Comparison of disease activity index for psoriatic arthritis (DAPSA) and minimal disease activity (MDA) targets for patients with psoriatic arthritis: A post hoc analysis of data from phase 3 tofacitinib studies.

OBJECTIVE

To compare achievement of Disease Activity Index in Psoriatic Arthritis (DAPSA) remission (REM)/low disease activity (LDA) with very low disease activity (VLDA)/minimal disease activity (MDA) targets in tofacitinib-treated patients with psoriatic arthritis (PsA).

METHODS

In this post hoc analysis, data were pooled from two phase 3 studies (6 months' [NCT01882439] and 12 months' [NCT01877668] duration) of patients with PsA receiving tofacitinib 5 or 10 mg twice daily. Cut-offs for DAPSA targets: ≤4 for clinical REM and >4-≤14 for LDA. VLDA and MDA were defined as meeting 7 or ≥5, respectively, of 7 criteria. An ordered logistic regression model was performed to evaluate associations between baseline characteristics and achievement of DAPSA targets as well as VLDA/MDA at month 3. Agreement between achieving DAPSA and VLDA/MDA targets at months 1-6 was assessed via kappa tests. Change from baseline in Health Assessment Questionnaire-Disability Index (HAQ-DI) and Short Form-36 Health Survey (SF-36) Physical Component Summary (PCS) scores (month 6), modified Total Sharp Score (mTSS) and proportion of radiographic non-progressors (mTSS ≤0.5) at month 12 (NCT01877668 only) were compared across DAPSA and VLDA/MDA targets.

RESULTS

Increased disease activity at baseline was associated with reduced likelihood of achieving DAPSA-REM/DAPSA-LDA or VLDA/MDA at month 3. There was moderate agreement (kappa values 0.41-0.60) between DAPSA-REM and VLDA, and DAPSA-LDA and MDA, from months 1 to 6, although over half of patients achieving DAPSA-REM and over two thirds of patients achieving DAPSA-LDA, respectively, were not captured by VLDA and MDA. Achieving DAPSA-REM/DAPSA-LDA or VLDA/MDA was associated with improved HAQ-DI and SF-36 PCS scores at month 6, and slightly reduced radiographic progression at month 12.

CONCLUSION

This analysis of data from tofacitinib-treated patients with PsA demonstrated moderate agreement between the DAPSA and VLDA/MDA composite instruments. In agreement with previous studies, VLDA and MDA may be more difficult to achieve than DAPSA-REM and DAPSA-LDA, respectively. However, the clinical and prognostic relevance of this finding should be determined. These data support DAPSA and VLDA/MDA as useful tools for evaluating disease activity and treatment response in PsA.

CLINICALTRIALS: GOV: NCT01882439; NCT01877668.