Alive and Ventilator Free: A Hierarchical, Composite Outcome for Clinical Trials in the Acute Respiratory Distress Syndrome

Nebulized Furosemide for Pulmonary Inflammation in Intubated Patients With COVID-19: A Phase 2 Randomized Controlled Double-Blind Study

OBJECTIVES

Respiratory failure secondary to COVID-19 is associated with morbidity and mortality. Current anti-inflammatory therapies are effective but are given systemically and have significant side effects. Furosemide has anti-inflammatory properties, can be administered by inhalation, and is inexpensive. We investigated the efficacy of nebulized furosemide as an adjunctive therapy for COVID-19 respiratory failure.

DESIGN

A double-blind, randomized, placebo-controlled trial.

SETTING

Multicenter ICU study.

PATIENTS

Adults requiring invasive mechanical ventilation secondary to COVID-19.

INTERVENTION

Patients were randomized within 48 hours of intubation to receive inhaled furosemide or placebo until day 28, death, or liberation from mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

The study was stopped early due to waning incidence of COVID-19; 39 patients were available for analysis with mean ± sd age of 70.5 (10.8) years, Acute Physiology and Chronic Health Evaluation II 26.1 (7.8) and Fio2 60.0% (21.9). Baseline characteristics were similar between the groups. For the primary outcome of change in Pao2/Fio2 ratio between day 1 and day 6, it was +31.4 (83.5) in the furosemide arm versus +20.1 (92.8) in the control (p = 0.58). For secondary outcomes, furosemide versus control: 60-day mortality was 48% versus 71% (p = 0.20), hospital stay was 25.6 (21.9) versus 27.4 (25.0) days, p = 0.94 and VFD was 6.0 (9.1) versus 3.1 (7.1), p value of equals to 0.28. A post hoc analysis of the hierarchical composite outcome, alive and ventilator-free favored furosemide. There were no adverse events.

CONCLUSIONS

In this trial of inhaled furosemide for COVID-19 respiratory failure, differences in Pao2/Fio2 ratio to day 6 and other clinical outcomes were not significantly different, although the trial was underpowered due to early termination. Given the favorable profile of inhaled furosemide, further study is warranted in disease states where acute pulmonary inflammation contributes to the underlying pathophysiology.

Sample size estimation in clinical trials using ventilator-free days as the primary outcome: a systematic review

BACKGROUND

Ventilator-free days (VFDs) are a composite endpoint increasingly used as the primary outcome in critical care trials. However, because of the skewed distribution and competitive risk between components, sample size estimation remains challenging. This systematic review was conducted to systematically assess whether the sample size was congruent, as calculated to evaluate VFDs in trials, with VFDs' distribution and the impact of alternative methods on sample size estimation.

METHODS

A systematic literature search was conducted within the PubMed and Embase databases for randomized clinical trials in adults with VFDs as the primary outcome until December 2021. We focused on peer-reviewed journals with 2021 impact factors greater than five. After reviewing definitions of VFDs, we extracted the sample size and methods used for its estimation. The data were collected by two independent investigators and recorded in a standardized, pilot-tested forms tool. Sample sizes were calculated using alternative statistical approaches, and risks of bias were assessed with the Cochrane risk-of-bias tool.

RESULTS

Of the 26 clinical trials included, 19 (73%) raised "some concerns" when assessing risks of bias. Twenty-four (92%) trials were two-arm superiority trials, and 23 (89%) were conducted at multiple sites. Almost all the trials (96%) were unable to consider the unique distribution of VFDs and death as a competitive risk. Moreover, significant heterogeneity was found in the definitions of VFDs, especially regarding varying start time and type of respiratory support. Methods for sample size estimation were also heterogeneous, and simple models, such as the Mann-Whitney-Wilcoxon rank-sum test, were used in 14 (54%) trials. Finally, the sample sizes calculated varied by a factor of 1.6 to 17.4.

CONCLUSIONS

A standardized definition and methodology for VFDs, including the use of a core outcome set, seems to be required. Indeed, this could facilitate the interpretation of findings in clinical trials, as well as their construction, especially the sample size estimation which is a trade-off between cost, ethics, and statistical power. Systematic review registration PROSPERO ID: CRD42021282304. Registered 15 December 2021 ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021282304 ).

Impact of a multifaceted early mobility intervention for critically ill children - the PICU Up! trial: study protocol for a multicenter stepped-wedge cluster randomized controlled trial

BACKGROUND

Over 50% of all critically ill children develop preventable intensive care unit-acquired morbidity. Early and progressive mobility is associated with improved outcomes in critically ill adults including shortened duration of mechanical ventilation and improved muscle strength. However, the clinical effectiveness of early and progressive mobility in the pediatric intensive care unit has never been rigorously studied. The objective of the study is to evaluate if the PICU Up! intervention, delivered in real-world conditions, decreases mechanical ventilation duration (primary outcome) and improves delirium and functional status compared to usual care in critically ill children. Additionally, the study aims to identify factors associated with reliable PICU Up! delivery.

