The rate of adverse events was similar across the four groups , with serious adverse events occurring in seven ( 2 % ) of 329 patients in the tofacitinib 5 mg group , five ( 2 % ) of 330 in the tofacitinib 10 mg group , seven ( 2 % ) of 335 in the etanercept group , and two ( 2 % ) of 107 in the placebo group .