart from tumors with mismatch repair deficiency. This may be explained in part by its low tumor mutational burden (TMB) but also by its immunosuppressive tumor microenvironment (TME). It has been suggested that CD73, a member of the adenosine pathway, expressed on cancer cells contributes to immune escape and resistance to cytotoxic/radiotherapy treatment. The adenosine pathway converts the immune activator ATP, released by dying cells during cell turnover or after treatment, to extracellular Adenosine (eAdo), which is immunosuppressive.

Using syngeneic, in vivo models by s.c. implantation of KPC-derived cell lines (courtesy of Ben Stanger, UPenn) with differential immune infiltration and response to IOT [resistant (IOTResi) or responsive (IOTResp)], we showed by flow cytometry that the adenosine pathway is enriched in the tumor-infiltrating immune cells (in particular myeloid populations) which co-express CD39 and CD73, enabling the formation of eAdo. Mass Spec Imaging (MSI) revealed that adenosine distribution is heterogeneous in the tumors with high concentrations in the hypoxic margins that surround necrotic areas. Subpopulations of myeloid cells infiltrating the lesions are a target for eAdo, expressing high levels of adenosine receptor Adora2a. We discovered that pro-tumorigenic M2 macrophages have the highest expression of the receptor and significantly higher in the IOTResi model. Blocking the in vivo formation and function of eAdo in IOTResi tumors, using a combination of anti-CD73 antibody (2C5, murine IgG1-Fc) and an inhibitor of Adora2a (AZD4635) reduced the presence of eAdo, slowed tumor growth and reduced the lung metastatic burden. The combination remodeled the TME, reducing the infiltration by M2 macrophages, particularly those that are PD-L1 positive and diminished the frequency of infiltrating Tregs. Bulk RNAseq analysis demonstrated a profound dependency of the TME on the presence of eAdo. Genes related to cytokine/chemokine signaling, immunosuppression/inflammation, hypoxia, metastasis and collagen production are strongly downregulated following administration of anti-CD73Ab/Adora2ai. In addition, blocking the adenosine pathway improved the efficacy of combinations of cytotoxics (gemcitabine/ATR inhibitor) and immunotherapy (aCD40/anti-PDL1Ab).

The formation of eAdo appears to be a factor in the development of the immunosuppressive TME in PDAC, contributing to its resistance to conventional and novel therapies. Therefore, inhibition of the adenosine pathway using a CD73Ab and an Adora2ai may represent a strategy to modulate the PDAC stroma and improve therapy response in patients with PDAC.

Citation Format: Vincenzo Graziano, Andreas Dannhorn, Kate Williamson, Heather Hulme, Hannah Buckley, Sheng Y. Lee, Sabita Islam, James E. Thaventhiran, Richard Goodwin, Rebecca Brais, Simon J. Dovedi, Alwin Schuller, Jim Eyles, Duncan I. Jodrell. Reshaping the myeloid-dependent pro-tumorigenic microenvironment in PDAC by targeting the extracellular adenosine pathway: A therapeutic opportunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6103.

In the eye of the storm: impact of COVID-19 pandemic on admission patterns to paediatric intensive care units in the UK and Eire

BACKGROUND

The coronavirus disease-19 (COVID-19) pandemic had a relatively minimal direct impact on critical illness in children compared to adults. However, children and paediatric intensive care units (PICUs) were affected indirectly. We analysed the impact of the pandemic on PICU admission patterns and patient characteristics in the UK and Ireland.

METHODS

We performed a retrospective cohort study of all admissions to PICUs in children < 18 years during Jan-Dec 2020, using data collected from 32 PICUs via a central database (PICANet). Admission patterns, case-mix, resource use, and outcomes were compared with the four preceding years (2016-2019) based on the date of admission.

RESULTS

There were 16,941 admissions in 2020 compared to an annual average of 20,643 (range 20,340-20,868) from 2016 to 2019. During 2020, there was a reduction in all PICU admissions (18%), unplanned admissions (20%), planned admissions (15%), and bed days (25%). There was a 41% reduction in respiratory admissions, and a 60% reduction in children admitted with bronchiolitis but an 84% increase in admissions for diabetic ketoacidosis during 2020 compared to the previous years. There were 420 admissions (2.4%) with either PIMS-TS or COVID-19 during 2020. Age and sex adjusted prevalence of unplanned PICU admission reduced from 79.7 (2016-2019) to 63.1 per 100,000 in 2020. Median probability of death [1.2 (0.5-3.4) vs. 1.2 (0.5-3.4) %], length of stay [2.3 (1.0-5.5) vs. 2.4 (1.0-5.7) days] and mortality rates [3.4 vs. 3.6%, (risk-adjusted OR 1.00 [0.91-1.11, p = 0.93])] were similar between 2016-2019 and 2020. There were 106 fewer in-PICU deaths in 2020 (n = 605) compared with 2016-2019 (n = 711).

CONCLUSIONS

The use of a high-quality international database allowed robust comparisons between admission data prior to and during the COVID-19 pandemic. A significant reduction in prevalence of unplanned admissions, respiratory diseases, and fewer child deaths in PICU observed may be related to the targeted COVID-19 public health interventions during the pandemic. However, analysis of wider and longer-term societal impact of the pandemic and public health interventions on physical and mental health of children is required.