METHODS

The PICU Up! trial is a stepped-wedge, cluster-randomized trial of a pragmatic, interprofessional, and multifaceted early mobility intervention (PICU Up!) conducted in 10 pediatric intensive care units (PICUs). The trial's primary outcome is days alive free of mechanical ventilation (through day 21). Secondary outcomes include days alive and delirium- and coma-free (ADCF), days alive and coma-free (ACF), days alive, as well as functional status at the earlier of PICU discharge or day 21. Over a 2-year period, data will be collected on 1,440 PICU patients. The study includes an embedded process evaluation to identify factors associated with reliable PICU Up! delivery.

DISCUSSION

This study will examine whether a multifaceted strategy to optimize early mobility affects the duration of mechanical ventilation, delirium incidence, and functional outcomes in critically ill children. This study will provide new and important evidence on ways to optimize short and long-term outcomes for pediatric patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04989790. Registered on August 4, 2021.

Mechanical power of ventilation and driving pressure: two undervalued parameters for pre extracorporeal membrane oxygenation ventilation and during daily management?

The current ARDS guidelines highly recommend lung protective ventilation which include plateau pressure (P_plat < 30 cm H₂O), positive end expiratory pressure (PEEP > 5 cm H₂O) and tidal volume (V_t of 6 ml/kg) of predicted body weight. In contrast, the ELSO guidelines suggest the evaluation of an indication of veno-venous extracorporeal membrane oxygenation (ECMO) due to hypoxemic or hypercapnic respiratory failure or as bridge to lung transplantation. Finally, these recommendations remain a wide range of scope of interpretation. However, particularly patients with moderate-severe to severe ARDS might benefit from strict adherence to lung protective ventilation strategies. Subsequently, we discuss whether extended physiological ventilation parameter analysis might be relevant for indication of ECMO support and can be implemented during the daily routine evaluation of ARDS patients. Particularly, this viewpoint focus on driving pressure and mechanical power.

Generalised pairwise comparisons for trend: An extension to the win ratio and win odds for dose-response and prognostic variable analysis with arbitrary statements of outcome preference

The win ratio is a novel approach for handling complex patient outcomes that have seen considerable interest in the medical statistics literature, and operates by considering all-to-all pairwise statements of preference on outcomes. Recent extensions to the method have focused on the two-group case, with few developments made for considering the impact of a well-ordered explanatory variable, which would allow for dose-response analysis or the analysis of links between complex patient outcomes and prognostic variables. Where such methods have been developed, they are semiparametric methods that can only be applied to survival outcomes. In this article, we introduce the generalised pairwise comparison for trend, a modified form of Agresti's generalised odds ratio. This approach is capable of considering arbitrary statements of preference, thus enabling its use across all types of outcome data. We provide a simulation study validating the approach and illustrate it with three clinical applications in stroke research.

Delivery of Lung-protective Ventilation for Acute Respiratory Distress Syndrome: A Hybrid Implementation-Effectiveness Trial

Rationale: Lung-protective ventilation (LPV) improves outcomes for patients with acute respiratory distress syndrome (ARDS), but adherence remains inadequate. Objectives: To measure the process and clinical impacts of implementation of a science-based intervention to improve LPV adherence for patients with ARDS, in part by increased use of clinical decision support (CDS). Methods: We conducted a type III hybrid implementation/effectiveness pilot trial enrolling adult patients with ARDS admitted to three hospitals before and after the launch of a multimodal implementation intervention to increase the use of mechanical ventilation CDS and improve LPV adherence. The primary outcome was patients' percentage of time adherent to low tidal volume (⩽6.5 ml/kg predicted body weight) ventilation (LTVV). Secondary outcomes included adherence to prescribed oxygenation settings, the use of the CDS tool's independent oxygenation and ventilation components, ventilator-free days, and mortality. Analyses employed multivariable regression to compare adjusted pre- versus postintervention outcomes after the exclusion of a postintervention wash-in period. A sensitivity analysis measured process outcomes' level and trend change postintervention using segmented regression. Results: The 446 included patients had a mean age of 60 years, and 43% were female. Demographic and clinical characteristics were similar pre- versus postintervention. The adjusted proportion of adherent time increased postintervention for LTVV (9.2%; 95% confidence interval [CI], 3.8-14.5%) and prescribed oxygenation settings (11.9%; 95% CI, 7.2-16.5%), as did the probability patients spent ⩾90% of ventilated time on LTVV (adjusted odds ratio [aOR] 2.58; 95% CI, 1.64-4.10) and use of ventilation CDS (aOR, 41.3%; 95% CI, 35.9-46.7%) and oxygenation CDS (aOR, 54.3%; 95% CI, 50.9-57.7%). Ventilator-free days (aOR, 1.15; 95% CI, 0.81-1.62) and 28-day mortality (aOR, 0.78; 95% CI, 0.50-1.20) did not change significantly after intervention. Segmented regression analysis supported a causal relationship between the intervention and improved CDS usage but suggested trends before intervention rather than the studied intervention could explain increased LPV adherence after the intervention. Conclusions: In this pilot trial, a multimodal implementation intervention was associated with increased use of ventilator management CDS for patients with ARDS but was not associated with differences in clinical outcomes and may not have independently caused the observed postintervention improvements in LPV adherence. Clinical trial registered with www.clinicaltrials.gov (NCT03984175).

