A Study to Evaluate the Effect of Losmapimod on Cardiac Conduction as Compared to Placebo and Moxifloxacin

This will be a double-blind, 4-period, randomized, cross-over study conducted in healthy adult subjects. The purpose of this study is to characterize the effect of orally administered losmapimod on the electrocardiogram (ECG) parameters with a focus on cardiac repolarization as measured by the corrected QT interval (QTc) duration, compared with placebo and moxifloxacin. Moxifloxacin (Avelox) is a drug with a known potential to create a mild QTc interval prolongation; therefore, it will serve as a positive control to validate the ability of this study to detect a change in the QTc interval. All subjects will participate in 4 study periods separated by a minimum washout period of 5 days. Each subject will receive one of 4 regimens (A = Losmapimod 7.5 milligram \[mg\] Twice daily \[BID\] x 5 days, B = Losmapimod 20 mg Once daily \[QD\] x 5 days, C = moxifloxacin 400 mg on Day 5, D = Losmapimod matched placebo and moxifloxacin placebo x 5 days) in each of the 4 planned study periods in a randomized, cross-over fashion. Subjects will be assigned to one of four treatment sequences following a Williams design (ABDC, BCAD, CDBA, DACB). Follow-up visit will occur 10 to 14 days after end of Period 4