Epidemiology of Cardiopulmonary Resuscitation in Critically Ill Children Admitted to Pediatric Intensive Care Units Across England: A Multicenter Retrospective Cohort Study

Background Cardiopulmonary arrests are a major contributor to mortality and morbidity in pediatric intensive care units (PICUs). Understanding the epidemiology and risk factors for CPR may inform national quality improvement initiatives. Methods and Results A retrospective cohort analysis using prospectively collected data from the Paediatric Intensive Care Audit Network database. The Paediatric Intensive Care Audit Network contains data on all PICU admissions in the United Kingdom. We identified children who received cardiopulmonary resuscitation (CPR) in 23 PICUs in England (2013-2017). Incidence rates of CPR and associated factors were analyzed. Logistic regression was used to estimate the size and precision of associations. Cumulative incidence of CPR was 2.2% for 68 114 admissions over 5 years with an incidence rate of 4.9 episodes/1000 bed days. Cardiovascular diagnosis (odds ratio [OR], 2.30; 95% CI, 2.02-2.61), age <1 year (OR, 1.84; 95% CI, 1.65-2.04), the Paediatric Index of Mortality 2 score on admission (OR, 1.045; 95% CI, 1.042-1.047) and longer length of stay (OR, 1.013; 95% CI, 1.012-1.014) were associated with increased odds of receiving CPR. We also found a higher risk of CPR associated with a history of preadmission cardiac arrest (OR, 20.69; [95% CI, 18.16-23.58) and for children with a cardiac condition admitted to a noncardiac PICU (OR, 2.75; 95% CI, 1.91-3.98). Children from Black (OR, 1.68; 95% CI, 1.36-2.07) and Asian (OR, 1.49; 95% CI, 1.28-1.74) racial/ethnic backgrounds were at higher risk of receiving CPR in PICU than White children. Conclusions Data from this first multicenter study from England provides a foundation for further research and evidence for benchmarking and quality improvement for prevention of cardiac arrests in PICU.

Trial of remote continuous versus intermittent NEWS monitoring after major surgery (TRaCINg): a feasibility randomised controlled trial

BACKGROUND

Despite medical advances, major surgery remains high risk with up to 44% of patients experiencing postoperative complications. Early recognition of postoperative complications is crucial in reducing morbidity and preventing long-term disability. The current standard of care is intermittent manual vital signs monitoring, but new wearable remote monitors offer the benefits of continuous vital signs monitoring without limiting the patient's mobility. The aim of this study was to evaluate the feasibility, acceptability and clinical outcomes of continuous remote monitoring after major surgery.

METHODS

The study was a randomised, controlled, unblinded, parallel group, feasibility trial. Adult patients undergoing elective major surgery were randomly assigned to receive continuous remote monitoring and normal National Early Warning Score (NEWS) monitoring (intervention group) or normal NEWS monitoring alone (control group). Continuous remote monitoring was achieved using the SensiumVitals® wireless patch which is worn on the patient's chest and monitors heart rate, respiratory rate and temperature continuously, and alerts the nurse when there is deviation from pre-set physiological norms. Feasibility was assessed by evaluating recruitment rate, adherence to protocol and randomisation and the amount of missing data. Clinical outcomes included time to antibiotics in cases of sepsis, length of hospital stay, number of critical care admissions and rate of hospital readmission within 30 days of discharge.

RESULTS

One hundred and thirty-six patients were randomised between October 2018 and April 2019: 67 to the control group and 69 to the intervention group. Recruitment was completed prior to the 12 month target with a high rate of eligibility and consent. Missing data was limited only to questionnaire responses; no participants were lost to follow-up and only one participant was withdrawn due to loss of capacity. The number of patients classed as 'drop-out' due to design (8.1%) were less than anticipated, and there were no participants who crossed over into the alternative trial allocation group. Seventeen participants in the intervention group (28%) did not adhere to the monitoring protocol. No formal comparisons between arms was undertaken; however, participants had fewer unplanned critical care admissions (1 versus 5) and had a shorter average length of hospital stay (11.6 days (95% confidence interval 9.5-13.7 days) versus 16.2 days (95% confidence interval 11.3-21.2 days)) in the continuous vital signs monitoring group. The time taken to receive antibiotics in cases of sepsis was similar in both arms. A cost-utility analysis indicated that the remote monitoring system was cost-saving when compared to standard NEWS monitoring alone.

CONCLUSIONS

It is feasible to perform a large-scale randomised controlled trial of continuous remote monitoring after major surgery. Progression to a definitive multicentre randomised controlled trial would be appropriate, taking consideration of factors, such as patient adherence, that might mask the potential benefit of additional monitoring.

TRIAL REGISTRATION

ISRCTN registry with study ID ISRCTN16601772 . Registered 30 August 2017.

Characterisation of baseline microbiological and host factors in an inception cohort of people with surgical wounds healing by secondary intention reveals circulating IL-6 levels as a potential predictive biomarker of healing

Background: More than 2 million people per year are treated for surgical wounds in the UK.  Over a quarter of these wounds are estimated to heal by secondary intention (from the "bottom up") resulting in further complications and requiring increased healthcare resources. Identification of microbiological or host biomarkers that can predict healing outcomes may help to optimize the management of surgical wounds healing by secondary intention. However, the microbial and host factor heterogeneity amongst this diverse population is completely unexplored. Methods: We demonstrate feasibility of determining presence and levels of wound microbes and systemic host factors in an inception cohort of 54 people presenting with surgical wounds healing by secondary intention, who were subsequently followed-up for a period of 12-21 months. We present descriptive statistics for plasma levels of inflammatory, angiogenic cytokines and microRNAs, and we identify a range of wound colonizing microbes. We tentatively explore association with healing aiming to generate hypotheses for future research. Results: We report a potential correlation between poor healing outcomes and elevated interleukin (IL)-6 plasma levels at presentation (ρ=0.13) which requires confirmation.   Conclusions: This study demonstrates the degree of biological heterogeneity amongst people with surgical wounds healing by secondary intention and proves the feasibility of embedding a biomarker discovery study in a cohort study in surgical wounds. Our results are essential for designing large biomarker discovery studies to further investigate the potential validity of circulating IL-6 or other factors as novel predictive biomarkers of healing for surgical wounds healing by secondary intention.