Oxygen-Free Days as an Outcome Measure in Clinical Trials of Therapies for COVID-19 and Other Causes of New-Onset Hypoxemia

Mortality historically has been the primary outcome of choice for acute and critical care clinical trials. However, undue reliance on mortality can limit the scope of trials that can be performed. Large sample sizes are usually needed for trials powered for a mortality outcome, and focusing solely on mortality fails to recognize the importance that reducing morbidity can have on patients' lives. The COVID-19 pandemic has highlighted the need for rapid, efficient trials to rigorously evaluate new therapies for hospitalized patients with acute lung injury. Oxygen-free days (OFDs) is a novel outcome for clinical trials that is a composite of mortality and duration of new supplemental oxygen use. It is designed to characterize recovery from acute lung injury in populations with a high prevalence of new hypoxemia and supplemental oxygen use. In these populations, OFDs captures two patient-centered consequences of acute lung injury: mortality and hypoxemic lung dysfunction. Power to detect differences in OFDs typically is greater than that for other clinical trial outcomes, such as mortality and ventilator-free days. OFDs is the primary outcome for the Fourth Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV-4) Host Tissue platform, which evaluates novel therapies targeting the host response to COVID-19 among adults hospitalized with COVID-19 and new hypoxemia. This article outlines the rationale for use of OFDs as an outcome for clinical trials, proposes a standardized method for defining and analyzing OFDs, and provides a framework for sample size calculations using the OFD outcome.

A Randomized Double-Blinded Placebo Controlled Trial of Clazakizumab for the Treatment of COVID-19 Pneumonia With Hyperinflammation

OBJECTIVES

We designed this study to test whether clazakizumab, a direct interleukin-6 inhibitor, benefits patients hospitalized with severe or critical COVID-19 disease accompanied by hyperinflammation.

DESIGN

Multicenter, randomized, double-blinded, placebo-controlled, seamless phase II/III trial.

SETTING

Five U.S. medical centers.

PATIENTS

Adults inpatients with severe COVID-19 disease and hyperinflammation.

INTERVENTIONS

Eighty-one patients enrolled in phase II, randomized 1:1:1 to low-dose (12.5 mg) or high-dose (25 mg) clazakizumab or placebo. Ninety-seven patients enrolled in phase III, randomized 1:1 to high-dose clazakizumab or placebo.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was 28-day ventilator-free survival. Secondary outcomes included overall survival, frequency and duration of intubation, and frequency and duration of ICU admission. Per Data Safety and Monitoring Board recommendations, additional secondary outcomes describing clinical status and status changes, as measured by an ordinal scale, were added. Bayesian cumulative proportional odds, logistic, and Poisson regression models were used. The low-dose arm was dropped when the phase II study suggested superiority of the high-dose arm. We report on 152 patients, 74 randomized to placebo and 78 to high-dose clazakizumab. Patients receiving clazakizumab had greater odds of 28-day ventilator-free survival (odds ratio [OR] = 3.84; p [OR > 1] 99.9%), as well as overall survival at 28 and 60 days (OR = 1.75; p [OR > 1] 86.5% and OR = 2.53; p [OR > 1] 97.7%). Clazakizumab was associated with lower odds of intubation (OR = 0.2; p [OR] < 1; 99.9%) and ICU admission (OR = 0.26; p [OR < 1] 99.6%); shorter durations of ventilation and ICU stay (risk ratio [RR] < 0.75; p [RR < 1] > 99% for both); and greater odds of improved clinical status at 14, 28, and 60 days (OR = 2.32, p [OR > 1] 98.1%; OR = 3.36, p [OR > 1] 99.6%; and OR = 3.52, p [OR > 1] 99.8%, respectively).

CONCLUSIONS

Clazakizumab significantly improved 28-day ventilator-free survival, 28- and 60-day overall survival, as well as clinical outcomes in hospitalized patients with COVID-19 and hyperinflammation.

