Co-administration of nitric oxide-aspirin (NCX-4016) and aspirin prevents platelet and monocyte activation and protects against gastric damage induced by aspirin in humans

OBJECTIVES The goal of this study was to test the hypothesis that NCX-4016 may have broader anti-inflammatory and antithrombotic effects as well as better gastric tolerability than aspirin in humans. BACKGROUND NCX-4016 is an aspirin derivative containing a nitric oxide-releasing moiety that prevents platelet activation and modulates tissue factor (TF) expression and cytokine release from lipopolysaccharide (LPS)-stimulated monocytes. METHODS This was a blind-observer, placebo-controlled, parallel-group study in which 48 healthy subjects were randomized to receive NCX-4016 800 mg twice a day, NCX-4016 800 mg twice a day plus aspirin 325 mg, aspirin 325 mg, or placebo for 21 days. RESULTS Similar to aspirin alone, NCX-4016 effectively inhibited platelet aggregation induced by 0.6 mmol/l arachidonic acid, clot-stimulated thromboxane (TX) B-2 generation in whole blood, and urinary excretion of 11-dehydro-TXB2. Unlike aspirin alone, the administration of NCX-4016 significantly inhibited TF expression in monocytes stimulated ex vivo with 10 mumol/l LPS (determined by flow-cytometry analysis of TF on CD14 positive cells). NCX-4016 also inhibited the rapid TF expression induced in monocytes by a proteinase activated receptor agonist (thrombin receptor activator protein, 2 mumol/l) as well as LPS-induced expression of CD11b. Ex vivo, release of MCP-1 and interleukin-6 were significantly inhibited by NCX-4016, but not by aspirin. NCX-4016 was not associated with gastric damage, and significantly reduced gastric injury when co-administered with aspirin, although both drugs reduced gastric PGE(2) production to the same extent. CONCLUSIONS NCX-4016 is equally effective as aspirin in inhibiting cyclooxygenase activity. However, NCX-4016 causes less gastric damage and prevents monocyte activation. Larger multicenter trials are warranted to establish clinical efficacy and safety of NCX-4016. (C) 2004 by the American College of Cardiology Foundation.