OBJECTIVES:

Psoriasis is an immune-mediated chronic skin disease that affects approximately 1-3% of Canadians, with plaque psoriasis (PsO) being the most common subtype. In addition to traditional topical monotherapies for PsO, combination products are available: halobetasol propionate plus tazarotene (HP/TAZ as lotion) and betamethasone dipropionate plus calcipotriol (BD/CAL as ointment, gel or foam formulations). This study aims to describe the demographic characteristics of Canadian patients who initiated one of the topical combination products following the notice of compliance issued by Health Canada for HP/TAZ in 2020.

METHODS:

This retrospective, observational study utilized IQVIA’s longitudinal Private Drug Plan database. Patients initiating topical combination from August 1^st, 2020 to May 31^st, 2021 were indexed on their first observed claim. Eligible patients were naïve to biologics, PsO oral drugs and index drugs within a 3-year lookback period prior to index. Patient demographics and prior therapy were categorized.

RESULTS:

A total of 23,084 eligible patients were selected and indexed on HP/TAZ (14.6%), BD/CAL ointment (24.6% including generic), BD/CAL gel (29.8%), and BD/CAL foam (31.0%). 52.6% were female and 81.3% were age 30-69 with an average age of 46.8 (SD 15.4).

In a subset analysis, 13,836 patients with full 3-year period prior to index were assessed. 54.6% of patients indexing on HP/TAZ had topical therapies prior to index, compared to those indexed on BD/CAL ointment (35.9%), gel (33.8%), and foam (46.1%). Among patients with prior topical therapies, 58.1% of HP/TAZ-indexed patients had ≥2 types of previous topical therapies compared to BD/CAL ointment (36.8%), gel (38.4%), and foam (45.0%).

CONCLUSIONS:

Patients indexed on HP/TAZ are more experienced on topical therapies at time of initiation than other combination products. However, given the recent availability of HP/TAZ, the need remains to understand the drug utilization among a larger cohort of PsO patients with a longer follow-up period.