The epidemiology, management and impact of surgical wounds healing by secondary intention: a research programme including the SWHSI feasibility RCT

Background

Most surgical incisions heal by primary intention (i.e. wound edges are apposed with sutures, clips or glue); however, some heal by secondary intention (i.e. the wound is left open and heals by formation of granulation tissue). There is, however, a lack of evidence regarding the epidemiology, management and impact on patients’ quality of life of these surgical wounds healing by secondary intention, resulting in uncertainty regarding effective treatments and difficulty in planning care and research.

Objectives

To derive a better understanding of the nature, extent, costs, impact and outcomes of surgical wounds healing by secondary intention, effective treatments, and the value and nature of further research.

Design

Cross-sectional survey; inception cohort; cost-effectiveness and value of implementation analyses; qualitative interviews; and pilot, feasibility randomised controlled trial.

Setting

Acute and community care settings in Leeds and Hull, Yorkshire, UK.

Participants

Adults (or for qualitative interviews, patients or practitioners) with previous experience of a surgical wound healing by secondary intention. Inclusion criteria varied between the individual workstreams.

Interventions

The pilot, feasibility randomised controlled trial compared negative-pressure wound therapy – a device applying a controlled vacuum to a wound via a dressing – with usual care (no negative-pressure wound therapy).

Results

Survey data estimated that treated surgical wounds healing by secondary intention have a point prevalence of 4.1 per 10,000 population (95% confidence interval 3.5 to 4.7 per 10,000 population). Surgical wounds healing by secondary intention most frequently occurred following colorectal surgery (n = 80, 42.8% cross-sectional survey; n = 136, 39.7% inception cohort) and were often planned before surgery (n = 89, 47.6% cross-sectional survey; n = 236, 60.1% inception cohort). Wound care was frequently delivered in community settings (n = 109, 58.3%) and most patients (n = 184, 98.4%) received active wound treatment. Cohort data identified hydrofibre dressings (n = 259, 65.9%) as the most common treatment, although 29.3% (n = 115) of participants used negative-pressure wound therapy at some time during the study. Surgical wounds healing by secondary intention occurred in 81.4% (n = 320) of participants at a median of 86 days (95% confidence interval 75 to 103 days). Baseline wound area (p ≤ 0.01), surgical wound contamination (determined during surgery; p = 0.04) and wound infection at any time (p ≤ 0.01) (i.e. at baseline or postoperatively) were found to be predictors of prolonged healing. Econometric models, using observational, cohort study data, identified that, with little uncertainty, negative-pressure wound therapy treatment is more costly and less effective than standard dressing treatment for the healing of open surgical wounds. Model A (ordinary least squares with imputation) effectiveness: 73 days longer than those who did not receive negative-pressure wound therapy (95% credible interval 33.8 to 112.8 days longer). Model A cost-effectiveness (associated incremental quality-adjusted life-years): observables –0.012 (standard error 0.005) and unobservables –0.008 (standard error 0.011). Model B (two-stage model, logistic and linear regression) effectiveness: 46 days longer than those who did not receive negative-pressure wound therapy (95% credible interval 19.6 to 72.5 days longer). Model B cost-effectiveness (associated incremental quality-adjusted life-years): observables –0.007 (standard error 0.004) and unobservables –0.027 (standard error 0.017). Patient interviews (n = 20) identified initial reactions to surgical wounds healing by secondary intention of shock and disbelief. Impaired quality of life characterised the long healing process, with particular impact on daily living for patients with families or in paid employment. Patients were willing to try any treatment promising wound healing. Health professionals (n = 12) had variable knowledge of surgical wound healing by secondary intention treatments and, frequently, favoured negative-pressure wound therapy, despite the lack of robust evidence. The pilot feasibility randomised controlled trial screened 248 patients for eligibility and subsequently recruited and randomised 40 participants to receive negative-pressure wound therapy or usual care (no negative-pressure wound therapy). Data indicated that it was feasible to complete a full randomised controlled trial to provide definitive evidence for the clinical effectiveness and cost-effectiveness of negative-pressure wound therapy as a treatment for surgical wounds healing by secondary intention. Key elements and recommendations for a larger randomised controlled trial were identified.

Limitations

This research programme was conducted in a single geographical area (i.e. Yorkshire and the Humber, UK) and local guidelines and practices may have affected treatment availability, and so may not represent UK-wide treatment choices. A wide range of wound types were included; however, some wound types may be under-represented, meaning that this research may not represent the overall surgical wound healing by secondary intention population. The lack of randomised controlled trial data on the relative effects of negative-pressure wound therapy in surgical wounds healing by secondary intention resulted in much of the economic modelling being based on observational data. Observational data, even with extensive adjustment, do not negate the potential for unresolved confounding to affect the results, which can reduce confidence in conclusions drawn from observational data. Definitive evidence from a randomised controlled trial may be the only way to overcome this lack of confidence.

Conclusions

This research has provided new information regarding the nature, extent, costs, impacts and outcomes of surgical wounds healing by secondary intention, treatment effectiveness, and the value and nature of future research, while addressing previous uncertainties regarding the problem of surgical wounds healing by secondary intention. Aspects of our research indicate that negative-pressure wound therapy is more costly and less effective than standard dressing for the healing of open surgical wounds. However, because this conclusion is based solely on observational data, it may be affected by unresolved confounding. Should a future randomised controlled trial be considered necessary, its design should reflect careful consideration of the findings of this programme of research.

Future work

This research signals the importance of further research on surgical wound healing by secondary intention. Key research questions raised by this programme of research include (1) which treatments are clinically effective and cost-effective for surgical wound healing by secondary intention for all patients or for particular patient subgroups? (2) Can particular prognostic factors predict time to healing of surgical wound healing by secondary intention? And (3) do psychosocial interventions have the potential to improve quality of life in people with hard-to-heal surgical wound healing by secondary intention? Given that negative-pressure wound therapy has been widely adopted, with relatively little evidence to support its use, the design and outcomes of a randomised controlled trial would need to be carefully considered. We focused in this research on wound healing, and maintain, based on the findings of patient interviews, that this is a key outcome for future research. Impacts of negative-pressure wound therapy on outcomes such as infection and reoperation should also be considered, as should patients’ views of the treatment. The type of patient group recruited and the outcomes of interest will all influence the duration of follow-up of any planned study. The comparator in any future study will also need careful consideration.