Lenzilumab in hospitalised patients with COVID-19 pneumonia (LIVE-AIR): a phase 3, randomised, placebo-controlled trial

Background

The pathophysiology of COVID-19 includes immune-mediated hyperinflammation, which could potentially lead to respiratory failure and death. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is among cytokines that contribute to the inflammatory processes. Lenzilumab, a GM-CSF neutralising monoclonal antibody, was investigated in the LIVE-AIR trial to assess its efficacy and safety in treating COVID-19 beyond available treatments.

Methods

In LIVE-AIR, a phase 3, randomised, double-blind, placebo-controlled trial, hospitalised adult patients with COVID-19 pneumonia not requiring invasive mechanical ventilation were recruited from 29 sites in the USA and Brazil and were randomly assigned (1:1) to receive three intravenous doses of lenzilumab (600 mg per dose) or placebo delivered 8 h apart. All patients received standard supportive care, including the use of remdesivir and corticosteroids. Patients were stratified at randomisation by age and disease severity. The primary endpoint was survival without invasive mechanical ventilation to day 28 in the modified intention-to-treat population (mITT), comprising all randomised participants who received at least one dose of study drug under the documented supervision of the principal investigator or sub-investigator. Adverse events were assessed in all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT04351152, and is completed.

Findings

Patients were enrolled from May 5, 2020, until Jan 27, 2021. 528 patients were screened, of whom 520 were randomly assigned and included in the intention-to-treat population. 479 of these patients (n=236, lenzilumab; n=243, placebo) were included in the mITT analysis for the primary outcome. Baseline demographics were similar between groups. 311 (65%) participants were males, mean age was 61 (SD 14) years at baseline, and median C-reactive protein concentration was 79 (IQR 41–137) mg/L. Steroids were administered to 449 (94%) patients and remdesivir to 347 (72%) patients; 331 (69%) patients received both treatments. Survival without invasive mechanical ventilation to day 28 was achieved in 198 (84%; 95% CI 79–89) participants in the lenzilumab group and in 190 (78%; 72–83) patients in the placebo group, and the likelihood of survival was greater with lenzilumab than placebo (hazard ratio 1·54; 95% CI 1·02–2·32; p=0·040). 68 (27%) of 255 patients in the lenzilumab group and 84 (33%) of 257 patients in the placebo group experienced at least one adverse event that was at least grade 3 in severity based on CTCAE criteria. The most common treatment-emergent adverse events of grade 3 or higher were related to respiratory disorders (26%) and cardiac disorders (6%) and none led to death.

Interpretation

Lenzilumab significantly improved survival without invasive mechanical ventilation in hospitalised patients with COVID-19, with a safety profile similar to that of placebo. The added value of lenzilumab beyond other immunomodulators used to treat COVID-19 alongside steroids remains unknown.

Funding

Humanigen.

Can nebulised HepArin Reduce morTality and time to Extubation in Patients with COVID-19 Requiring invasive ventilation Meta-Trial (CHARTER-MT): Protocol and Statistical Analysis Plan for an investigator-initiated international meta-trial of prospective randomised clinical studies

There is significant interest in the potential for nebulised unfractionated heparin (UFH) as a novel therapy for patients with COVID-19 induced acute hypoxaemic respiratory failure requiring invasive ventilation. The scientific and biological rationale for nebulised heparin stems from the evidence for extensive activation of coagulation resulting in pulmonary microvascular thrombosis in COVID-19 pneumonia. Nebulised delivery of heparin to the lung may limit alveolar fibrin deposition and thereby limit progression of lung injury. Importantly, laboratory studies show that heparin can directly inactivate the SARS-CoV-2 virus, thereby prevent its entry into and infection of mammalian cells. UFH has additional anti-inflammatory and mucolytic properties that may be useful in this context. METHODS AND INTERVENTION: The Can nebulised HepArin Reduce morTality and time to Extubation in Patients with COVID-19 Requiring invasive ventilation Meta-Trial (CHARTER-MT) is a collaborative prospective individual patient data analysis of on-going randomised controlled clinical trials across several countries in 5 continents, examining the effects of inhaled heparin in patients with COVID-19 requiring invasive ventilation on various endpoints. Each constituent study will randomise patients with COVID-19 induced respiratory failure requiring invasive ventilation. Patients are randomised to receive nebulised heparin or standard care (open label studies) or placebo (blinded placebo-controlled studies) while under invasive ventilation. Each participating study collect a pre-defined minimum dataset. The primary outcome for the meta-trial is the number of ventilator-free days up to day 28 day, defined as days alive and free from invasive ventilation. ETHICS AND DISSEMINATION: The meta-trial is registered at ClinicalTrials.gov ID NCT04545541. Each contributing study is individually registered and has received approval of the relevant ethics committee or institutional review board. Results of this study will be shared with the WHO, published in scientific journals, and presented at scientific meetings.

