Adverse events in the first @ weeks of treatment led to discontinuation of simeprevir in two ( < @ % ) patients and discontinuation of placebo in one patient ( < @ % ) ; fatigue ( @ -LSB- @ % -RSB- vs @ -LSB- @ % -RSB- patients , respectively ) and headache ( @ -LSB- @ % -RSB- vs @ -LSB- @ % -RSB- , respectively ) were the most common adverse events .