Trial registration

Current Controlled Trials ISRCTN12761776.

Funding

This project was funded by the National Institute for Health Research Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 8, No. 7. See the National Institute for Health Research Journals Library website for further project information.

Characterisation of baseline microbiological and host factors in an inception cohort of people with surgical wounds healing by secondary intention reveals circulating IL-6 levels as a potential predictive biomarker of healing

Background: More than 2 million people per year are treated for surgical wounds in the UK.  Over a quarter of these wounds are estimated to heal by secondary intention (from the “bottom up”) resulting in further complications and requiring increased healthcare resources. Identification of microbiological or host biomarkers that can predict healing outcomes may help to optimize the management of surgical wounds healing by secondary intention. However, the microbial and host factor heterogeneity amongst this diverse population is completely unexplored. Methods: We demonstrate feasibility of determining presence and levels of wound microbes and systemic host factors in an inception cohort of 54 people presenting with surgical wounds healing by secondary intention, who were subsequently followed-up for a period of 12-21 months. We present descriptive statistics for plasma levels of inflammatory, angiogenic cytokines and microRNAs, and we identify a range of wound colonizing microbes. We tentatively explore association with healing aiming to generate hypotheses for future research. Results: We report a potential correlation between poor healing outcomes and elevated interleukin (IL)-6 plasma levels at presentation (ρ=0.13) which requires confirmation.   Conclusions: This study demonstrates the degree of biological heterogeneity amongst people with surgical wounds healing by secondary intention and proves the feasibility of embedding a biomarker discovery study in a cohort study in surgical wounds. Our results are essential for designing large biomarker discovery studies to further investigate the potential validity of circulating IL-6 or other factors as novel predictive biomarkers of healing for surgical wounds healing by secondary intention.

Oral propranolol in the treatment of proliferating infantile haemangiomas: British Society for Paediatric Dermatology consensus guidelines

BACKGROUND

Infantile haemangiomas (IH) are the most common vascular tumours of infancy. Despite their frequency and potential complications, there are currently no unified U.K. guidelines for the treatment of IH with propranolol. There are still uncertainties and diverse opinions regarding indications, pretreatment investigations, its use in PHACES (posterior fossa malformations-haemangiomas-arterial anomalies-cardiac defects-eye abnormalities-sternal cleft and supraumbilical raphe) syndrome and cessation of treatment.

OBJECTIVES

To provide unified guidelines for the treatment of IH with propranolol.

METHODS

This study used a modified Delphi technique, which involved an international treatment survey, a systematic evidence review of the literature, a face-to-face multidisciplinary panel meeting and anonymous voting.

RESULTS

The expert panel achieved consensus on 47 statements in eight categories, including indications and contraindications for starting propranolol, pretreatment investigations, starting and target dose, monitoring of adverse effects, the use of propranolol in PHACES syndrome and how to stop treatment.

CONCLUSIONS

These consensus guidelines will help to standardize and simplify the treatment of IH with oral propranolol across the U.K. and assist in clinical decision-making.

AVURT: aspirin versus placebo for the treatment of venous leg ulcers - a Phase II pilot randomised controlled trial

BACKGROUND

Venous leg ulcers (VLUs) are the most common cause of leg ulceration, affecting 1 in 100 adults. VLUs may take many months to heal (25% fail to heal). Estimated prevalence is between 1% and 3% of the elderly population. Compression is the mainstay of treatment and few additional therapies exist to improve healing. Two previous trials have indicated that low-dose aspirin, as an adjunct to standard care, may improve healing time, but these trials were insufficiently robust. Aspirin is an inexpensive, widely used medication but its safety and efficacy in the treatment of VLUs remains to be established.

OBJECTIVES

Primary objective - to assess the effects of 300 mg of aspirin (daily) versus placebo on the time to healing of the reference VLU. Secondary objectives - to assess the feasibility of leading into a larger pragmatic Phase III trial and the safety of aspirin in this population.

DESIGN

A multicentred, pilot, Phase II randomised double-blind, parallel-group, placebo-controlled efficacy trial.

SETTING

Community leg ulcer clinics or services, hospital outpatient clinics, leg ulcer clinics, tissue viability clinics and wound clinics in England, Wales and Scotland.

PARTICIPANTS

Patients aged ≥ 18 years with a chronic VLU (i.e. the VLU is > 6 weeks in duration or the patient has a history of VLU) and who are not regularly taking aspirin.

INTERVENTIONS

300 mg of daily oral aspirin versus placebo. All patients were offered care in accordance with Scottish Intercollegiate Guidelines Network (SIGN) guidance with multicomponent compression therapy aiming to deliver 40 mmHg at the ankle when possible.

RANDOMISATION

Participants were allocated in a 1 : 1 (aspirin : placebo) ratio by the Research Pharmacy, St George's University Hospitals NHS Foundation Trust, using a randomisation schedule generated in advance by the investigational medicinal product manufacturer. Randomisation was stratified according to ulcer size (≤ 5cm² or > 5cm²).

MAIN OUTCOME MEASURE

The primary outcome was time to healing of the largest eligible ulcer (reference ulcer).

FEASIBILITY RESULTS – RECRUITMENT

27 patients were recruited from eight sites over a period of 8 months. The target of 100 patients was not achieved and two sites did not recruit. Barriers to recruitment included a short recruitment window and a large proportion of participants failing to meet the eligibility criteria.

