DAPSA, MDA Are Useful Tools for Evaluating Disease Activity, Treatment Response in PsA

Data from patients with psoriatic arthritis (PsA) receiving treatment with tofacitinib demonstrates moderate agreement between the Disease Activity Index in Psoriatic Arthritis (DAPSA) and the very low disease activity/minimal disease activity (VLDA/ MDA) composite instruments, according to the results of a post hoc analysis published in Seminars in Arthritis & Rheumatism.

The researchers sought to compare the achievement of DAPSA remission/LDA with VLDA/MDA targets among patients with PsA receiving treatment with the Janus kinase inhibitor (JAK) tofacitinib.

Data were pooled from 2 phase 3 placebo-controlled studies, ie, the 6-month OPAL Beyond study (ClinicalTrials.gov Identifier: NCT01882439) and the 12-month OPAL Broaden study (ClinicalTrials.gov Identifier: NCT01877668).

In the 2 trials, patients with PsA received treatment with tofacitinib 5 mg or 10 mg twice daily. Cutoffs for DAPSA targets were 4 or lesser for clinical remission and greater than 4 to 14 or lesser for LDA. In addition, VLDA and MDA were defined as fulfilling 7 or at least 5, respectively, of the 7 criteria.

Associations between baseline characteristics and attainment of DAPSA targets, as well as VLDA/MDA targets, at month 3 were assessed using an ordered logistic regression model. Kappa tests were used to evaluate agreement between achievement of DAPSA and VLDA/MDA targets at months 1 through 6.

Further, change from baseline in Health Assessment Questionnaire-Disability Index (HAQ-DI) and Short Form-36 Health Survey (SF-36) Physical Component Summary (PCS) scores at month 6, as well as modified Total Sharp Score (mTSS) and percentage of radiographic nonprogressors (mTSS ≤0.5) at month 12, were compared across DAPSA and VLDA/MDA targets.

Results of the study showed that increased disease activity at baseline was associated with a reduced likelihood of attaining DAPSA remission/DAPSA-LDA or VLDA/MDA at
3 months. Moderate agreement (kappa values, 0.41-0.60) was demonstrated from months 1 through 6 between DAPSA remission and VLDA, as well as between DAPSA-LDA and MDA; however, data from more than 50% of participants who achieved DAPSA remission and more than 66% of those who attained DAPSA-LDA, respectively, were not captured by VLDA and MDA.

In addition, attainment of DAPSA remission/DAPSA-LDA or VLDA/MDA was linked to improved HAQ-DI and SF-36 scores at 6 months, as well as slightly reduced radiographic progression at 12 months.

OPAL Beyond and OPAL Broaden were not designed to or statistically powered to compare VLDA/MDA responses with DAPSA states in patients with PsA receiving treatment with tofacitinib. In addition, data were pooled from only 2 clinical trials that enrolled a small number of patients.

The study authors concluded, “This post hoc analysis of data from tofacitinib-treated patients with PsA demonstrates the closeness of patients achieving both DAPSA and MDA targets, with those achieving DAPSA but not MDA targets, mainly in musculoskeletal domains…These data support that DAPSA and VLDA/MDA composite instruments are useful measurement tools for evaluating disease activity and treatment response in PsA.”

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.