Adverse events occurred in @ ( @ % ) of @ patients in the etrolizumab @ mg group ( five -LSB- @ % -RSB- of which were regarded as serious ) , @ ( @ % ) of @ patients in the etrolizumab @ mg plus LD group ( two -LSB- @ % -RSB- serious ) , and @ ( @ % ) of @ patients in the placebo group ( five -LSB- @ % -RSB- serious ) .