General Information

Duobrii is a combination of halobetasol propionate, a corticosteroid and tazarotene, a retinoid prodrug.

Duobrii is specifically indicated for the topical treatment of plaque psoriasis in adults.

Duobrii is supplied as a lotion for topical administration. Each gram of Duobrii Lotion contains 0.1 mg (0.01%) halobetasol propionate and 0.45 mg (0.045%) tazarotene. Apply a thin layer of Duobrii Lotion once daily to cover only affected areas and rub in gently. If a bath or shower is taken prior to application, the skin should be dry before applying the lotion. The total dosage should not exceed approximately 50 g per week because of the potential for the drug to suppress the hypothalamicpituitary-adrenal (HPA) axis. Do not use with occlusive dressings unless directed by a physician. Discontinue treatment when control is achieved. Avoid application of Duobrii Lotion on the face, groin, or in the axillae.

Mechanism of Action

Duobrii is a combination of halobetasol propionate, a corticosteroid and tazarotene, a retinoid prodrug. Corticosteroids play a role in cellular signaling, immune function, inflammation, and protein regulation; however, the precise mechanism of action in plaque psoriasis is unknown. Tazarotene is a retinoid prodrug which is converted to its active form, tazarotenic acid, the carboxylic acid of tazarotene, by deesterification. Tazarotenic acid binds to all three members of the retinoic acid receptor (RAR) family: RARα, RARβ and RARγ, but shows relative selectivity for RARβ, and RARγ and may modify gene expression. The clinical significance of these findings for the treatment of plaque psoriasis is unknown.

Clinical Trial Results

The FDA approval of Duobrii was based on three studies.

Studies 1 and 2, which enrolled a total of 418 patients, showed Duobrii was consistently more effective than vehicle in achieving treatment success (primary endpoint at eight weeks), demonstrating statistically significant superiority by week four (in Study 1) and week two (in Study 2). At week eight, 36 percent (Study 1) and 45 percent (Study 2) had achieved the primary efficacy outcome, compared to seven percent and 13 percent on vehicle (both p<0.001). The majority of responders maintained treatment success over the four-week post treatment period. A third Phase 3 multicenter, open-label study assessed the long term safety of Duobrii over a year in subjects with plaque psoriasis. Patients were given Duobrii once daily for eight weeks and re-evaluated every four weeks after for a year. Continuous treatment was allowed up to 24 weeks and as needed for up to 52 weeks. Treatment related adverse events > two percent were application site reactions such as itching, pain, irritation and inflamed hair follicles (folliculitis).