RESULTS

The average age of the 27 randomised participants (placebo, n = 13; aspirin, n = 14) was 62 years (standard deviation 13 years), and two-thirds were male (n = 18). Participants had their reference ulcer for a median of 15 months, and the median size of ulcer was 17.1 cm². There was no evidence of a difference in time to healing of the reference ulcer between groups in an adjusted analysis for log-ulcer area and duration (hazard ratio 0.58, 95% confidence interval 0.18 to 1.85; p = 0.357). One expected, related serious adverse event was recorded for a participant in the aspirin group.

LIMITATIONS

The trial under-recruited because many patients did not meet the eligibility criteria.

CONCLUSIONS

There was no evidence that aspirin was efficacious in hastening the healing of chronic VLUs. It can be concluded that a larger Phase III (effectiveness) trial would not be feasible.

TRIAL REGISTRATION

Clinical Trials.gov NCT02333123; European Clinical Trials Database (EudraCT) 2014-003979-39.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 55. See the NIHR Journals Library website for further project information.

Trial of Remote Continuous versus Intermittent NEWS monitoring after major surgery (TRaCINg): protocol for a feasibility randomised controlled trial

Background

Despite medical advances, major surgery remains high risk. Up to 44% of patients experience postoperative complications, which can have huge impacts for patients and the healthcare system. Early recognition of postoperative complications is crucial in reducing morbidity and preventing long-term disability. The current standard of care is intermittent manual vital signs monitoring, but new wearable remote monitors offer the benefits of continuous vital signs monitoring without limiting the patient's mobility. The aim of this study is to evaluate the feasibility, acceptability and clinical impacts of continuous remote monitoring after major surgery.

Methods

The study is a randomised, controlled, unblinded, parallel group, feasibility trial. Adult patients undergoing elective major surgery will be invited to participate if they have the capacity to provided informed, written consent and do not have a cardiac pacemaker or an allergy to adhesives. Participants will be randomly assigned to receive continuous remote monitoring and normal National Early Warning Score (NEWS) monitoring (intervention group) or normal NEWS monitoring alone (control group). Continuous remote monitoring will be achieved using the SensiumVitals® wireless patch which is worn on the patient's chest and monitors heart rate, respiratory rate and temperature continuously and alerts the nurse when there is deviation from pre-set physiological norms. Participants will be followed up throughout their hospital admission and for 30 days after discharge. Feasibility will be assessed by evaluating recruitment rate, adherence to protocol and randomisation, and the amount of missing data. The acceptability of the patch to nursing staff and patients will be assessed using questionnaires and interviews. Clinical outcomes will include time to antibiotics in cases of sepsis, length of hospital stay, number of critical care admissions and rate of readmission within 30 days of discharge.

Discussion

Early detection and treatment of complications minimises the need for critical care, improves patient outcomes, and produces significant cost savings for the healthcare system. Remote continuous monitoring systems have the potential to allow earlier detection of complications, but evidence from the literature is mixed. Demonstrating significant benefit over intermittent monitoring to offset the practical and economic implications of continuous monitoring requires well-controlled studies in high-risk populations to demonstrate significant differences in clinical outcomes; this feasibility trial seeks to provide evidence of how best to conduct such a confirmatory trial.

Trial registration

This study is listed on the ISRCTN registry with study ID ISRCTN16601772.

Pilot feasibility randomized clinical trial of negative-pressure wound therapy versus usual care in patients with surgical wounds healing by secondary intention

Background

Surgical wounds healing by secondary intention (SWHSI) are increasingly being treated with negative-pressure wound therapy (NPWT) despite a lack of high-quality research evidence regarding its clinical and cost-effectiveness. This pilot feasibility RCT aimed to assess the methods for and feasibility of conducting a future definitive RCT of NPWT for the treatment of SWHSI.

Methods

Eligible consenting adult patients receiving care at the study sites (2 acute and 1 community) and with a SWHSI appropriate for NPWT or wound dressing treatment were randomized 1 : 1 centrally to receive NPWT or usual care (no NPWT). Participants were followed up every 1-2 weeks for 3 months. Feasibility (recruitment rate, time to intervention delivery) and clinical (time to wound healing) outcomes were assessed.

Results

A total of 248 participants were screened for eligibility; 40 (16·1 per cent) were randomized, 19 to NPWT and 21 to usual care. Twenty-four of the 40 wounds were located on the foot. Participants received NPWT for a median of 18 (range 0-72) days. Two participants in the NPWT group never received the intervention and 14 received NPWT within 48 h of randomization. Five participants in the usual care group received NPWT during the study. Ten of the 40 wounds were deemed to have healed during the study.

Conclusion

A full-scale RCT to investigate the clinical and cost-effectiveness of NPWT for SWHSI is feasible. This study identified crucial information on recruitment rates and data collection methods to consider during the design of a definitive RCT. Registration number: ISRCTN12761776 (http://www.iscrtn.com).

Can patient involvement improve patient safety? A cluster randomised control trial of the Patient Reporting and Action for a Safe Environment (PRASE) intervention

OBJECTIVE

To evaluate the efficacy of the Patient Reporting and Action for a Safe Environment intervention.

DESIGN

A multicentre cluster randomised controlled trial.

SETTING

Clusters were 33 hospital wards within five hospitals in the UK.

PARTICIPANTS

All patients able to give informed consent were eligible to take part. Wards were allocated to the intervention or control condition.

INTERVENTION

The ward-level intervention comprised two tools: (1) a questionnaire that asked patients about factors contributing to safety (patient measure of safety (PMOS)) and (2) a proforma for patients to report both safety concerns and positive experiences (patient incident reporting tool). Feedback was considered in multidisciplinary action planning meetings.

MEASUREMENTS

Primary outcomes were routinely collected ward-level harm-free care (HFC) scores and patient-level feedback on safety (PMOS).

