Background A limited number of studies have evaluated medication adherence in psoriasis (PS) or psoriatic arthritis (PsA), reporting rates between 29% and 88% (medication possession ratio (MPR >80%)). However, until now no study has included apremilast as the evaluated drug.

Purpose To evaluate adherence to apremilast treatment in patients with PsO and PsA, and to assess the possible factors associated with a MPR <100%.

Material and methods Retrospective observational study including all patients beginning apremilast in an outpatient pharmacy service from a tertiary university hospital. Exclusion criteria: patients with less than one medication pharmacy refill (early discontinuation or recent treatment initiation).

Data collected demographics, treatment indication, previous biological treatment, incidence of adverse events (AE) and adherence to apremilast using the MPR.

Differences between patients with a MPR ≥100% vs. MPR <100% were evaluated in the univariate analysis.

Results Forty-one patients were included: 47 (23–68) years; male 56.1%; PsA 70.7%; and previous biologic therapy 26.8%. At least one adverse effect was reported in nine (21.9%) patients. Thirteen (31.7%) patients discontinued apremilast because of none-response, three (7.3%) for adverse events and one (2.4%) for loss of follow-up.

Adherence was: MPR 100% in 22 (53.7%), MPR 90%–99% in 11 (26.8%), MPR 80%–89% in four (9.8%), MPR 70%–79% in two (4.9%) and MPR <70% in two (4.9%) patients.

Conclusion

• Apremilast adherence rate was >90% in more than 80% of the patients.

• Considering MPR >80% reported in the literature, this rate was achieved in approximately 90% of patients, probably related to a multidisciplinary attention.

• The none factor was associated with a poorer adherence, however further studies including a greater number of patients are required.

References and/or acknowledgements No conflict of interest.