Background/Purpose: Tofacitinib is an oral Janus kinase inhibitor for the treatment of RA, in combination with MTX or other non‑biologic (nb)DMARDs, or as monotherapy. Two pooled open-label long-term extension studies previously showed that patients (pts) discontinuing concomitant MTX or glucocorticoids (GC) could maintain favorable treatment response.¹ This analysis of real world data assessed characteristics of pts who discontinued MTX after tofacitinib treatment.

Methods: This retrospective cohort study included pts aged ≥18 years in the Truven MarketScan™ US Commercial and Medicare Supplemental claims database with ≥2 tofacitinib claims (first = index) with <60-day gap between 1/1/2014–1/31/2017, ≥2 oral MTX claims (one ≤90 days post-index) with <60-day gap, and an RA diagnosis on or within 12 months pre‑index. Pts were continuously enrolled for ≥12 months pre-/post-index with no prior claim for tofacitinib 12 months pre‑index. Pts were assigned to mutually exclusive cohorts for analysis by 12‑month post-index MTX persistence: “persistent” (MTX‑P; ≤60‑day gap), “discontinued” (MTX-D; >60-day gap) and “interrupted” (MTX‑I; >60-day gap with ≥1 subsequent MTX claim 12 months post-index). Outcomes at 12 months post‑index were tofacitinib persistence (<60-day gap), adherence (proportion of days covered), effectiveness (composite measure; defined in Table)^2,3 and RA-related costs. Two sample tests (t-test, chi-squared) were applied separately to MTX-P vs combined MTX-D and MTX-I, and pair-wise among the 3 cohorts, with no adjustment for multiple comparisons or imbalances in baseline covariates.

Results: 479 pts met inclusion criteria (MTX-P: 337 [70%]; MTX-D: 94 [20%]; MTX-I: 48 [10%] in the 12-month post-index period). Demographic and baseline clinical characteristics were similar among cohorts, aside from differences in the proportion of males and all-cause out-of-pocket costs (p<0.05; Table).

Tofacitinib persistence, adherence and effectiveness over 12 months were similar between MTX-D and MTX-P. RA-related total and pharmacy costs were lower in MTX-D vs MTX-P (p<0.001 and p<0.05, respectively).

Conclusion: This analysis of US-based claims data showed that pts who initiate tofacitinib with oral MTX can discontinue MTX with similar persistence, adherence and effectiveness, and lower RA-related total/pharmacy costs 12‑months post-index vs MTX‑persistent pts. Further analysis with a larger sample size is needed to confirm the robustness of these findings; further investigation is also needed regarding the MTX-I group as interpretation of this group is limited by the small sample size. Findings are limited by the use of claims data which may reflect MTX discontinuation/interruption related to pt choice without physician knowledge.

References:

1.     Fleischmann R et al. Rheumatol Ther 2018; 5: 203-14.

2.     Curtis JR et al. Arthritis Res Ther 2011; 13: R155.

3.     Oladapo A et al. J Manag Care Spec Pharm 2014; 20: 657-67.