knew which medication was being given. trial 3 enrolled participants in whom dmards did not work well. participants were randomly assigned to receive one of two doses of upadacitinib or placebo daily by mouth in addition to dmards for 12 weeks. at week 12, participants who received placebo were reassigned to upadacitinib daily. neither the subject nor the healthcare providers knew which medication was being given. trial 4 enrolled participants in whom methotrexate did not work well. participants were randomly assigned to receive upadacitinib or placebo daily by mouth in addition to methotrexate for 14 weeks. participants receiving placebo who did not have adequate improvement of signs and/or symptoms could be switched to upadacitinib after week 14. at week 26, all participants receiving placebo were switched to upadacitinib once daily by mouth. neither the subject nor the healthcare providers knew which medication was being given. trial 5 enrolled participants in whom dmards did not work well or could not be tolerated. participants were randomly assigned to receive one of two doses of upadacitinib or placebo treatment daily added to dmards for 12 weeks. at week 12, participants who received placebo were reassigned to upadacitinib daily. the benefit of upadacitinib was measured by comparing the proportion of participants treated with upadacitinib who achieved an american college of rheumatology 20 (acr20) response at week 12 or week 14 to the proportion of participants treated with mtx or placebo who achieved an acr20 response. acr20 is a 20% improvement in signs and symptoms of ra. upadacitinib was approved for medical use in the european union in december 2019. in february 2023, upadacitinib was approved in the uk for treatment of crohn's disease. in april 2023, upadacitinib was approved in the eu for the treatment of moderately to severely active crohn's disease in adults. the approval was for adults who "had an inadequate response, lost response or were intolerant to conventional therapy or a biological agent". research upadacitinib has also demonstrated success in treating moderate to severe atopic dermatitis which it has been fda approved to treat and has been found to have superior efficacy compared with placebo and dupilumab.