RESULTS

Intervention uptake and retention of wards was 100% and patient participation was high (86%). We found no significant effect of the intervention on any outcomes at 6 or 12 months. However, for new harms (ie, those for which the wards were directly accountable) intervention wards did show greater, though non-significant, improvement compared with control wards. Analyses also indicated that improvements were largest for wards that showed the greatest compliance with the intervention.

LIMITATIONS

Adherence to the intervention, particularly the implementation of action plans, was poor. Patient safety outcomes may represent too blunt a measure.

CONCLUSIONS

Patients are willing to provide feedback about the safety of their care. However, we were unable to demonstrate any overall effect of this intervention on either measure of patient safety and therefore cannot recommend this intervention for wider uptake. Findings indicate promise for increasing HFC where wards implement ≥75% of the intervention components.

TRIAL REGISTRATION NUMBER

ISRCTN07689702; pre-results.

Negative pressure wound therapy versus usual care for Surgical Wounds Healing by Secondary Intention (SWHSI trial): study protocol for a randomised controlled pilot trial

BACKGROUND

Most incisions following surgery heal by primary intention, with the edges of the wound apposed with sutures or clips. However, some wounds may break open or be left to heal from the bottom up (i.e. healing by secondary intention). Surgical Wounds Healing by Secondary Intention (SWHSI) are often more complex to manage, and require additional treatments during the course of healing. There is significant uncertainty regarding the best treatment for these complex wounds, with limited robust evidence regarding the clinical and cost-effectiveness of different dressings and treatments; one such treatment is Negative Pressure Wound Therapy (NPWT) which is frequently used in the management of SWHSI. Previous randomised controlled trials (RCTs) of NPWT have failed to recruit to time and target, thus we aimed to conduct a pilot RCT to assess the feasibility of conducting a future, full-scale RCT.

METHODS

This pilot RCT will test the methods and feasibility of recruiting, randomising, and retaining participants into a larger trial of NPWT verses usual care for patients with SWHSI. Participants will be randomised to receive either NPWT or usual care (no NPWT) and will be followed up for 3 months.

DISCUSSION

This study will provide a full assessment of methods for, and feasibility of, recruiting, randomising, and retaining patients with SWHSI in a trial of NPWT versus usual care. On the basis of this pilot trial, a full trial may be proposed in the future which will provide additional, robust evidence on the clinical and cost-effectiveness of NPWT in the management of SWHSI.

TRIAL REGISTRATION

Clinical Trial Registry: ISRCTN12761776 , registered on 10 December 2015 - retrospective registration.

Wounds research for patient benefit: a 5-year programme of research

Background

Complex wounds are those that heal by secondary intention and include lower-limb ulcers, pressure ulcers and some surgical wounds. The care of people with complex wounds is costly, with care mainly being delivered by community nurses. There is a lack of current, high-quality data regarding the numbers and types of people affected, care received and outcomes achieved.

Objectives

To (1) assess how high-quality data about complex wounds can be captured effectively for use in both service planning and research while ensuring integration with current clinical data collection systems and minimal impact on staff time; (2) investigate whether or not a clinical register of people with complex wounds could give valid estimates of treatment effects, thus reducing dependence on large-scale randomised controlled trials (RCTs); (3) identify the most important research questions and outcomes for people with complex wounds from the perspectives of patients, carers and health-care professionals; (4) evaluate the potential contributions to decision-making of individual patient data meta-analysis and mixed treatment comparison meta-analysis; and (5) complete and update systematic reviews in topic areas of high priority.

Methods

To meet objectives 1 and 2 we conducted a prevalence survey and developed and piloted a longitudinal disease register. A consultative, deliberative method and in-depth interviews were undertaken to address objective 3. To address objectives 4 and 5 we conducted systematic reviews including mixed treatment comparison meta-analysis.

Results

From the prevalence survey we estimated the point prevalence of all complex wounds to be 1.47 per 1000 people (95% confidence interval 1.38 to 1.56 per 1000 people). Pressure ulcers and venous leg ulcers were the most common type of complex wound. A total of 195 people with a complex wound were recruited to a complex wounds register pilot. We established the feasibility of correctly identifying, extracting and transferring routine NHS data into the register; however, participant recruitment, data collection and tracking individual wounds in people with multiple wounds were challenging. Most patients and health professionals regarded healing of the wound as the primary treatment goal. Patients were greatly troubled by the social consequences of having a complex wound. Complex wounds are frequently a consequence of, and are themselves, a long-term condition but treatment is usually focused on healing the wound. Consultative, deliberative research agenda setting on pressure ulcer prevention and treatment with patients, carers and clinicians yielded 960 treatment uncertainties and a top 12 list of research priorities. Of 167 RCTs of complex wound treatments in a systematic review of study quality, 41% did not specify a primary outcome and the overall quality of the conduct and reporting of the research was poor. Mixed-treatment comparison meta-analysis in areas of high priority identified that matrix hydrocolloid dressings had the highest probability (70%) of being the most effective dressing for diabetic foot ulcers, whereas a hyaluronan fleece dressing had the highest probability (35%) of being the most effective dressing for venous ulcers; however, the quality of this evidence was low and uncertainty is high.

Conclusions

Complex wounds are common and costly with a poor evidence base for many frequent clinical decisions. There is little routine clinical data collection in community nursing. A prospective complex wounds register has the potential to both assist clinical decision-making and provide important research evidence but would be challenging to implement without investment in information technology in NHS community services. Future work should focus on developing insights into typical wound healing trajectories, identifying factors that are prognostic for healing and assessing the cost-effectiveness of selected wound treatments.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Acupuncture for irritable bowel syndrome: 2-year follow-up of a randomised controlled trial

Background

A recent randomised controlled trial (RCT) of acupuncture as a treatment for irritable bowel syndrome (IBS) demonstrated sustained benefits over a period of 12 months post-randomisation.

Aim

To extend the trial follow-up to evaluate the effects of acupuncture at 24 months post-randomisation.