Advancing precision medicine for acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a heterogeneous clinical syndrome. Understanding of the complex pathways involved in lung injury pathogenesis, resolution, and repair has grown considerably in recent decades. Nevertheless, to date, only therapies targeting ventilation-induced lung injury have consistently proven beneficial, and despite these gains, ARDS morbidity and mortality remain high. Many candidate therapies with promise in preclinical studies have been ineffective in human trials, probably at least in part due to clinical and biological heterogeneity that modifies treatment responsiveness in human ARDS. A precision medicine approach to ARDS seeks to better account for this heterogeneity by matching therapies to subgroups of patients that are anticipated to be most likely to benefit, which initially might be identified in part by assessing for heterogeneity of treatment effect in clinical trials. In October 2019, the US National Heart, Lung, and Blood Institute convened a workshop of multidisciplinary experts to explore research opportunities and challenges for accelerating precision medicine in ARDS. Topics of discussion included the rationale and challenges for a precision medicine approach in ARDS, the roles of preclinical ARDS models in precision medicine, essential features of cohort studies to advance precision medicine, and novel approaches to clinical trials to support development and validation of a precision medicine strategy. In this Position Paper, we summarise workshop discussions, recommendations, and unresolved questions for advancing precision medicine in ARDS. Although the workshop took place before the COVID-19 pandemic began, the pandemic has highlighted the urgent need for precision therapies for ARDS as the global scientific community grapples with many of the key concepts, innovations, and challenges discussed at this workshop.

Clinical and economic benefits of lenzilumab plus standard of care compared with standard of care alone for the treatment of hospitalized patients with COVID-19 in the United States from the hospital perspective

AIMS

Estimate the clinical and economic benefits of lenzilumab plus standard of care (SOC) compared with SOC alone in the treatment of patients hospitalized with COVID-19 pneumonia from the United States (US) hospital perspective.

MATERIALS AND METHODS

A per-patient cost calculator was developed to report the clinical and economic benefits associated with adding lenzilumab to SOC in newly hospitalized COVID-19 patients over 28 days. Clinical inputs were based on the LIVE-AIR trial, including failure to achieve survival without ventilation (SWOV), mortality, time to recovery, intensive care unit (ICU) admission, and invasive mechanical ventilation (IMV) use. Base case costs included the anticipated list price of lenzilumab, drug administration, and hospital resource costs based on the level of care required. A scenario analysis examined projected one-year rehospitalization costs.

RESULTS

In the base case and all scenarios, lenzilumab plus SOC improved all specified clinical outcomes relative to SOC alone. Lenzilumab plus SOC resulted in estimated cost savings of $3,190 per patient in a population aged <85 years with C-reactive protein (CRP) levels <150 mg/L and receiving remdesivir (base case). Per-patient cost savings were observed in the following scenarios: (1) aged <85 years with CRP <150 mg/L, with or without remdesivir ($1,858); (2) Black and African American patients with CRP <150 mg/L ($13,154); and (3) Black and African American patients from the full population, regardless of CRP level ($2,763). In the full modified intent-to-treat population, an additional cost of $4,952 per patient was estimated. When adding rehospitalization costs to the index hospitalization, a total per-patient cost savings of $5,154 was estimated.

CONCLUSIONS

The results highlight the clinical benefits for SWOV, ventilator use, time to recovery, mortality, time in ICU, and time on IMV, in addition to an economic benefit from the US hospital perspective associated with adding lenzilumab to SOC for COVID-19 patients.

Heterogeneity in design and analysis of ICU delirium randomized trials: a systematic review

BACKGROUND

There is a growing number of randomized controlled trials (RCTs) evaluating interventions to prevent or treat delirium in the intensive care unit (ICU). Efforts to improve the conduct of delirium RCTs are underway, but none address issues related to statistical analysis. The purpose of this review is to evaluate heterogeneity in the design and analysis of delirium outcomes and advance methodological recommendations for delirium RCTs in the ICU.

METHODS

Relevant databases, including PubMed and Embase, were searched with no restrictions on language or publication date; the search was conducted on July 8, 2019. RCTs conducted on adult ICU patients with delirium as the primary outcome were included where trial results were available. Data on frequency and duration of delirium assessments, delirium outcome definitions, and statistical methods were independently extracted in duplicate. The review was registered with PROSPERO (CRD42020141204).

RESULTS

Among 65 eligible RCTs, 44 (68%) targeted the prevention of delirium. The duration of follow-up varied, with 31 (48%) RCTs having ≤7 days of follow-up, and only 24 (37%) conducting delirium assessments after ICU discharge. The incidence of delirium was the most common outcome (50 RCTs, 77%) for which 8 unique statistical methods were applied. The most common method, applied to 51 of 56 (91%) delirium incidence outcomes, was the two-sample test comparing the proportion of patients who ever experienced delirium. In the presence of censoring of patients at ICU discharge or death, this test may be misleading. The impact of censoring was also not considered in most analyses of the duration of delirium, as evaluated in 24 RCTs, with 21 (88%) delirium duration outcomes analyzed using a non-parametric test or two-sample t test. Composite outcomes (e.g., rank-based delirium- and coma-free days), used in 11 (17%) RCTs, seldom explicitly defined how ICU discharge, and death were incorporated into the definition and were analyzed using non-parametric tests (11 of 13 (85%) composite outcomes).

