Skip to content

Safety and Efficacy Study of Inhaled Carbon Monoxide to Treat Acute Respiratory Distress Syndrome (ARDS)

A Phase II Trial of Inhaled Carbon Monoxide for the Treatment of Acute Respiratory Distress Syndrome (ARDS)

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03799874
Enrollment
4
Registered
2019-01-10
Start date
2019-09-30
Completion date
2021-04-13
Last updated
2026-06-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Acute Respiratory Distress Syndrome

Brief summary

This study will be a multi-center, prospective, randomized, partially double-blind, placebo-controlled Phase II clinical trial of inhaled CO (iCO) for the treatment of ARDS. The trial will be conducted at 7 tertiary care medical centers including Weill Cornell Medicine/NewYork-Presbyterian Hospital, Brigham and Women's Hospital (BWH), Massachusetts General Hospital (MGH), Duke University Hospital, Durham Veterans Administration Medical Center, New York-Presbyterian Brooklyn Methodist Hospital, and Duke Regional Hospital. The purpose of this study is to evaluate the safety, tolerability, and efficacy of inhaled carbon monoxide (iCO) for the treatment of ARDS and to examine the biologic readouts of low dose iCO therapy in patients with ARDS

Detailed description

Acute respiratory distress syndrome (ARDS) is a devastating disease affecting military, veteran, and civilian populations. ARDS is a syndrome of severe acute lung inflammation and hypoxemic respiratory failure with an incidence of 180,000 cases annually in the United States. Despite recent advances in critical care management and lung protective ventilation strategies, ARDS morbidity and mortality remain unacceptably high. The lack of specific effective therapies for ARDS indicates a need for new treatments that target novel pathways. Carbon monoxide (CO) represents a novel therapeutic modality in ARDS based on data obtained in experimental models of ARDS over the past decade. CO has been shown to be protective in experimental models of acute lung injury (ALI) and sepsis. Furthermore, multiple human studies have demonstrated that experimental administration of several different concentrations of CO is well tolerated and that low dose inhaled CO can be safely administered to subjects in a controlled research environment. The investigators have previously conducted a Phase I trial of low dose iCO in ARDS which demonstrated that precise administration of low dose iCO (100 and 200 ppm) is feasible, well-tolerated, and safe in patients with sepsis-induced ARDS. The purpose of this study is to assess the safety and efficacy of low dose inhaled carbon monoxide (iCO) therapy in mechanically ventilated patients with ARDS.

Interventions

DRUGInhaled Carbon Monoxide at 200 ppm

Inhaled Carbon Monoxide at 200 ppm for 90 minutes daily for 3 days.

Inhaled Medical Air for up to 90 minutes daily for 3 days.

Sponsors

Brigham and Women's Hospital
Lead SponsorOTHER
Massachusetts General Hospital
CollaboratorOTHER
Weill Medical College of Cornell University
CollaboratorOTHER
Duke University
CollaboratorOTHER
Durham VA Medical Center
CollaboratorFED
New York Presbyterian Brooklyn Methodist Hospital
CollaboratorOTHER
Duke Regional Hospital
CollaboratorOTHER
U.S. Army Medical Research Acquisition Activity
CollaboratorFED
Washington University School of Medicine
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)

Masking description

The study drug will be blinded to the study staff using identical tanks containing either CO or placebo air. The administering respiratory therapist (RT) and a physician study staff member will be unblinded to the treatment assignments.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

All intubated patients ≥ 18 years old with ARDS 1. ARDS is defined when all four of the following criteria are met: 1. A PaO2/FiO2 ratio ≤ 300 with at least 5 cm H2O positive end-expiratory airway pressure (PEEP) 2. Bilateral opacities on frontal chest radiograph (not fully explained by effusions, lobar/lung collapse, or nodules) within 1 week of a known clinical insult or new or worsening respiratory symptoms 3. A need for positive pressure ventilation by an endotracheal or tracheal tube 4. Respiratory failure not fully explained by cardiac failure or fluid overload; need objective assessment (e.g., echocardiography) to exclude hydrostatic edema if no risk factor present. 2. ARDS onset is defined as the time the last of criteria 1-4 are met. ARDS must persist through the enrollment time window of 168 hours.

