Clinical and economic impact of the use of etanercept 25 mg once weekly in rheumatoid arthritis, psoriatic arthropathy and ankylosing spondylitis patients.

Objective: To determine the clinical and economic impact of etanercept 25 mg/week (ETN25) on rheumatoid arthritis (RA), psoriatic arthropathy (PA) and ankylosing spondylitis (AS) patients in sustained clinical remission.

Methods: Observational, retrospective cohort of patients treated with etanercept 50 mg/week (ETN50) who achieved and maintained clinical remission (Disease Activity Score 28 < 2.6 or BASDAI < 2) over a period of 1 year and had slow worsening of structural changes were enrolled in an off-label program (January 2006 to June 2013) to switch from ETN50 to ETN25. Economic impact was assessed using Enbrel® official prices for Spain.

Results: From 1 January 2006 to 1 June 2013, 98 RA, 40 PA and 47 AS patients were treated with ETN50; 39 (24%) patients (20 women; age = 53 ± 7 years; 24 RA, 7 PA, 8 AS) received ETN25 for at least 0.5 years (2.6 ± 2.0 years; range = 0.5 - 7.3 years). As of 1 June 2013, 29 (74%) patients continued on ETN25. RA patients: 17 patients continued on ETN25, 5 patients discontinued use due to reactivation of RA (4 switched back to ETN50 and 1 switched to adalimumab; all regained clinical remission) and 2 patients discontinued use due to adverse reactions. PA patients: four patients continued on ETN25, two patients discontinued use due to reactivation of PA (switched back to ETN50, regaining clinical remission) and one patient discontinued use due to adverse reaction. All AS patients continued on ETN25. The total savings associated with ETN25 over the 7-year observation period were €622,073, resulting in the ability to treat 52 additional patients with ETN50 for one year without increasing total ETN costs.

Conclusion: ETN25 produces cost savings while maintaining clinical response in a high proportion of patients after at least one year under clinical remission with ETN50. At a time when the cost of therapy is an unavoidable component of healthcare treatment decisions, ETN25 could be a cost-effective option for selective RA, PA and AS patients.