Post hoc analysis of patients with rheumatoid arthritis under clinical remission in two Japanese Phase 3 trials of peficitinib treatment (RAJ3 and RAJ4)

OBJECTIVE

We evaluated remission rates and their relationship with baseline characteristics in patients with rheumatoid arthritis treated with the oral Janus kinase inhibitor peficitinib.

METHODS

This post hoc analysis of data from two Phase 3 studies (RAJ3 and RAJ4) of peficitinib (100 and 150 mg/day) in Asian rheumatoid arthritis patients investigated clinical disease activity index (CDAI) remission and low disease activity rates from baseline to Week 52. CDAI, Health Assessment Questionnaire-Disability Index, and van der Heijde-modified total Sharp score remission/low disease activity rates at Week 52 were evaluated among patients achieving CDAI remission at Weeks 12/28. Logistic regression analyses explored the relationship between baseline characteristics and CDAI remission/low disease activity rates.

RESULTS

CDAI remission rates increased over time in a dose-dependent manner in both peficitinib-treated groups. Most patients achieving CDAI remission at Weeks 12/28 also achieved remission at Week 52. Following the multivariate analysis of demographic and baseline characteristics, factors associated with the achievement of CDAI remission at Week 28 included male sex, low baseline prednisone dose (RAJ3 only), and low baseline Disease Activity Score 28-C-reactive protein (RAJ4 only).

CONCLUSIONS

Peficitinib demonstrated persistent efficacy in clinical remission to Week 52. Baseline characteristics associated with CDAI remission were mostly consistent with previous studies using other disease-modifying antirheumatic drugs.

Safety and effectiveness of peficitinib 100 mg/day in patients achieving clinical remission from a long-term open-label extension study in Japan, Korea, and Taiwan (RAJ2)

OBJECTIVES

This post hoc analysis of the RAJ2 study assessed long-term safety and effectiveness of peficitinib 100 mg/day for treatment of rheumatoid arthritis.

METHODS

Eligible patients previously completed two Phase 3 (RAJ3 and RAJ4) studies of peficitinib in Asia. All patients received peficitinib 100 mg/day at RAJ2 Week (W)0; dose change to 50 mg/day or 150 mg/day was permitted. Safety endpoints included treatment-emergent adverse events and laboratory test results. Effectiveness endpoints included peficitinib exposure pattern, achievement of Clinical Disease Activity Index (CDAI) remission by peficitinib exposure pattern at W0 and W48, and association of demographics/characteristics with CDAI remission at W0 and W48.

RESULTS

Overall, no new safety findings were reported at W48, and renal function was unaffected. Of patients included in effectiveness analyses at W48, 70.9% (451/636) had maintained peficitinib 100 mg/day since W0. Of patients who achieved CDAI remission at W0 and maintained peficitinib 100 mg/day to W48, 50.3% (79/157) maintained CDAI remission to W48. Low disease activity and a lower number of prior disease-modifying antirheumatic drugs were significantly associated with CDAI remission at W48.

CONCLUSIONS

Long-term peficitinib treatment at a dose of 100 mg/day was generally well tolerated and, following induction therapy, maintained effectiveness through to W48.