Enbrel® for Psoriatic Arthritis

Enbrel is indicated for the treatment of active and progressive PsA in adults when the response to previous DMARD therapy has been inadequate. Enbrel has been shown to improve physical function in patients with PsA, and to reduce the rate of progression of peripheral joint damage as measured by X-ray in patients with polyarticular symmetrical subtypes of the disease.¹ 

• Hypersensitivity to the active substance or to any of the excipients¹
• Sepsis or risk of sepsis¹
• Treatment with Enbrel should not be initiated in patients with active infections, including chronic or localised infections¹

The recommended dose of Enbrel in adults is 25 mg administered twice weekly, or 50 mg administered once weekly.¹

Data suggest that a clinical response is usually achieved within 12 weeks of treatment. Continued therapy should be carefully reconsidered in a patient not responding within this time period.¹

The efficacy of Enbrel was assessed in a randomised, double-blind, placebo-controlled study in 205 patients aged 18–70 years with active PsA. Patients also had plaque psoriasis with a qualifying target lesion ≥ 2 cm in diameter. Patients had previously been treated with NSAIDs (86%), DMARDs (80%), and corticosteroids (24%). Patients currently on MTX therapy (stable for ≥ 2 months) could continue at a stable dose of ≤ 25 mg/week MTX. Doses of 25 mg of Enbrel or placebo were administered SC twice a week for 6 months.²

Clinical responses were expressed as percentages of patients achieving the ACR 20, 50, and 70 response and improvement in PsARC.²

Adapted from Mease, et al. 2004.
*25 mg of Enbrel administered SC twice weekly
†p<0.001, Enbrel vs. placebo
‡p<0.01, Enbrel vs. placebo​​​​​​​

Among patients with PsA who received Enbrel, the clinical responses were apparent at the time of the first visit (4 weeks) and were maintained through 6 months of therapy. Enbrel was significantly better than placebo in all measures of disease activity (p < 0.001), and responses were similar with and without concomitant MTX therapy. Quality of life in PsA patients was assessed at every timepoint using the disability index of the HAQ. The disability index score was significantly improved at all timepoints in PsA patients treated with Enbrel, relative to placebo (p < 0.001).^{2​​​​​​​}

The percentage of patients without disease progression (TSS change ≤ 0.5) at 12 months was higher in the Enbrel group compared with the placebo group (73% vs. 47%, respectively, p ≤ 0.001). The effect of Enbrel on radiographic progression was maintained in patients who continued on treatment during the second year. The slowing of peripheral joint damage was observed in patients with polyarticular symmetrical joint involvement.²

Enbrel treatment resulted in improvement in physical function during the double-blind period, and this benefit was maintained during the longer-term exposure of up to 2 years.²

The most commonly reported adverse reactions are injection site reactions (such as pain, swelling, itching, reddening and bleeding at the puncture site), infections (such as upper respiratory infections, bronchitis, bladder infections and skin infections), allergic reactions, development of autoantibodies, itching, and fever.¹

Serious adverse reactions have also been reported for Enbrel. TNF-antagonists, such as Enbrel, affect the immune system and their use may affect the body's defenses against infection and cancer. Serious infections affect fewer than 1 in 100 patients treated with Enbrel. Reports have included fatal and life-threatening infections and sepsis. Various malignancies have also been reported with use of Enbrel, including cancers of the breast, lung, skin and lymph glands (lymphoma).¹

Serious haematological, neurological and autoimmune reactions have also been reported. These include rare reports of pancytopenia and very rare reports of aplastic anaemia. Central and peripheral demyelinating events have been seen rarely and very rarely, respectively, with Enbrel use. There have been rare reports of lupus, lupus-related conditions, and vasculitis.¹

Before prescribing Enbrel refer to the full Summary of Product Characteristics.

ACR=American College of Rheumatology; DMARD=disease-modifying antirheumatic drug; HAQ=Health Assessment Questionnaire; JIA=juvenile idiopathic arthritis; MTX=methotrexate; nr-AxSpA=non-radiographic axial spondyloarthritis; NSAID=non-steroidal anti-inflammatory drug; PsA=psoriatic arthritis; PsARC=psoriatic arthritis response criteria; SC=subcutaneous; TNF=tumour necrosis factor; TSS=total sharp score.