Methods

Patients in primary care with ongoing IBS were recruited to a two-arm pragmatic RCT of acupuncture for IBS. Participants were randomised to the offer of up to 10 weekly sessions of acupuncture plus usual care (n=116 patients) or to continue with usual care alone (n=117). The primary outcome was the self-reported IBS symptom severity score (IBS SSS) measured at 24 months post-randomisation. Analysis was by intention-to-treat using an unstructured multivariate linear model incorporating all repeated measures.

Results

The overall response rate was 61%. The adjusted difference in mean IBS SSS at 24 months was −18.28 (95% CI −40.95 to 4.40) in favour of the acupuncture arm. Differences at earlier time points estimated from the multivariate model were: −27.27 (−47.69 to −6.86) at 3 months; −23.69 (−45.17 to −2.21) at 6 months; −24.09 (−45.59 to −2.59) at 9 months; and −23.06 (−44.52 to −1.59) at 12 months.

Conclusions

There were no statistically significant differences between the acupuncture and usual care groups in IBS SSS at 24 months post-randomisation, and the point estimate for the mean difference was approximately 80% of the size of the statistically significant results seen at 6, 9 and 12 months.

Trial registration number

ISRCTN08827905.

Exhaled nitric oxide monitoring does not reduce exacerbation frequency or inhaled corticosteroid dose in paediatric asthma: a randomised controlled trial

INTRODUCTION

Inhaled corticosteroid therapy (ICS) for asthma is currently modified according to symptoms and lung function. Fractional exhaled nitric oxide (FENO) has been demonstrated to be a non-invasive marker of eosinophilic inflammation. Studies of FENO-driven asthma management show variable success. Objectives: This study aimed to evaluate whether monitoring FENO can improve outpatient management of children with moderate to severe asthma using a pragmatic design.

METHODS

Children aged 6–17 years with moderate to severe asthma were recruited. Their asthma was stabilised before randomisation to FENO-driven therapy or to a standard management group where therapy was driven by conventional markers of asthma control. ICS or long-acting bronchodilator therapies were altered according to FENO levels in combination with reported symptoms in the FENO group. Participants were assessed 2 monthly for 12 months. ICS dose and exacerbation frequency change were compared between groups in an intention to treat analysis.

RESULTS

Ninety children were randomised. No difference was found between the two groups in either change in corticosteroid dose or exacerbation frequency. Results were similar in a planned secondary analysis of atopic asthmatics.

CONCLUSION

FENO-guided ICS titration does not appear to reduce corticosteroid usage or exacerbation frequency in paediatric outpatients with moderate to severe asthma. This may reflect limitations in FENO-driven management algorithms, as there are now concerns that FENO levels relate to atopy as much as they relate to asthma control.

Assessing the feasibility of evaluating and delivering a physical activity intervention for pre-school children: a pilot randomised controlled trial

Background

Few evidence-based physical activity interventions for pre-school children are available. This two-armed pilot cluster randomised controlled trial aimed to evaluate the feasibility of conducting a full-scale trial and of delivering an outdoor physical activity intervention for pre-school children.

Methods

School was the unit of randomisation, and follow-up occurred at 10 and 52 weeks. Trial feasibility was assessed by recruitment, retention and completion rates of primary (daily moderate-to-vigorous physical activity (MVPA)) and secondary (anthropometric, quality of life, self-efficacy) outcomes. Potential effectiveness was assessed for the primary outcome using a linear regression model comparing MVPA between trial arms adjusting for clustering by school. Feasibility of delivering the intervention was assessed by intervention fidelity and attendance. Semi-structured interviews with parents, intervention facilitators, and head teachers explored acceptability and capability to deliver the intervention as well as acceptability of the study design.

Results

Recruitment rates were 37 % of schools (n = 10 schools) and 48 % of pre-school children (n = 164 children). Retention of children to the trial at 52 weeks was 83.5 %. Thirty-nine percent of children had valid primary outcome accelerometer data at baseline and 52 weeks. Response rates for secondary outcome measures ranged from 52 to 88 % at 10 weeks and 59 to 80 % at 52 weeks. The mean difference in daily MVPA between trial arms at 52 weeks was 0.4, 95 % CI 16.3 to 17.0; p = 0.96. Fidelity of intervention implementation was 81 %. Intervention attendance was higher (82 %) during the summer initiation phase compared to autumn/spring initiation (50 %). Parents, facilitators and head teachers found the intervention acceptable and beneficial.

Conclusions

Recruitment and retention rates suggest a trial in this outdoor setting with this population was feasible but is weather sensitive. However, strategies to increase accelerometer wear-time would need to be implemented for reliable primary outcome data to be obtained. There was high implementation fidelity by facilitators, and the intervention was seen as acceptable and deliverable. However, attendance was low and preliminary data showed no evidence of intervention effectiveness. A revised intervention, building on the successful elements of this pilot alongside adapting implementation strategies to improve attendance, should therefore be considered.

Trial registration

Trial registry name and number: Current Controlled Trials, ISRCTN54165860. Date of registration: 4 September 2012.

Aspirin for Venous Ulcers: Randomised Trial (AVURT): study protocol for a randomised controlled trial

BACKGROUND

Venous leg ulcers (VLUs) are the commonest cause of leg ulceration, affecting 1 in 100 adults. There is a significant health burden associated with VLUs - it is estimated that the cost of treatment for 1 ulcer is up to £1300 per year in the NHS. The mainstay of treatment is with graduated compression bandaging; however, treatment is often prolonged and up to one quarter of venous leg ulcers do not heal despite standard care. Two previous trials have suggested that low-dose aspirin, as an adjunct to standard care, may hasten healing, but these trials were small and of poor quality. Aspirin is an inexpensive, widely used medication but its safety and efficacy in the treatment of VLUs remains to be established.