Exclusion criteria

An individual who meets any of the following criteria will be excluded from participation in this study: 1. Age less than 18 years 2. Greater than 168 hours since ARDS onset 3. Pregnant or breastfeeding 4. Prisoner 5. Patient, surrogate, or physician not committed to full support (exception: a patient will not be excluded if he/she would receive all supportive care except for attempts at resuscitation from cardiac arrest) 6. No consent/inability to obtain consent or appropriate legal representative not available 7. Physician refusal to allow enrollment in the trial 8. Moribund patient not expected to survive 24 hours 9. No arterial or central line/no intent to place an arterial or central line 10. No intent/unwillingness to follow lung protective ventilation strategy 11. Severe hypoxemia defined as SpO2 \< 95 or PaO2 \< 90 on FiO2 ≥ 0.9 12. Hemoglobin \< 7.0 g/dL 13. Subjects who are Jehovah's Witnesses or are otherwise unable or unwilling to receive blood transfusions during hospitalization 14. Acute myocardial infarction (MI) or acute coronary syndrome (ACS) within the last 90 days 15. Coronary artery bypass graft (CABG) surgery within 30 days 16. Angina pectoris or use of nitrates with activities of daily living 17. Cardiopulmonary disease classified as NYHA class IV 18. Stroke (ischemic or hemorrhagic) within the prior 1 month, cardiac arrest requiring CPR within the prior 72 hours, or inability to assess mental status following cardiac arrest 19. Burns \> 40% total body surface area (TBSA) 20. Severe airway inhalational injury 21. Use of high frequency oscillatory ventilation 22. Use of extracorporeal membrane oxygenation (ECMO) 23. Concomitant use of inhaled pulmonary vasodilator therapy (eg. nitric oxide \[NO\] or prostaglandins) 24. Diffuse alveolar hemorrhage from vasculitis 25. Concurrent participation in other investigational drug study

Design outcomes

Primary

MeasureTime frameDescription
Primary Safety Outcome: Number of Pre-specified Administration-related Adverse Events.7 daysSafety of inhaled CO, defined by the incidence of pre-specified administration-related AEs (as defined below) and spontaneously reported AEs through study day 7. 1. Acute MI within 48 hours of study drug administration 2. Acute cerebrovascular accident (CVA) within 48 hours of study drug administration 3. New onset atrial or ventricular arrhythmia requiring DC cardioversion within 48 hours of study drug administration 4. Increased oxygenation requirements defined as: an increase in FiO2 of ≥ 0.2 AND increase in PEEP ≥ 5 cm H2O within 6 hours of study drug administration 5. Increase in COHb ≥ 10% 6. Increase in lactate by ≥ 2 mmol/L within 6 hours of study drug administration
Primary Efficacy Outcome: Change in Mitochondrial DNA (mtDNA) Level From Day 1 to Day 55 daysMitochondrial DNA (mtDNA) plasma levels will be measured by quantitative PCR of human NADH dehydrogenase 1. The number presented is the percentage average difference from beginning to end of treatment. Limited number of measurements prevents variance analyses; therefore we present the data from the subjects available in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.