CONCLUSIONS

To improve delirium RCTs, outcomes should be explicitly defined. To account for censoring due to ICU discharge or death, survival analysis methods should be considered for delirium incidence and duration outcomes; non-parametric tests are recommended for rank-based delirium composite outcomes.

TRIAL REGISTRATION

PROSPERO CRD42020141204 . Registration date: 7/3/2019.

LENZILUMAB EFFICACY AND SAFETY IN NEWLY HOSPITALIZED COVID-19 SUBJECTS: RESULTS FROM THE LIVE-AIR PHASE 3 RANDOMIZED DOUBLE-BLIND PLACEBO-CONTROLLED TRIAL

BACKGROUND

Severe COVID-19 pneumonia results from a hyperinflammatory immune response (cytokine storm, CS), characterized by GM-CSF mediated activation and trafficking of myeloid cells, leading to elevation of downstream inflammatory chemokines (MCP-1, IL-8, IP-10), cytokines (IL-6, IL-1), and other markers of systemic inflammation (CRP, D-dimer, ferritin). CS leads to fever, hypotension, coagulopathy, respiratory failure, ARDS, and death. Lenzilumab is a novel Humaneered® anti-human GM-CSF monoclonal antibody that directly binds GM-CSF and prevents signaling through its receptor. The LIVE-AIR Phase 3 randomized, double-blind, placebo-controlled trial investigated the efficacy and safety of lenzilumab to assess the potential for lenzilumab to improve the likelihood of ventilator-free survival (referred to herein as survival without ventilation, SWOV), beyond standard supportive care, in hospitalized subjects with severe COVID-19.

METHODS

Subjects with COVID-19 (n=520), ≥18 years, and ≤94% oxygen saturation on room air and/or requiring supplemental oxygen, but not invasive mechanical ventilation, were randomized to receive lenzilumab (600 mg, n=261) or placebo (n=259) via three intravenous infusions administered 8 hours apart. Subjects were followed through Day 28 following treatment.

RESULTS

Baseline demographics were comparable between the two treatment groups: male, 64.7%; mean age, 60.5 years; mean BMI, 32.5 kg/m2; mean CRP, 98.36 mg/L; CRP was <150 mg/L in 77.9% of subjects. The most common comorbidities were obesity (55.1%), diabetes (53.4%), chronic kidney disease (14.0%), and coronary artery disease (13.6%). Subjects received steroids (93.7%), remdesivir (72.4%), or both (69.1%). Lenzilumab improved the likelihood of SWOV by 54% in the mITT population (HR: 1.54; 95%CI: 1.02-2.31, p=0.041) and by 90% in the ITT population (HR: 1.90; 1.02-3.52, nominal p=0.043) compared to placebo. SWOV also relatively improved by 92% in subjects who received both corticosteroids and remdesivir (1.92; 1.20-3.07, nominal p=0.0067); by 2.96-fold in subjects with CRP<150 mg/L and age <85 years (2.96; 1.63-5.37, nominal p=0.0003); and by 88% in subjects hospitalized ≤2 days prior to randomization (1.88; 1.13-3.12, nominal p=0.015). Survival was improved by 2.17-fold in subjects with CRP<150 mg/L and age <85 years (2.17; 1.04-4.54, nominal p=0.040).

CONCLUSION

Lenzilumab significantly improved SWOV in hospitalized, hypoxic subjects with COVID-19 pneumonia over and above treatment with remdesivir and/or corticosteroids. Subjects with CRP<150 mg/L and age <85 years demonstrated an improvement in survival and had the greatest benefit from lenzilumab. NCT04351152.

Hyperoxia During Cardiopulmonary Bypass Is Associated With Mortality in Infants Undergoing Cardiac Surgery

OBJECTIVES

Patients undergoing cardiac surgery using cardiopulmonary bypass have variable degrees of blood oxygen tension during surgery. Hyperoxia has been associated with adverse outcomes in critical illness. Data are not available regarding the association of hyperoxia and outcomes in infants undergoing cardiopulmonary bypass. We hypothesize that among infants undergoing cardiac surgery, hyperoxia during cardiopulmonary bypass is associated with greater odds of morbidity and mortality.

DESIGN

Retrospective study.

SETTING

Single center at an academic tertiary children's hospital.

