Retrospective study of the management of Psoriatic Arthritis with tumour necrosis factor inhibitors in the UK: Capture Study

Background

Several TNF inhibitors (TNFis) are available to treat PsA in the UK, with Psoriatic Arthritis Response Criteria (PsARC) recommended for assessment of response. Patients may remain on the first TNFi for prolonged periods, and while this indicates sustained clinical effectiveness, it may also reflect a lack of alternative therapeutic options. The objective of this study was to characterize PsA management with TNFis during normal clinical care in the UK NHS.

Methods

CAPTURE was a retrospective observational study in 11 centres that included 141 consenting NHS patients with a documented diagnosis of PsA [according to Classification of Psoriatic Arthritis (CASPAR) criteria] who were initiated on their first TNFi ≥3 years previously and ≥18 years of age. Data were collected from medical records, including patient and clinical characteristics at initiation of the first TNFi (baseline), TNFi prescribed and PsARC variables. The median duration of the study period (initiation of the first TNFi to the date of data collection) was 4.5 years (range 3.4–5.5). Where data were not available for all patients, the denominator is shown.

Results

Seventy-one (50.4%) patients were female. The median age at PsA symptom onset was 38.1 years (range 11.9–67.3; n = 130), at PsA diagnosis 40.0 years (15.0–67.4; n = 138) and at initiation of first TNFi 50.0 years (23.2–76.6). At baseline, 29.8% (42/141) of patients had PsA-related nail involvement, 19.1% (27/141) had enthesitis and 18.4% (26/141) had dactylitis. During the study period, 68.1% (96/141) of patients received one TNFi only, 19.9% (28/141) received two and 12.1% (17/141) received three or more. Adalimumab [57.4% (81/141)] and etanercept [40.4% (57/141)] were the most frequently prescribed first-use TNFis. Forty-one of 141 patients had data available to calculate PsARC response 12 weeks post-initiation of the first TNFi: 73.2% (30/41) had a PsARC-defined response, of whom 20 did not discontinue the first TNFi. Eleven of 41 (26.8%) patients did not have a PsARC-defined response, but of these only 6 switched to a second TNFi. Three years post-initiation of the first TNFi, 64.5% (91/141) of patients remained on the first TNFi, 24.1% (34/141) were receiving an alternative TNFi and 11.3% (16/141) had permanently discontinued TNFi therapy. The most common reasons for discontinuation of the first TNFi at any time were failure to respond [32.3% (20/62)], loss of response [12.9% (8/62)], intolerance [17.1% (11/62)] and infections [11.3% (7/62)].

Conclusions

In this study of a representative patient group treated with TNFis and where data were available approximately three-quarters of patients achieved a PsARC response after 12 weeks, comparable with published trial data. While missing data are a limitation of any retrospective study, the extent of PsARC data not documented in the patients’ medical notes was unexpected. Missing data may reflect that the PsARC response is not always appropriately documented and/or routinely assessed. This is despite clear guidance from the National Institute for Health and Care Excellence, and may indicate the need to establish specialized PsA clinics in order to optimize patient management.