Secondary

MeasureTime frameDescription
Lung Injury Score (LIS) on Days 1-5, and on Days 1-77 daysThe Lung Injury Score (LIS) is a composite 4-point scoring system including the PaO2/FiO2, PEEP, quasi-static respiratory compliance, and the extent of infiltrates on the chest X-ray. Each of the four components is categorized from 0 to 4, where a higher number is worse. The total Lung Injury Score is obtained by dividing the aggregate sum by the number of components used. Previous randomized clinical trials in ARDS have shown that a decreased LIS correlates with improvement in lung physiology as well as important clinical outcomes including mortality and ventilator-free days (VFDs). The number presented is the average difference from beginning to end of treatment. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Percent Change in PaO2/FiO2 Ratio on Days 1-5, and on Days 1-77 daysPaO2/FiO2 will be measured daily on days 1-5 and days 1-7 in ventilated subjects. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Percent Change in Oxygenation Index (OI) on Days 1-5, and Days 1-77 daysThe oxygenation index will be measured on days 1-5 and on days 1-7 in ventilated subjects. Oxygenation index is calculated as (FiO2 X mean airway pressure)/PaO2. We provide change in Oi from baseline. Oi is only measured when subjects are ventilated, therefore not all timepoints are available. The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Percent Change in Dead Space Fraction (Vd/Vt) on Days 1-3, and Days 1-77 daysThe dead space fraction will be measured days 1-3 and days 1-7 in ventilated subjects. We present change in dead space fraction between initial and final measurements that were available (measurements only taken while the subjects were intubated). The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Percent Change in Sequential Organ Failure Assessment (SOFA) Score on Days 1-5, and Days 1-7.1-5 and 1-7 daysOrgan failure will be assessed using the SOFA score. SOFA scores will be assessed daily on days 1-5 and day 7, as the SOFA score has been shown to be a reliable prognostic indicator of outcomes in critically ill patients. To calculate the Sequential Organ Failure Assessment (SOFA) score, each of the six components (Respiratory, Coagulation, Liver, Cardiovascular, Central Nervous System, Renal) is categorized from 0-4, where a higher number is worse. The SOFA score (0-24) will be calculated by summing all six components. We present changes in SOFA score over the time of hospitalization, over the time of ICU admission (up to days 5 and 7 for the enrolled subjects). The limited number of measurements prevent the variance and measures of dispersion calculations; therefore we present the average of data from the available subjects in each group and report as "Mean" without standard deviation, where measures of dispersion cannot be calculated.
Absolute Value of Biomarkers of Inflammation and Inflammasome Activation4 daysCytokine plasma levels (eg. IL-1B) will be measured by ELISA daily on days 1-3 and on day 4. We report the absolute Mean Fluorescent Intensity (MFI) of each sample at pretreatment time point of day 4. Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number" without standard deviation, since measures of dispersion cannot be calculated.
Percent Change in Lipid Mediators4 daysLipid mediators (LM) and specialized pro-resolving mediators (SPMs) will be measured in plasma using liquid chromatography-tandem mass spectrometry (LC-MS-MS) based methods daily on days 1-3 and on day 4. The percentage change from baseline at day 1 to post treatment at day 4 is reported. A representative LM is shown (14-HDHA (14-hydroxy-4Z,7Z,10Z,12E,16Z,19Z-docosahexaenoic acid) is an oxidized metabolite of omega-3 docosahexaenoic acid (DHA)). Limited number of measurements prevents variance and measures of dispersion analyses; therefore we present the data from the subjects available in each group and report as "Number" without standard deviation, since measures of dispersion cannot be calculated.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORRebecca Baron, MD

Brigham and Women's Hospital

Participant flow

Recruitment details

First recruited subject date was 9/30/2019 and last recruited subject was 4/5/2021. The study treatment was 3 days and follow up during 60 days during hospitalization and up to 6 months follow up. Screening was conducted in Intensive Care Units and qualifying subjects were consented by study physicians at Brigham and Women's Hospital, Duke University Hospital and New York Presbyterian Brooklyn Methodist Hospital.

Pre-assignment details

After consent. Subjects were randomized to either placebo or inhaled CO. Study procedures started the following day after randomization. The study recruited a total of 4 subjects and was closed due to low enrollment.

Baseline characteristics

Characteristic
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
4 Participants
Baseline Critical Illness: Acute Respiratory Distress Syndrome (ARDS)4 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
1 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
1 Participants
Race (NIH/OMB)
Black or African American
0 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants
Race (NIH/OMB)
White
2 Participants
Sex: Female, Male
Female
3 Participants
Sex: Female, Male
Male
1 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
2 / 30 / 1
other
Total, other adverse events
0 / 31 / 1
serious
Total, serious adverse events
3 / 31 / 1

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 17, 2026