PATIENTS

All infants (< 1 yr) undergoing cardiopulmonary bypass between January 1, 2015, and December 31, 2017, excluding two patients who were initiated on extracorporeal membrane oxygenation in the operating room.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The study included 469 infants with a median age of 97 days (interquartile range, 14-179 d), weight 4.9 kg (interquartile range, 3.4-6.4 kg), and cardiopulmonary bypass time 128 minutes (interquartile range, 91-185 min). A Pao2 of 313 mm Hg (hyperoxia) on cardiopulmonary bypass had highest sensitivity with specificity greater than 50% for association with operative mortality. Approximately, half of the population (237/469) had hyperoxia on cardiopulmonary bypass. Infants with hyperoxia were more likely to have acute kidney injury, prolonged postoperative length of stay, and mortality. They were younger, weighed less, had longer cardiopulmonary bypass times, and had higher Society of Thoracic Surgeons and the European Association for Cardio-Thoracic Surgery mortality scores. There was no difference in sex, race, preoperative creatinine, single ventricle physiology, or presence of genetic syndrome. On multivariable analysis, hyperoxia was associated with greater odds of mortality (odds ratio, 4.3; 95% CI, 1.4-13.2) but failed to identify an association with acute kidney injury or prolonged postoperative length of stay. Hyperoxia was associated with greater odds of mortality in subgroup analysis of neonatal patients.

CONCLUSIONS

Hyperoxia occurred in a substantial portion of infants undergoing cardiopulmonary bypass for cardiac surgery. Hyperoxia during cardiopulmonary bypass was an independent risk factor for mortality and may be a modifiable risk factor. Furthermore, hyperoxia during cardiopulmonary bypass was associated with four-fold greater odds of mortality within 30 days of surgery. Hyperoxia failed to identify an association with development of acute kidney injury or prolonged postoperative length of stay when controlling for covariables. Validation of our data among other populations is necessary to better understand and elucidate potential mechanisms underlying the association between excess oxygen delivery during cardiopulmonary bypass and outcome.

Preemptive ganciclovir for mechanically ventilated patients with cytomegalovirus reactivation

Background

The effect of cytomegalovirus (CMV) reactivation on the length of mechanical ventilation and mortality in immunocompetent ICU patients requiring invasive mechanical ventilation remains controversial. The main objective of this study was to determine whether preemptive intravenous ganciclovir increases the number of ventilator-free days in patients with CMV blood reactivation.

Methods

This double-blind, placebo-controlled, randomized clinical trial involved 19 ICUs in France. Seventy-six adults ≥ 18 years old who had been mechanically ventilated for at least 96 h, expected to remain on mechanical ventilation for ≥ 48 h, and exhibited reactivation of CMV in blood were enrolled between February 5th, 2014, and January 23rd, 2019. Participants were randomized to receive ganciclovir 5 mg/kg bid for 14 days (n = 39) or a matching placebo (n = 37).

Results

The primary endpoint was ventilator-free days from randomization to day 60. Prespecified secondary outcomes included day 60 mortality. The trial was stopped for futility based on the results of an interim analysis by the DSMB. The subdistribution hazard ratio for being alive and weaned from mechanical ventilation at day 60 for patients receiving ganciclovir (N = 39) compared with control patients (N = 37) was 1.14 (95% CI from 0.63 to 2.06; P = 0.66). The median [IQR] numbers of ventilator-free days for ganciclovir-treated patients and controls were 10 [0–51] and 0 [0–43] days, respectively (P = 0.46). Mortality at day 60 was 41% in patients in the ganciclovir group and 43% in the placebo group (P = .845). Creatinine levels and blood cells counts did not differ significantly between the two groups.

Conclusions

In patients mechanically ventilated for ≥ 96 h with CMV reactivation in blood, preemptive ganciclovir did not improve the outcome.

Comparison of Ventilator-free Days at 14 and 28 days as a Clinical Trial Outcome in Low- and Middle-income Countries

Aims and objectives

Reporting ventilator-free days (VFDs) with time frame of 28 days is a popular composite outcome measure (COM) in trials. However, early deaths and shorter pediatric intensive care unit (PICU) stay predominate in low- and middle-income countries (LMICs). A shorter time frame may reduce sample size required. We planned to compute sample size requirements for different effect sizes from datasets of previously conducted prospective studies for 28-day and 14-day time frames (VFD₂₈ vs VFD₁₄) to examine the hypothesis.

Materials and methods

The VFD₂₈ and VFD₁₄ were defined. Datasets of five prospective studies from PICU of our hospital were analyzed to estimate sample sizes for target reductions of 1–9 days in VFDs and other COMs for the two time frames. Reconfirmation of results was done with datasets of two other studies from PICUs of two geographical extremes of the country.

