Background Biological based therapies, such as subcutaneous anti-tumour necrosis factor α, including etanercept or adalimumab, or ustekinumab, an agent which targets interleukin (IL)-12 and IL-13 cytokines, has greatly improved treatment of psoriasis. Medication persistence, defined as ‘the duration of time from initiation to discontinuation of therapy’, is an important element in determining the success of any long term therapy.

Purpose To evaluate the persistence of firstline adalimumab, etanercept and ustekinumab in psoriasis.

Material and methods Observational, retrospective, longitudinal study. All adult psoriasis (Pso) patients treated with etanercept, adalimumab and ustekinumab as a firstline biological treatment were included.

Persistence was calculated as the number of days from the index prescription to the date of the final dispensing or end of the observation period (September 2015). Persistence was also calculated as a dichotomous variable measured at the end of the first, second and third years of therapy (calculated over patients who started treatment 1, 2 or 3 years before the analysis, respectively).

For analysis of persistence, a survival analysis with the Kaplan–Meier estimator was used. Cox regression was used to compare persistence between different drugs, and the hazard ratio was calculated.

Data were collected from medical and drug dispensation records (Farmatools). Data management and statistical analyses were performed using SPSS Statistics v.15.0 (IBM, Armonk, New York, USA).

Results 124 patients were included (38.7% etanercept, 41.9% adalimumab and 19.4% ustekinumab). Mean ± SD age was 52.1 ± 14.5 years. 69.4% were male. Persistence rates at the first, second and third years of treatment were 83.0%, 75.0% and 60.5% for etanercept, 63.3%, 54.3% and 48.8% for adalimumab, and 90.5%, 91.8% and 88.9% for ustekinumab. Hazard ratios for comparisons were 0.20 (95% CI 0.05 to 0.84; p = 0,028) for ustekinumab versus etanercept, 0.18 (95% CI 0.045 to 0.77; p = 0.028) for ustekinumab versus adalimumab and 1.10 (95% CI 0.65 to 1.88; p = 0.720) for adalimumab versus etanercept. Estimated mean persistence time was 1.798 ± 205,1.525 ± 173 and 1.889 ± 106 days for etanercept, adalimumab and ustekinumab, respectively.

Conclusion Persistence was greater in Pso patients treated with ustekinumab than those achieved with etanercept or adalimumab. Time to discontinuation was similar between adalimumab and etanercept. Less than 50% of adalimumab patients persisted by the third year.

No conflict of interest.