gms | German Medical Science

Background: In the Phase III ASTRAEA study (NCT01860976), abatacept significantly increased ACR20 responses, alleviating musculoskeletal symptoms in patients with active psoriatic arthritis (PsA) [1]. As PsA impacts HRQoL, assessing treatment effect using patient-reported outcomes (PROs) is important. Here we explore the effect of abatacept on PROs in ASTRAEA.

Methods: Patients were randomized (1:1) to SC abatacept 125 mg weekly or placebo for 24 weeks (W). At W16, patients without ≥20% improvement in joint counts escaped to open-label abatacept. Adjusted mean changes from baseline to W16 (all patients) and W24 (non-escape responder analysis) in Short Form-36 (SF-36; physical and mental component summary [PCS, MCS] and individual domains using spydergrams), HAQ-DI, Dermatology QoL Index (DLQI) and Functional Assessment of Chronic Illness Therapy-Fatigue scale (FACIT-F) scores were evaluated in total population (prespecified intention-to-treat analysis) and subgroups (post hoc) stratified by baseline CRP level and prior TNF inhibitor (TNFi) use. Proportions of patients reporting improvements from baseline ≥minimal clinically important difference (MCID) in SF-36 summary (≥2.5) and domains (≥5.0), FACIT-F (≥40) and HAQ-DI (<–0.22), and ≥normative values in SF-36 summary (≥50) and individual domains, FACIT-F (<40) and HAQ-DI (<0.5) at W16 were analysed in the total population.

Results: In the total population, numerical improvements in most PROs were observed for abatacept (n=213) versus placebo (n=211) at both time points (significant for SF-36 PCS at W16, HAQ-DI at W24 and DLQI at both time points; Table 1 [Tab. 1]). At W16 before escape, improvements in all SF-36 domains were numerically greater with abatacept (significant for physical function, bodily pain and vitality). A higher proportion of patients receiving abatacept versus placebo reported improvements ≥MCID in SF-36 PCS, SF-36 MCS, SF-36 domains, FACIT-F, HAQ-DI (Figure 1 [Fig. 1]) and DLQI (not shown) at W16. Proportion of patients with ≥normative values at W16 was higher with abatacept versus placebo for SF-36 PCS, SF-36 MCS, FACIT-F and HAQ-DI. At W24, improvements in most SF-36 domain scores accrued in responders in both groups, with numerical differences favouring abatacept. Improvements were observed in all PROs in the abatacept versus placebo group for the TNFi-naïve and -exposed subpopulations at W16. Improvements in all PROs were reported with abatacept in baseline CRP >upper limit of normal (ULN) versus CRP ≤ULN subpopulation at W16 (Table 1 [Tab. 1]). Subgroup data at W24 were difficult to interpret due to lower number of patients assessed versus W16.[IMG1][IMG2][IMG3]

Conclusion: Abatacept treatment improved many PROs in patients with active PsA, with larger benefits in the CRP >ULN subpopulation. Improvements were seen with abatacept regardless of prior TNFi exposure.