Combination of Halobetasol Propionate and Tazarotene Lotion (Duobrii®) for Palmoplantar Plaque Type Psoriasis

Plaque type psoriasis of the hands and/or feet affects approximately 3-4% of patients with psoriasis. It is characterized by well-defined erythematous desquamative plaques located on the palms and soles, which may be limited to acral involvement or occur in combination with generalized psoriasis. Psoriasis that affects the hands and/or feet has a profound impact on quality of life (QoL) as it contributes to more physical disability and discomfort than patients with other forms of psoriasis, such as difficulty walking or using the hands.

Furthermore, psoriasis of the hands and/or feet is generally considered a therapeutic challenge because the thicker stratum corneum reduces the penetration of topical treatment agents. Systemic treatments (retinoids, psoralen-ultraviolet A \[PUVA\], methotrexate, cyclosporine, and biologic therapy) have shown limited efficacy on psoriasis in acral areas. Unfortunately, patients with hand and/or foot involvement often have too low of body surface area (BSA) to participate in clinical trials for new psoriasis treatments, resulting in limited studies among this sub-population and no clear treatment algorithm.

The high unmet need for an effective treatment for psoriasis of the hands and/or feet has been addressed in recent years with the development of new medications for generalized psoriasis that may also be effective in treating disease localized to acral areas. In 2015, two multicenter, double-blind, randomized, parallel-group phase 3 studies were conducted to assess the safety, tolerability, and efficacy of lotion containing a combination of halobetasol propionate 0.01% and tazarotene 0.045% (HP/TAZ). The study population was subjects with moderate-to-severe psoriasis. The study results found that treatment success (defined as at least a 2-grade improvement from baseline Investigator Global Assessment score and a score of clear or almost clear) was achieved in around 40% of subjects by week 8, with substantial reductions in affected BSA, improvement in QoL, and a significant reduction in signs and symptoms of psoriasis.

These phase 3 studies did not include a sub-analysis of the effect of HP/TAZ on psoriasis of the hands and/or feet. Given that topical steroids and topical retinoids are separately recommended as treatment options for psoriasis of the hands and/or feet, an agent that safely combines these medications - and that has demonstrated safety and efficacy in generalized psoriasis - offers a potential treatment for psoriasis of the hands and/or feet.

The purpose of the study described in this protocol is to evaluate the effect of HP/TAZ on plaque type psoriasis of the hands and/or feet after 24 weeks of daily treatment. In addition, given the impact of this variant of psoriasis on QoL and the relative lack of currently available treatment options, this study will also evaluate the impact of HP/TAZ treatment on patient-reported QoL measures and treatment satisfaction scoring.