Safety and Preliminary Efficacy of L-arginine in Severe Falciparum Malaria

Summary

Background: Mortality from severe malaria remains \~15% despite the use of the most rapidly parasiticidal antimalarial therapy, artesunate. Adjunctive treatments may improve outcome. Our overall goal is to determine if adjunctive treatment with L-arginine is safe and improves outcomes in severe malaria. In studies to date, we have shown that L-arginine is safe in moderately severe malaria, increases nitric oxide production and improves endothelial function. We now propose to extend these studies to patients with severe malaria. Aims: To determine the safety, preliminary efficacy, pharmacokinetics and pharmacodynamics of L-arginine infusion in severe malaria. Hypothesis: L-arginine will improve endothelial function, lactate clearance time and tissue oxygen delivery compared to saline with no clinically significant adverse effects. Methods: Based on previous pharmacokinetic modeling and simulations, we propose a phase 2A randomised controlled trial of L-arginine vs saline in severe malaria, each given over 8 hours. If safety is demonstrated this will be followed by a phase 2B open-label study of 24-hour infusion of L-arginine in severe malaria with safety and preliminary efficacy compared with the 8 hour infusions given in phase 2A. The primary outcomes will be the improvement in endothelial function and lactate clearance in patients given L-arginine infusion compared with those who received saline. Among the secondary outcomes will be safety and the effect of L-arginine vs saline on tissue oxygen delivery (NIRS). Data from both phase 2A and 2B will be used to generate a pharmacokinetic/ pharmacodynamic model.

Timeline

Start

2008-02

Primary completion

2009-03

Completion

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Publications

• Background Yeo TW, Lampah DA, Gitawati R, Tjitra E, Kenangalem E, McNeil YR, Darcy CJ, Granger DL, Weinberg JB, Lopansri BK, Price RN, Duffull SB, Celermajer DS, Anstey NM. Impaired nitric oxide bioavailability and L-arginine reversible endothelial dysfunction in adults with falciparum malaria. J Exp Med. 2007 Oct 29;204(11):2693-704. doi: 10.1084/jem.20070819. Epub 2007 Oct 22.
• Yeo TW, Lampah DA, Rooslamiati I, Gitawati R, Tjitra E, Kenangalem E, Price RN, Duffull SB, Anstey NM. A randomized pilot study of L-arginine infusion in severe falciparum malaria: preliminary safety, efficacy and pharmacokinetics. PLoS One. 2013 Jul 29;8(7):e69587. doi: 10.1371/journal.pone.0069587. Print 2013.

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