POS0086 ANALYSIS OF DISEASE ACTIVITY MEASURES IN THE CONTEXT OF A METHOTREXATE WITHDRAWAL STUDY AMONG PATIENTS WITH RHEUMATOID ARTHRITIS TREATED WITH TOFACITINIB 11 MG ONCE DAILY + METHOTREXATE: POST HOC ANALYSIS OF DATA FROM ORAL SHIFT

Abstract

Background:The Phase 3b/4 study ORAL Shift demonstrated sustained efficacy and safety of tofacitinib modified-release (MR) 11 mg once daily (QD) following methotrexate (MTX) withdrawal that was non-inferior to continued tofacitinib + MTX use (per DAS28-4[ESR]), in patients (pts) with rheumatoid arthritis (RA) who achieved CDAI-defined low disease activity (LDA) with tofacitinib + MTX at Week (W)24.1Objectives:To assess the performance of alternative disease activity measures at W24 (randomisation) and W48 (study endpoint) in ORAL Shift.Methods:ORAL Shift (NCT02831855) enrolled pts aged ≥18 years with moderate to severe RA and an inadequate response to MTX. Pts received open-label tofacitinib MR 11 mg QD + MTX for 24 weeks. Achievement of CDAI LDA (≤10) at W24 was set as the criteria for entry to the 24-week double-blind MTX withdrawal phase, with pts randomised 1:1 to receive tofacitinib MR 11 mg QD + placebo (PBO) (ie blinded MTX withdrawal) or continue tofacitinib + MTX. In this post hoc analysis, efficacy analyses were performed in 8 subgroups defined by achievement of various disease activity criteria at W24: DAS28-4(ESR) remission (<2.6) or LDA (≤3.2); DAS28-4(CRP) <2.6 or ≤3.2; RAPID3 remission (≤3) or LDA (≤6); CDAI remission (≤2.8); and SDAI remission (≤3.3). For each subgroup, the proportion of pts who achieved the corresponding disease activity criterion at W48 was calculated, with a 95% confidence interval (CI) estimated using the normal approximation to the binomial distribution. The change (Δ) from W24 to W48 in least squares (LS) mean DAS28-4(ESR) and DAS28-4(CRP) was also calculated in each subgroup, with a 95% CI for the difference between treatment groups estimated using a mixed model with repeated measures. Nominal p values were calculated and are presented with no formal statistical hypothesis testing formulated.Results:Overall, 694 pts entered the open-label phase of ORAL Shift, and 530 were randomised and received treatment in the double-blind phase; 264 and 266 pts received tofacitinib + PBO and tofacitinib + MTX, respectively (Figure 1a). Considering those pts who were randomised and treated, the proportion of pts achieving each disease activity criterion at W24 varied, but was similar between treatments within each subgroup (Figure 1a). Among pts who met each disease activity criterion at W24, generally the majority of pts in both treatment groups also met the same criterion at W48 (Figure 1b). Numerically more pts receiving tofacitinib + MTX vs tofacitinib + PBO continued to meet the corresponding criterion at W48. Regardless of the disease activity criterion met at W24, differences between treatment groups in LS mean ΔDAS28-4(ESR) (Figure 1c) and ΔDAS28-4(CRP) (data not shown) from W24 to W48 favoured tofacitinib + MTX vs tofacitinib + PBO.Conclusion:This post hoc analysis of data from pts randomised and treated in ORAL Shift demonstrated that, regardless of the disease activity state criterion met at W24, generally a majority of pts receiving tofacitinib maintained achievement of the corresponding disease activity criterion at W48, with or without continued MTX. Differences between treatment groups in LS mean ΔDAS28-4(ESR) from W24 to W48, as defined by achievement of LDA or remission with a variety of disease activity measures, were less than a change of 1.2, which is considered to be the threshold for a minimal clinically important improvement.2