Minimal Disease Activity Provides Valid Assessment of Adalimumab-Treated Psoriatic Arthritis

Minimal disease activity (MDA) provides a stable and valid assessment of disease activity in patients with psoriatic arthritis (PsA) who are initiating treatment with adalimumab, supporting the use of MDA to help guide treatment decisions among patients during routine clinical care. Results of the multicenter, noninterventional, observational trial (ClinicalTrials.gov identifier: NCT01111240) were published in Rheumatology.

Patients with PsA included in the study had initiated adalimumab therapy during routine clinical care and had continued the treatment for at least 6 months. Adult patients aged 18 years or older were enrolled between August 2005 and January 2013. The investigators sought to explore the effectiveness and safety of adalimumab among the treated patients. Eligible patients had active disease (Disease Activity Score in 28 joints [DAS28], ≥1 swollen or tender joints) and complete data for MDA criteria a 6 months. Achievement of MDA and American College of Rheumatology (ACR) responses were examined over the course of 24 months of treatment.

Among 1684 patients who were included in the analyses, most had long-standing disease. MDA was achieved by 35.5% of patients at 6 months. This percentage rose to 45.5% in those who continued to receive adalimumab at 24 months. MDA status remained stable over time.

Overall, more than 75% of patients with MDA at 6 months reported MDA at subsequent visits. Pain was the most difficult of the MDA criteria to achieve, and enthesitis was the least difficult. Higher functional status and lower number of swollen joints at baseline were predictive of attainment of MDA at 6 months. Approximately half (51.5%) of those with a 20% improvement in ACR response criteria at 6 months achieved MDA.

The investigators concluded that the findings of this study support the use of MDA to help guide physicians’ treatment decisions during routine clinical care of patients with PsA. It should be noted that because some patients do take longer than 6 months to achieve MDA while undergoing adalimumab treatment, it may be considered appropriate to continue treatment beyond 6 months before considering a switch in agent.

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Reference

Behrens F, Koehm M, Schwaneck EC, et al. Minimal disease activity is a stable measure of therapeutic response in psoriatic arthritis patients receiving treatment with adalimumab [published online July 13, 2018]. Rheumatology (Oxford). doi: 10.1093/rheumatology/key203