The study is a First-in-Human, Phase I, randomized, double-blind, placebo-controlled study evaluating single and multiple ascending oral doses of GLPG2451 and combined multiple doses of GLPG2451 and GLPG2222 in healthy female subjects. The purpose of the study is to evaluate safety and tolerability after single ascending oral doses and of multiple doses of GLPG2451 given to healthy female subjects compared to placebo as well as of multiple doses of the combination of GLPG2451/GLPG2222 compared to GLPG2451/placebo.