OBJECTIVES : Plaque psoriasis is undertreated in Canada, with some severely-affected patients receiving no treatment at all. Halobetasol propionate (0.01%) and tazarotene (0.045%) (HP/TAZ) is the first topical combination therapy in a once-daily lotion formulation of corticosteroid/retinoid that has demonstrated efficacy and safety in two pivotal randomized controlled trials (RCTs). To inform Canadian submissions for reimbursement, a network meta-analysis (NMA) was undertaken to determine the efficacy of HP/TAZ fixed combination relative to other topical therapies among patients with moderate-to-severe plaque psoriasis.

METHODS : The NMA was informed by a systematic literature review that identified RCTs published between Jan-2000 and Oct-2019 of topical therapies approved in Canada for the management of plaque psoriasis (very high potency corticosteroids [VHPC], vitamin D analogues [VDA], betamethasone dipropionate/calcipotriol (BD/VDA), high potency corticosteroids [HPC], and tazarotene [TAZ]). Studies that had at least 70% of patients with moderate-to-severe plaque psoriasis and had reported treatment success (“clear” or “almost clear” score in the Investigator Global Assessment [IGA] or equivalent scale) were included in the NMA. Efficacy was evaluated at 8 weeks as this was the treatment duration in the HP/TAZ RCTs. A random effects models was selected a priori.

RESULTS : Fourteen studies contributed evidence to the NMA; no evidence was identified for HPC. With respect to vehicle, the relative risk (RR) of achieving treatment success was 4.3 (95% credible interval: 3.2, 5.5) for HP/TAZ; 4.2 (3.3, 5.2) for BD/VDA; 3.2 (2.5, 4.0) for VHPC; 1.9 (1.6, 2.4) for VDA; and 1.7 (0.8, 3.2) for TAZ. HP/TAZ and BD/VDA credible intervals were overlapping. The between-study standard deviation was 0.2 (0.0, 0.5).

CONCLUSIONS : Evidence suggests that HP/TAZ is more efficacious than topical monotherapies currently used in Canada. Based on this study’s findings, HP/TAZ’s efficacy is similar to that of BD/VDA and it provides a new important and needed treatment option for a currently undermanaged patient population.