Efficacy and safety of a new combination of calcipotriol and betamethasone dipropionate (once or twice daily) compared to calcipotriol (twice daily) in the treatment of psoriasis vulgaris: a randomized, double-blind, vehicle-controlled clinical trial

BACKGROUND

Calcipotriol and betamethasone dipropionate are both widely used, effective treatments for psoriasis. Vitamin D analogues and topical corticosteroids have different mechanisms of action in the treatment of psoriasis. A new vehicle has been developed in order to contain both calcipotriol (50 micro g g-1) and betamethasone dipropionate (0.5 mg g-1) in an ointment form. By using calcipotriol and a corticosteroid together, greater efficacy may be achieved than by using either compound alone.

OBJECTIVES

The present study was conducted in order to compare the clinical efficacy and safety of the combined ointment formulation used once daily with the vehicle ointment used twice daily, calcipotriol ointment used twice daily and the combined formulation used twice daily in psoriasis vulgaris.

METHODS

This was an international, multicentre, prospective, randomized, double-blind, vehicle-controlled, parallel group, 4-week study in patients with psoriasis vulgaris amenable to topical treatment. Patients were randomized to one of four treatment groups: combined formulation once daily, combined formulation twice daily, calcipotriol twice daily or vehicle twice daily. Efficacy and safety were assessed.

RESULTS

There was no statistically significant difference in the mean percentage change in the Psoriasis Area and Severity Index (PASI) from baseline to end of treatment between the two combined formulation groups, but the difference in PASI reduction was significantly higher in the combined formulation groups (68.6% once daily, 73.8% twice daily) than in both the twice daily calcipotriol group (58.8%) and the vehicle group (26.6%). Safety data showed the frequency of adverse events to be less in the combined formulation groups than in both the calcipotriol group and the vehicle group. The proportion of patients with lesional/perilesional adverse reactions was less in the combined formulation groups and vehicle group than in the calcipotriol group (9.9% combined formulation once daily, 10.6% combined formulation twice daily, 19.8% calcipotriol, 12.5% vehicle).

CONCLUSIONS

No statistically significant nor clinically relevant difference in efficacy was seen between the combined formulation used once daily and twice daily. When compared to vehicle ointment or calcipotriol ointment alone, the combined formulation was shown to be clearly more efficacious.

Psoriasis: the future

The aetiology of psoriasis is still unclear but our knowledge of the psoriatic process has grown substantially over the last two decades. The future will undoubtedly bring advances in our understanding of the pathogenesis of psoriasis and, as a consequence, new therapies. Defining the molecular genetics of psoriasis will enhance our understanding of the disease process and hopefully facilitate the development of a representative animal model. This in itself will be a key step in the development and testing of new therapies. Precise identification of the immunological events involved in psoriasis will allow specific T-cell- and cytokine-targeted, and perhaps less toxic. immunotherapies. Anti-angiogenic agents that are in development for use in oncology may also be effective in psoriasis. The adaptation of current topical therapies such as retinoids and vitamin D analogues to produce more effective and better-tolerated formulations will also play a significant role in our future first-line management of patients. The increased recognition and better management of environmental trigger factors such as psychological distress will become an important factor in future psoriasis care. The development of physical therapies including photodynamic therapy and excimer lasers has the potential to expand the remit of psoriasis therapy. There is little doubt that the future for our patients with psoriasis is bright. However, this will only be achievable by a concerted research effort to understand all facets of this enigmatic disease ranging from the molecular to the environmental.