People with psoriatic arthritis (PsA) had better patient-reported outcomes with abatacept treatment compared with placebo, according to a study recently published in Arthritis Research & Therapy. Improvements were observed among subgroups with higher baseline C-reactive protein (CRP) and tumor necrosis factor inhibitor (TNFi) naivety.
This study included 424 randomly assigned participants with PsA, 213 of whom were assigned to 24 weeks of weekly subcutaneous abatacept 125 mg, and 211 of whom were assigned to placebo. At 24 weeks, all participants were given open-label abatacept. Early escape to open-label abatacept at 16 weeks was available to participants who had not improved by at least 20% in counts of tender or swollen joints. Assessments of adjusted mean changes to 16 and 24 weeks (all participants and non-early escape, respectively) were performed. Subgroup analyses included previous exposure to TNFi and CRP levels relative to upper limits of normal. Analysis was performed on the number of patient-reported improvements meeting or exceeding the minimal clinically important differences and normative values in the corresponding indices.
Among the study population, 35.7% of the abatacept group and 42.2% of the placebo group were eligible for early escape. Patient-reported outcomes were better among the treatment group vs placebo (P >.05), with more week 16–reported improvements above the minimal clinically important difference and normative value levels. Participants whose CRP level was above the upper limit of normal at baseline showed greater improvements at 16 weeks, while those who were TNFi-naive showed greater improvements compared with non-naive participants in Short Form-36 and Functional Assessment of Chronic Illness Therapy-Fatigue indices.
Limitations to this study included post-hoc comparisons of certain scores and a large number of early-escape participants, which lowered patient numbers and limited P-values to non-statistical significance. Some patient-reported improvements also diminished over time, resulting in later-treatment effects of abatacept that may not have been accounted for.
The study researchers conclude that “abatacept treatment improved [patient-reported outcomes] at week 16 in patients with active PsA, with evidence of some effects sustained at week 24. Furthermore, [patient-reported outcome] improvements were greater in TNFi-naive patients and those with elevated CRP. These results demonstrate that clinical improvements in PsA signs and symptoms previously reported with abatacept treatment also result in clinically meaningful improvements in [patient-reported outcomes].”
This study received funding from Bristol-Myers Squibb pharmaceutical company, and several authors report financial associations with pharmaceutical companies. For a full list of author disclosures, please see original source.
Strand V, Alemao E, Lehman T, et al. Improved patient-reported outcomes in patients with psoriatic arthritis treated with abatacept: results from a phase 3 trial. Arthritis Res Ther. 2018;20:269.