The purpose of this study is to see if filgotinib can be useful to treat your RA in combination with your current dose of Methotrexate (MTX).

This is a randomized, double-blind, placebo- and active-controlled study. Randomized means the study treatment you take will be chosen by chance--like flipping a coin. Double- blind means that you and your study doctor will not know what study drug you are taking. Placebo-controlled means that you may be taking a tablet or injection with no medicine in it; the placebo tablets look like the filgotinib tablets for this study and the placebo injections look like the adalimumab injections for this study.