Psoriatic arthritis (PsA) is a heterogeneous disease involving the musculoskeletal structures, the skin and nails.1 2 Traditional disease-modifying antirheumatic drugs and tumour necrosis factor β (TNFβ) antagonists are effective on cutaneous and articular manifestations of psoriatic disease.3 4

Most patients with PsA are successfully treated with TNFβ antagonists. However, a subset of patients with PsA are not responsive to these treatments or do not maintain a clinical response to the cutaneous manifestations despite the remission of arthritis.5

The primary objective of this study was to evaluate the safety and efficacy of adding ciclosporin A (CsA) to etanercept in patients with PsA demonstrating an unsatisfactory control of cutaneous manifestations.

A 24-week pilot open-label trial with follow-up visits scheduled at 8, 16 and 24 weeks was carried out in consecutive patients with PsA receiving etanercept treatment (50 mg/week, for at least 6 months) with insufficient response to skin disease (Psoriasis Area Severity Index (PASI)6 ≥10) while in remission of arthritis (swollen joint count ≤1, tender joint count ≤2, dactylitic digits ≤1, Maastricht Ankylosing Spondylitis Enthesitis Score (MASES)7 ≤2). In the enrolled patients CsA was added at a dose of 3.0 mg/kg/day. Local ethics committee approval and patient written informed consent were obtained before study procedures were undertaken.

The primary efficacy end point was to achieve a 75% or greater improvement from baseline in the PASI (PASI 75) at week 24. Other end points are shown in table 1. Safety was evaluated by carefully questioning and examination of the patients for adverse events and by performing all standard laboratory investigations at each follow-up visit.

Among the 103 patients with PsA, classified according to the CASPAR criteria,8 treated with etanercept who were screened during the 12-month recruitment period, 11 (10.7%) had an unsatisfactory control of cutaneous manifestations and were enrolled for combination treatment with CsA. Among the 11 enrolled patients (five women, six men; median age 54 years, range 35–71; median disease duration of PsA 10 years, range 1–34; median disease duration of psoriasis 21 years, range 1–54), two had concomitant hepatitis C virus (HCV) infection and one had hypertension well controlled by an antihypertensive agent.

The PASI 75 was achieved in nine patients at week 24; in six and eight patients at week 8 and 16, respectively. All other outcome measures confirmed the efficacy of the combination therapy with etanercept and CsA (table 1). No patient withdrew owing to lack of efficacy. Etanercept treatment remained unchanged during the study period. CsA was discontinued in one patient owing to increased serum creatinine after 16 weeks. In one patient the dose of CsA was reduced by 2.5 mg/kg/day owing to the deterioration of a pre-existent hypertension without any negative effect on the control of cutaneous manifestations. The two patients with HCV hepatitis had no worsening of their liver function studies.

In conclusion our study suggests that the addition of CsA to etanercept seems to be a safe and effective treatment for patients with PsA with uncontrolled cutaneous disease. In these patients, this therapeutic approach could be an alternative option to the switching of TNFβ antagonists.