18A109

EFFECTS OF BARICITINIB ON PATIENTS WHO STOP METHOTREXATE MONOTHERAPY AND SWITCH TO BARICITINIB MONOTHERAPY

Author(s)

Roy Fleischmann1, Tsutomu Takeuchi2, Michael Schiff3, Doug Schlichting4, Li Xie4, Maher Issa4, Ivaylo Stoykov4, Jeff Lisse4, Pindaro Martinez-Osuna4, Terence Rooney4, Cristiano A.F. Zerbini5, Erica Tierney (Presenter only)6

Department(s)/Institutions

1Metroplex Clinical Research Center, Dallas, USA; 2Keio University School of Medicine, Tokyo, Japan; 3University of Colorado, Denver, USA; 4Eli Lilly and Company, Indianapolis, IN, USA; 5Centro Paulista de Investigação Clinica, São Paulo, Brazil, 6Presenting on behalf of the authors

Introduction

Baricitinib (BARI) is a reversible oral JAK inhibitor with selectivity for JAK1/JAK2 for active Rheumatoid Arthritis.

Aims/Background

Efficacy and safety were evaluated in pts from RA-BEGIN who switched from methotrexate (MTX) or the combination of BARI+MTX to BARI upon entering LTE study (RA-BEYOND).

Method

In RA-BEGIN, 588 pts were randomised to MTX, BARI monotherapy, or BARI+MTX. At wk 52, pts could enter the LTE; all pts received BARI 4 mg monotherapy. MTX could be added by investigator decision. 451 pts enrolled in LTE: 423 not rescued in RA-BEGIN. This post-hoc analysis evaluated efficacy of pts who continued BARI monotherapy compared to those in whom MTX was added before wk 24.

Results

200/423 (47%) remained on monotherapy at wk 24, and 223 pts started on MTX before wk 24. Most (193) initiated MTX within 4 wks of LTE start. Pts who had MTX added in the LTE had worse disease control upon entry and during the LTE. Through 24 wks, statistically significant improvement in disease state was observed in the MTX-to-BARI group regardless of whether or not MTX was added back. In the BARI-to-BARI monotherapy group, the addition of MTX led to lowered disease activity, which was statistically significant. No statistically significant changes in disease activity were observed in the pts who were switched from BARI+MTX to BARI monotherapy regardless of additional MTX. Exposure-adjusted incidence rates for total treatment-emergent adverse events were lowest in the MTX-to-BARI group. Clinically significant differences in SIE, SAEs, or AEs leading to drug discontinuation were not seen in any of the arms.

Conclusions

Switching from MTX to BARI, maintaining BARI monotherapy was associated with improvements in disease control during the initial 24 wks post-switch. Disease control did not significantly change after MTX withdrawal. Discontinuation of MTX in pts treated with combination during the index study was associated with maintenance of response. Pts who entered the LTE with suboptimal disease control after treatment with BARI monotherapy or who discontinued combination therapy may benefit from the addition of MTX. There were no differences in safety measures including serious events or led to drug discontinuation.