METHODS/DESIGN

AVURT is a phase II randomised double blind, parallel-group, placebo-controlled efficacy trial. The primary objective is to examine whether aspirin, in addition to standard care, is effective in patients with chronic VLUs (i.e. over 6 weeks in duration or a history of VLU). Secondary objectives include feasibility and safety of aspirin in this population. A target of 100 participants, identified from community leg ulcer clinics and hospital clinics, will be randomised to receive either 300 mg of aspirin once daily or placebo. All participants will receive standard care with compression therapy. The primary outcome will be time to healing of the reference ulcer. Follow-up will occur for a maximum of 27 weeks. The primary analysis will use a Cox proportional hazards model to compare time to healing using the principles of intention-to-treat. Secondary outcomes will include ulcer size, pain evaluation, compliance and adverse events.

DISCUSSION

The AVURT trial will investigate the efficacy and safety of aspirin as a treatment for VLU and will inform on the feasibility of proceeding to a larger phase III study. This study will address the paucity of information currently available regarding aspirin therapy to treat VLU.

TRIAL REGISTRATION

The study is registered on a public database with clinicaltrials.gov ( NCT02333123 ; registered on 5 November 2014).

A multi-centre, parallel group superiority trial of silk therapeutic clothing compared to standard care for the management of eczema in children (CLOTHES Trial): study protocol for a randomised controlled trial

Background

Eczema is a chronic, itchy skin condition that can have a large impact on the quality of life of patients and their families. People with eczema are often keen to try out non-pharmacological therapies like silk therapeutic garments that could reduce itching or the damage caused by scratching. However, the effectiveness and cost-effectiveness of these garments in the management of eczema has yet to be proven. The CLOTHES Trial will test the hypothesis that ‘silk therapeutic garments plus standard eczema care’ is superior to ‘standard care alone’ for children with moderate to severe eczema.

Methods/Design

Parallel group, observer-blind, pragmatic, multi-centre randomised controlled trial of 6 months’ duration.

Three hundred children aged 1 to 15 years with moderate to severe eczema will be randomised (1:1) to receive silk therapeutic garments plus standard eczema care, or standard eczema care alone. Primary outcome is eczema severity, as assessed by trained and blinded investigators at 2, 4 and 6 months (using the Eczema Area and Severity Index (EASI)). Secondary outcomes include: patient-reported eczema symptoms (collected weekly for 6 months to capture long-term control); global assessment of severity; quality of life of the child, family and main carer; use of standard eczema treatments (emollients, corticosteroids applied topically, calcineurin inhibitors applied topically and wet wraps); frequency of infections; and cost-effectiveness. The acceptability and durability of the clothing will also be assessed, as will adherence to wearing the garments. A nested qualitative study will assess the views of a subset of children wearing the garments and their parents, and those of healthcare providers and commissioners.

Randomisation uses a computer-generated sequence of permuted blocks of randomly varying size, stratified by recruiting hospital and child’s age (< 2 years; 2 to 5 years; > 5 years), and concealed using a secure web-based system. The sequence of treatment allocations will remain concealed until randomisation and data collection are complete.

Recruitment is taking place from November 2013 to May 2015, and the trial will be completed in 2016. Full details of results will be published in the National Institute for Health Research Journal series.

Trial registration

Current Controlled Trials ISRCTN77261365 (registered 11 November 2013).

Randomized trial within a trial of yellow 'post-it notes' did not improve questionnaire response rates among participants in a trial of treatments for neck pain

RATIONALE

Attrition is a threat to the validity of randomized trials. Few randomized studies have been conducted within randomized trials to test methods of reducing attrition.

AIM

To test whether using yellow post-it notes on follow-up questionnaires in the ATLAS treatment trial for neck pain reduces attrition.

METHOD

Nested trial within a trial. ATLAS participants were randomized to have their 6-month follow-up questionnaire have a 3' yellow post-it note with a handwritten message encouraging return of questionnaire.

RESULTS

499 participants were independently randomized using simple allocation to receive the post-it notes or not. Two hundred fifteen of the 256 (84.0%) participants in the intervention group returned their questionnaire compared with 205 of the 243 (84.4%) in the control group. There was no difference in time to response.

CONCLUSION

Yellow post-it notes do not enhance questionnaire return rates for participants in a randomized trial of neck pain.

Deletion of the BDNF truncated receptor TrkB.T1 delays disease onset in a mouse model of amyotrophic lateral sclerosis

Brain Derived Neurotrophic Factor (BDNF) exerts strong pro-survival effects on developing and injured motoneurons. However, in clinical trials, BDNF has failed to benefit patients with amyotrophic lateral sclerosis (ALS). To date, the cause of this failure remains unclear. Motoneurons express the TrkB kinase receptor but also high levels of the truncated TrkB.T1 receptor isoform. Thus, we investigated whether the presence of this receptor may affect the response of diseased motoneurons to endogenous BDNF. We deleted TrkB.T1 in the hSOD1^G93A ALS mouse model and evaluated the impact of this mutation on motoneuron death, muscle weakness and disease progression. We found that TrkB.T1 deletion significantly slowed the onset of motor neuron degeneration. Moreover, it delayed the development of muscle weakness by 33 days. Although the life span of the animals was not affected we observed an overall improvement in the neurological score at the late stage of the disease. To investigate the effectiveness of strategies aimed at bypassing the TrkB.T1 limit to BDNF signaling we treated SOD1 mutant mice with the adenosine A2A receptor agonist CGS21680, which can activate motoneuron TrkB receptor signaling independent of neurotrophins. We found that CGS21680 treatment slowed the onset of motor neuron degeneration and muscle weakness similarly to TrkB.T1 removal. Together, our data provide evidence that endogenous TrkB.T1 limits motoneuron responsiveness to BDNF in vivo and suggest that new strategies such as Trk receptor transactivation may be used for therapeutic intervention in ALS or other neurodegenerative disorders.