The primary objective of this thorough QT/QTc study was to investigate whether once-daily administration of therapeutic ( 2.5 / 1.5 mg ) and supratherapeutic ( 12.5 / 7.5 mg ) doses of NOMAC/E2 were associated with prolongation of the mean Fridericia-corrected QT ( QTcF ) interval in electrocardiograms at steady-state concentrations of NOMAC/E2 versus placebo .