Efficacy and Safety of GSK3196165 Versus Placebo and Tofacitinib in Participants With Moderately to Severely Active Rheumatoid Arthritis Who Have an Inadequate Response to Methotrexate

This study \[contRAst 1 (201790: NCT03980483)\] is a phase 3, randomized, multicenter, double blind study to assess the safety and efficacy of GSK3196165, in combination with methotrexate (MTX), for the treatment of adult participants with moderate to severe active rheumatoid arthritis (RA) who have had an inadequate response to MTX. The study will consist of a screening phase of up to 6 weeks followed by a 52-week treatment phase in which participants will be randomized in a ratio of 6:6:3:1:1:1 to receive GSK3196165 150 milligrams (mg) subcutaneous (SC) weekly, GSK3196165 90 mg SC weekly, tofacitinib capsules (cap) 5 mg twice a day or placebo (three arms, each placebo arm will have 12 weeks placebo followed by 40 weeks active treatment) respectively, all in combination with MTX. Participants who, in investigator's judgement will benefit from extended treatment with GSK3196165, may be included in the long-term extension study \[contRAst X (209564: NCT04333147)\]. For those participants who do not continue into the long term-extension study, there will be an 8 week safety follow-up visit following the treatment phase.