Recent developments in vitamin D analogs

Within the past decade it has been shown that psoriasis can be treated topically with analogs of vitamin-D-3. Impaired differentiation and increased proliferation of keratinocytes are key features in psoriatic lesions together with a local activation of T lymphocytes. Evidence has accumulated showing that analogs of vitamin D-3 increase differentiation and inhibit proliferation of keratinocytes. Therefore, analogs of vitamin D-3 have been investigated in a number of trials showing improvement of psoriasis. It has been shown that vitamin D analogs are better than their vehicle and show the same potency as potent topical steroids. However, vitamin D analogs have been proven efficacious and without side effects also when used on long term basis. Vitamin D analogs can be used both as monotherapy and in combination topical steroids, UVB, PUVA, retinoids and cysclosporine. The vitamin D-3 analog calcipotriol has been investigated in most detail and is available as an ointment, a creme and as a scalp solutation. From clinical studies involving thousands of patients, it can be concluded that calcipotriol is efficacious, safe, well tolerated and can be used on a long term basis. Other analogs are available, however, these analogs have not been studied in greater details vet.