Publication of real-world data from a retrospective study on the use of INOmax in hospitalized COVID-19 patients with ARDS

The results of the study were published in the peer-reviewed journal Drugs in Context.

The safety and efficacy of INOmax to treat COVID-19 have not been evaluated, established or approved for use by the FDA. The retrospective, observational medical chart review study included patients who were at least 18 years old at the time of hospitalization, hospitalized for COVID-19, met the Berlin definition of ARDS, received INOmax for at least 24 hours continuously during hospitalization and had a partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio (P/F ratio) greater than 100 and less than 300mmHg when INOmax was initiated.

A total of 213 patients were screened for enrollment from seven study sites across the U.S. of which 37 patients met enrollment criteria. Patients were followed from COVID-19–related hospitalization up to 30 days post discharge or until loss to follow-up, and data were collected between October 1, 2020, and March 31, 2021. The most common reason for exclusion was severe ARDS with a P/F ratio less than 100 (N=146; 83 percent of excluded patients).

The data analysis found that when response was defined as an increase in P/F ratio by greater than 20 percent at any time after INOmax initiation, nearly two-thirds of patients (n=23; 62.2 percent) achieved response to INOmax. Additionally, mean P/F ratio (standard deviation) increased from 136.7 (34.4) at baseline to 140.3 (53.2) at 48 hours and 151.8 (50.0) at 72 hours after INOmax initiation (N=34). Median time to response was 3 days (interquartile range 1 to 3 days) after initiation of INOmax. In a sensitivity analysis, when response was defined as a greater than 10 percent increase in P/F ratio, most (n=26; 70.3 percent) patients were categorized as responders. Among the 27 patients (73 percent) receiving invasive mechanical ventilation at the time of INOmax initiation, 4 (14.8 percent) were transitioned to non-invasive ventilation. No patient required extracorporeal membrane oxygenation (ECMO) after initiating INOmax.

Data on select adverse events of interest were also collected (methemoglobinemia, airway injury and worsening pulmonary edema) and none were attributed to INOmax treatment. At discharge, 20 patients (54 percent) improved or remained stable according to the Clinical Global Impression–Improvement (CGI-I) scores.

Study limitations include the retrospective nature of the study design and the use of data abstracted from medical charts of study patients. The accuracy and completeness of data in this study are limited by the availability and quality of data in each patient's medical chart. Treatment patterns in the study reflect the use of INOmax for hospitalized COVID-19 patients in selected medical centers willing to participate in this retrospective medical chart study and may not be representative of all institutions using INOmax. The dosing and duration of INOmax treatment was variable across sites and determined at the attending physician's discretion. Criteria for initiation of INOmax, INOmax weaning and weaning protocols were not standardized across sites. Detailed information was not collected about all potential interventions for the acute management of COVID-19 ARDS, including diuretics, vasopressors and prone positioning.

Future randomized, placebo-controlled studies are needed to determine potential efficacy, safety and place in therapy. Due To The Retrospective Nature Of This Analysis, It Is Hypothesis-Generating; No Formal Conclusions Should Be Drawn.

See- "Real-world use of inhaled nitric oxide therapy in patients with COVID-19 and mild-to-moderate acute respiratory distress syndrome."-Authors: Steven H Abman, Nicholas R Fox, M Ibrahim Malik, et al.,, on behalf of the NOTICE Study Investigators DOI(Drugs in Context) 10.7573/dic.2022-1-4.