Background/Purpose: Apremilast (APR) is an oral phosphodiesterase 4 inhibitor that helps regulate the aberrant immune response that causes the joint symptoms, systemic inflammation, and skin disease associated with psoriatic arthritis (PsA). The Work Limitations Questionnaire (WLQ) measures the degree to which employed individuals are experiencing limitations on the job due to their health problems, as well as health-related productivity loss. The PALACE 1 study compared the efficacy and safety of APR with placebo in patients with active PsA despite prior or concurrent conventional disease-modifying antirheumatic drugs (DMARDs) and/or prior biologics. The objective of the current analysis was to assess the effect of APR on work productivity and work limitations of employed patients in the PALACE 1 study.

Methods: Patients were randomized (1:1:1) to receive placebo, APR 20 mg BID (APR20), or APR 30 mg BID (APR30) stratified by baseline DMARD use (yes/no). Treatment efficacy was assessed at Week 16 based on the intent-to-treat population. Employed patients completed the WLQ, a 25-item questionnaire that assesses the impact of chronic health conditions on work performance and productivity, at baseline and Week 16. Work limitations were categorized into 4 domains, which were then used to calculate the WLQ index: physical demands (PDS), mental demands (MDS), time management demands (TMS), output demands (ODS). Improvement in the WLQ index, and its 4 domains, is represented by a negative change from baseline. Improvement in work productivity is represented by a positive improvement in percentage of productivity loss.

Results: 504 patients were randomized (mean age: 50.4 years; 49.4%: male). Of these 261 who were both employed and completed at least 1 component of the WLQ were analyzed. At Week 16, APR20 and APR30, vs. placebo, were associated with a greater mean change from baseline in PDS (-5.58 and -6.24 vs. -2.14), MDS (-2.22 and -5.18 vs. 1.15), TMS (-4.03 and -8.76 vs. -4.25), and ODS (-5.92 and -10.3 vs. -1.34), resulting in a greater mean improvement in the WLQ index (-0.01 and -0.03 vs. 0.00), which corresponds to a higher median percent improvement of productivity loss (18.9% and 24.7% vs. -3.7%). Higher productivity improvements were also observed among APR20 and APR30 ACR20 responders at Week 16—PDS (-11.8 and -7.61), MDS
(-8.56 and -11.0), TMS (-7.88 and -15.8), and ODS (-10.6 and -20.1), respectively—resulting in a higher mean improvement in the WLQ index (-0.03 and -0.05, respectively), which corresponds to a higher median percent improvement in work productivity (57.9% and 46.8%), respectively.

Conclusion: APR20 and APR30 increased work productivity and improved work limitations among patients active PsA who were not adequately controlled with prior or concurrent conventional DMARDs and/or prior biologics.