Patient Disease Trajectories in Rheumatoid Arthritis Patients Treated with Baricitinib 4-mg in Four Phase 3 Clinical Studies

IntroductionWe sought to identify and compare treatment response groups based on individual patient responses (rather than group mean response) over time on the Clinical Disease Activity Index (CDAI) for rheumatoid arthritis (RA), in patients treated with baricitinib 4-mg in 4 phase 3 studies.MethodsTrajectory subgroups were identified within each study using growth mixture modeling. Following grouping, baseline characteristics and disease measures were summarized and compared.ResultsIn each study, three response trajectories were identified. In the three studies of patients naive to biological disease-modifying anti-rheumatic drugs (bDMARDs) patients had, on average, high disease activity, as measured by CDAI. In these studies, a group of rapid responders (65-71% of patients) had the lowest baseline CDAI scores and achieved mean CDAI <= 10 by week 16. Gradual responders (10-17%) had higher baseline CDAI, but generally achieved low disease activity (CDAI <= 10) by week 24. A group of partial responders (18-22%) had higher baseline CDAI and did not achieve mean CDAI <= 10. In bDMARD-experienced patients, the subgroups were rapid responders, who achieved mean CDAI <= 10 (42% of patients); partial responders, with mean CDAI decrease of similar to 15 points from baseline (42% of patients); and limited responders (15% of patients). Changes in modified total sharp score (mTSS; assessed only in biologic-naive patients) were below the smallest detectable difference at 24/52 weeks for > 90% of patients in each group, excepting partial responders in RA-BEGIN (>= 75% no detectable change).ConclusionIn patients receiving baricitinib 4-mg, lower baseline CDAI was generally associated with rapid response, while higher baseline CDAI scores were generally seen for patients who either reached treatment targets more gradually, or who had a partial or limited response. Maintenance of response was observed with continued baricitinib treatment in all response groups and generally included maintenance of mTSS.

Automated summary

This study aimed to analyze and compare treatment response groups based on individual patient responses over time on the Clinical Disease Activity Index for rheumatoid arthritis in patients treated with baricitinib. Three response trajectories were identified in each study, and different patient groups were observed based on their baseline disease activity and treatment response. Baricitinib treatment was found to effectively maintain response in all response groups.