A retrospective observational study of effectiveness of sequential biologic and targeted synthetic DMARDs in psoriatic arthritis in the UK.

Abstract

Evidence evaluating effectiveness of biologic and targeted synthetic DMARDs (b/tsDMARDs) in adults with PsA after exposure to three or more b/tsDMARDs is lacking. We aimed to evaluate response to sequential lines of b/tsDMARDs. In this multicentre retrospective observational study, 22 hospitals submitted data from routine clinic appointments of patients with PsA treated with b/tsDMARDs. Purposive sampling obtained a study population exposed to advanced lines of therapy. Effectiveness outcome measures (Psoriatic Arthritis Response Criteria [PsARC]/tender joint count [TJC]/swollen joint count [SJC]) at baseline and first follow-up (12-16 weeks) for each line were recorded. Odds of achieving PsARC in 2nd/3rd line were compared with 4th+ line. Four hundred and thirty-seven participants (163 male, 274 female) and 1459 treatment courses were included: 430 1st line, 633 2nd/3rd line and 396 4th+ line. The adjusted odds ratio (95% CI) for achieving PsARC in 1st line vs 2nd/3rd line was 1.91 (1.40, 2.60) and 4th+ line vs 2nd/3rd line was 1.13 (0.84, 1.55). There was no significant difference in change from baseline TJC/SJC between 2nd/3rd and 4th+ lines. In this cohort the highest chance of a positive PsARC response was to 1st line b/tsDMARD: twice the chance of response vs 2nd/3rd line. The chance of a positive PsARC response to 4th+ lines of b/tsDMARD was not significantly different from 2nd/3rd lines after adjustment. This indicates that patients in a UK cohort can continue to have a meaningful response to later lines of treatment. This is the first available evidence of response to later lines of b/tsDMARD treatment in PsA.