Drug survival of fumaric acid esters for psoriasis: a retrospective study

Fumaric acid esters (FAEs) have been used for over 30 years in the management of psoriasis.

To determine drug survival of FAEs in patients with psoriasis, treatment-limiting adverse drug events and the range of effective drug doses.

A retrospective, single-centre study assessing all patients commenced on FAEs between October 2003 and July 2012. Demographic data, length of treatment, reasons for discontinuation of FAEs, side-effects and range of doses were recorded.

Two hundred and forty-nine patients [160 (64%) male] were included. The mean age at which FAEs were commenced was 44·5 years (range 17-82 years). The mean length of treatment was 28 months (range 1 week to 106 months). In patients who were commenced on FAEs ≥ 4 years before inclusion in this study, the 4-year drug survival was 60% (64/107). FAEs were discontinued in 146/249 patients (59%); this was due to lack of efficacy in 59/146 (40%) and gastrointestinal upset in 39/146 (27%). A very low dose of FAEs (< 240 mg daily) was successful in maintaining control of psoriasis in 26 (10%) patients. The mean treatment duration of these patients was 64 months (range 32-106 months).

Fumaric acid esters have a 4-year drug survival rate of 60%, which compares favourably with reported 4-year survival rates of 40% for etanercept and adalimumab and 70% for infliximab. Longer drug survival is more likely in the significant subgroup of patients in whom a very low dose of FAEs is sufficient to control disease. The reasons for this are unclear.