POS1030 EFFICACY OF UPADACITINIB IN PATIENTS WITH PSORIATIC ARTHRITIS STRATIFIED BY BASELINE SKIN SEVERITY: A SUBGROUP ANALYSIS OF TWO PHASE III TRIALS

Abstract

Background:In the SELECT-PsA 1 and 2 clinical trials, upadacitinib (UPA) demonstrated efficacy and safety in patients (pts) with active psoriatic arthritis (PsA).1,2 PsA is associated with varying degrees of psoriatic symptoms; however, the impact of skin severity on treatment outcomes is not well understood.Objectives:This post-hoc analysis assessed the effects of baseline skin severity on UPA efficacy.Methods:SELECT-PsA 1 and SELECT-PsA 2 enrolled pts with PsA and prior inadequate response (IR) or intolerance to ≥1 non-biologic disease-modifying antirheumatic drug (DMARD)1 or ≥1 biologic DMARD2, respectively. In both trials, pts received once daily UPA 15 mg or UPA 30 mg or placebo (switched at Wk 24 to either UPA 15 mg or 30 mg); SELECT-PsA 1 also included the active comparator adalimumab (ADA). Only continuous UPA 15 mg and ADA are presented here. In this analysis, pts were divided into subgroups based on the extent of psoriasis at baseline (body surface area [BSA] of ≥3%-<10% or BSA ≥10%); efficacy endpoints were analyzed at Wk 56. Results for binary endpoints are based on non-responder imputation; continuous endpoints are based on mixed model repeated measures analysis with as-observed data.Results:In the UPA 15 mg and ADA groups, respectively, 32% (138/429) and 31% (132/429) of pts had a BSA ≥3-<10% at baseline in SELECT-PsA 1; 18% (76/429) in each treatment group had a BSA ≥10%. In SELECT-PsA 2, 38% (80/211) had a BSA ≥3-<10% and 24% (50/211) had a BSA ≥10% at baseline in the UPA 15 mg group. Across pt populations (non-biologic DMARD-IR and biologic DMARD-IR), generally consistent results were observed between patients in both skin severity subgroups (Figure 1). In non-biologic DMARD-IR pts, a numerically greater proportion of UPA 15 mg pts with lower skin involvement compared with higher skin involvement achieved PASI100 and PASI≤1, two more stringent skin endpoints. The achievement of MDA was generally consistent across skin severity subgroups; when pts were required to achieve the skin component of MDA, results were numerically better in the ≥3-<10% skin severity group (Table 1). In non-biologic DMARD-IR pts, results were similar between UPA 15 mg and ADA.Conclusion:UPA is a viable treatment option for pts with active PsA regardless of the extent of psoriasis at baseline. Although these results are of interest and hypothesis-generating, they should be interpreted with caution due to low sample size.