Inhaled Nitric Oxide for the Adjunctive Therapy of Severe Malaria: a Randomized Controlled Trial

Despite the use of highly effective anti-malarial medications, 10-30% of African children with severe malaria will die, underscoring the need for adjunctive therapies that can be applied in endemic areas. A clinical trial of adjunctive inhaled nitric oxide (iNO) in severe malaria is warranted on the basis of firm proof of concept from animal studies and a human study using the NO donor L-arginine, together with evidence of safety from clinical experience and trials of iNO for other conditions. Our objective is to determine whether supplemental iNO (80 ppm) in addition to Ugandan Standard of Care treatment reduces levels of Angiopoietin-2 (Ang-2), a quantitative biomarker of malaria severity, in children with severe malaria compared to Standard of Care treatment alone. We will conduct a randomized placebo-controlled trial among children 1-10 years of age admitted to Jinja Hospital (Uganda) with severe malaria to test the efficacy of inhaled nitric oxide in severe malaria.

Severe malaria remains a major cause of global morbidity and mortality. While the use of artemisinin-based antimalarial therapy has improved outcomes in severe malaria, the mortality rate remains high. Adjunctive therapies that target the underlying pathophysiology of severe malaria may further reduce morbidity and mortality. Endothelial activation plays a central role in the pathogenesis of severe malaria, of which the angiogenic factors angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) have recently been shown to function as key regulators. Nitric oxide (NO) is a major inhibitor of Ang-2 release from endothelium and has been shown to decrease endothelial inflammation and reduce the adhesion of parasitized erythrocytes. Low-flow inhaled nitric oxide gas (iNO) is a US FDA-approved treatment for hypoxic respiratory failure in neonates. Based on compelling data on the efficacy of iNO in experimental cerebral malaria in animal models, coupled with the documented safety of iNO in clinical practice and trials for other diseases, we propose a randomized clinical trial of iNO for the adjunctive treatment of severe malaria in Ugandan children.

iNO, a gaseous molecule, will be administered by inhalational route over a maximum period of 72 hours.

Form: Gas (inhalational) Dose: 80 ppm Dosing schedule: Continuous Treatment period: Maximum 72 hours (may be discontinued earlier if patient recovers and no longer tolerates face mask)

Daily Ang-2 measurements over the first 72 hours of hospital admission will be the primary efficacy outcome. Elevated Ang-2 levels are associated with poor clinical outcome in severe malaria and Ang-2 has been used to follow disease progression and recovery in previous studies of malaria. Thus, Ang-2 is an objective, quantitative surrogate marker of disease severity, validated for longitudinal follow-up of patients with malaria.

Recovery times (time to fever resolution, time to sit unsupported, and time to hospital discharge) are standard, clinically relevant outcomes in other therapeutic trials for malaria.

Parasitological efficacy outcome; quantitative assessment of parasite density by light microscopy of Giemsa-stained thin smears.

Biomarkers and genetic determinants of endothelial activation, inflammation and coagulopathy, to be determined.

Biomarkers and genetic determinants of severe malaria pathogenesis may provide additional insight into the pathways and processes altered in cerebral malaria and affected by iNO delivery. We plan to examine biomarkers of endothelial activation, inflammation including cytokines, and coagulopathy which are central to the pathophysiology of severe malaria. In addition, genetic pathways involved in severe malaria and response to iNO will be investigated.

Inclusion Criteria: Age 1-10 years Positive malaria rapid diagnostic test in the presence of any of the features of severe malaria Willing and able to complete follow up schedules for the study - 14 day and 6 months after hospital discharge Exclusion Criteria: Baseline methemoglobinemia Known renal, cardiac, or hepatic disease or other chronic illnesses like diabetes, epilepsy, cerebral palsy, clinical AIDS Severe malnutrition Severe malarial anemia without other signs of severe malaria

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