Results

Time-to-event occurred within 14 days in majority of patients. Sample size required for VFD₁₄ is about one-fifth to one-sixth of what is required for VFD₂₈ for target reductions of 1–9 days for all the enrolled studies. The same was true for other COMs as well. The hypothesis was supported by datasets of two other studies used for reconfirmation.

Conclusion

Choice of time frame for assessing VFDs and other COMs in clinical trials should be guided by the clinical context. A shorter time frame may be rewarding in terms of smaller sample size in the prevalent clinical setting of LMICs. Further confirmation with more datasets and prospective studies is desirable.

How to cite this article

Baranwal AK, Kumar MP, Gupta PK. Comparison of Ventilator-free Days at 14 and 28 days as a Clinical Trial Outcome in Low- and Middle-income Countries. Indian J Crit Care Med 2020;24(10):960–966.

Composite Outcomes for Clinical Trials in Critical Care: The Devil is in the Detail

How to cite this article: Lalgudi Ganesan S, Parameswaran N. Composite Outcomes for Clinical Trials in Critical Care: The Devil is in the Detail. Indian J Crit Care Med 2020;24(10):903-904.

The promise and pitfalls of composite endpoints in sepsis and COVID-19 clinical trials

Composite endpoints reveal the tendency for statistical convention to arise locally within subfields. Composites are familiar in cardiovascular trials, yet almost unknown in sepsis. However, the VITAMINS trial in patients with septic shock adopted a composite of mortality and vasopressor-free days, and an ordinal scale describing patient status rapidly became standard in COVID studies. Aware that recent use could incite interest in such endpoints, we are motivated to flag their potential value and pitfalls for sepsis research and COVID studies.

Hydroxychloroquine versus Azithromycin for Hospitalized Patients with Suspected or Confirmed COVID-19 (HAHPS). Protocol for a Pragmatic, Open-Label, Active Comparator Trial

Coronavirus disease (COVID-19) is a potentially fatal illness with no proven therapy beyond excellent supportive care. Treatments are urgently sought. Adaptations to traditional trial logistics and design to allow rapid implementation, evaluation of trials within a global trials context, flexible interim monitoring, and access outside traditional research hospitals (even in settings where formal placebos are unavailable) may be helpful. Thoughtful adaptations to traditional trial designs, especially within the global context of related studies, may also foster collaborative relationships among government, community, and the research enterprise. Here, we describe the protocol for a pragmatic, active comparator trial in as many as 300 patients comparing two current "off-label" treatments for COVID-19-hydroxychloroquine and azithromycin-in academic and nonacademic hospitals in Utah. We developed the trial in response to local pressures for widespread, indiscriminate off-label use of these medications. We used a hybrid Bayesian-frequentist design for interim monitoring to allow rapid, contextual assessment of the available evidence. We also developed an inference grid for interpreting the range of possible results from this trial within the context of parallel trials and prepared for a network meta-analysis of the resulting data. This trial was prospectively registered (ClinicalTrials.gov Identifier: NCT04329832) before enrollment of the first patient.Clinical trial registered with www.clinicaltrials.gov (NCT04329832).

Assessing the Course of Organ Dysfunction Using Joint Longitudinal and Time-to-Event Modeling in the Vasopressin and Septic Shock Trial

Supplemental Digital Content is available in the text.

Non-mortality septic shock outcomes (e.g., Sequential Organ Failure Assessment score) are important clinical endpoints in pivotal sepsis trials. However, comparisons of observed longitudinal non-mortality outcomes between study groups can be biased if death is unequal between study groups or is associated with an intervention (i.e., informative censoring). We compared the effects of vasopressin versus norepinephrine on the Sequential Organ Failure Assessment score in the Vasopressin and Septic Shock Trial to illustrate the use of joint modeling to help minimize potential bias from informative censoring.

Contemporary strategies to improve clinical trial design for critical care research: insights from the First Critical Care Clinical Trialists Workshop

BACKGROUND

Conducting research in critically-ill patient populations is challenging, and most randomized trials of critically-ill patients have not achieved pre-specified statistical thresholds to conclude that the intervention being investigated was beneficial.

METHODS

In 2019, a diverse group of patient representatives, regulators from the USA and European Union, federal grant managers, industry representatives, clinical trialists, epidemiologists, and clinicians convened the First Critical Care Clinical Trialists (3CT) Workshop to discuss challenges and opportunities in conducting and assessing critical care trials. Herein, we present the advantages and disadvantages of available methodologies for clinical trial design, conduct, and analysis, and a series of recommendations to potentially improve future trials in critical care.

CONCLUSION

The 3CT Workshop participants identified opportunities to improve critical care trials using strategies to optimize sample size calculations, account for patient and disease heterogeneity, increase the efficiency of trial conduct, maximize the use of trial data, and to refine and standardize the collection of patient-centered and patient-informed outcome measures beyond mortality.