Kenneth A. Smiles

The effect of intralesional interferon gamma on basal cell carcinomas.

This open label study evaluated the effect of nine intralesional injections of two different doses of interferon gamma on basal cell carcinomas in 29 patients. One group of 15 patients received interferon gamma, 0.01 mg (20,000 IU), intralesionally three times a week for 3 weeks. Fourteen patients received interferon gamma, 0.05 mg (100,000 IU), intralesionally in the same dosage schedule. Excisional biopsy specimens 12 weeks after therapy showed no evidence of tumor remaining in 7 of 14 patients (50%) treated with the higher dose of interferon gamma, whereas only 1 of 15 patients (7%) treated with low-dose interferon gamma was cured according to histologic criteria (p = 0.025). Seventy-six percent of patients reported at least one adverse reaction, but most were considered mild by the patient and the investigator.

Intralesional interferon in the treatment of early mycosis fungoides

Twelve patients with early mycosis fungoides were enrolled in a randomized, double-blind, placebo-controlled study. Isolated plaques were injected three times a week with recombinant alpha 2-interferon in nine patients and with the vehicle in three patients. Two additional plaques were evaluated in each patient; one was left untreated, and another was treated topically with either placebo ointment or betamethasone ointment. Biopsies were taken from an untreated, representative plaque prior to treatment and from all test sites following treatment for light microscopy and T lymphocyte subsets. Three of the nine lesions injected with interferon cleared, and all showed improvement. Thirteen of eighteen noninjected lesions improved in patients who received interferon, showing a systemic effect. In the control group, none of the injected lesions improved and only two of the noninjected lesions showed any change. Histopathologic changes confirmed the clinical impression. This study shows that intralesional interferon may be given safely and has a beneficial effect, both locally and systemically.

Intralesional interferon alfa-2b for the treatment of genital warts

A randomized, double-blind, placebo-controlled study has been conducted, and intralesional interferon alfa-2b was tested in the treatment of genital warts. This study design was to give 1 million units interferon alfa-2b intralesionally into the base of each of five external genital warts per patient, on a Monday-Wednesday-Friday treatment schedule for 3 weeks (total of nine injections). Forty-two patients were entered (20 randomized to receive interferon and 22 placebo injections). There were 43.8% of patients on the interferon treatment arm of the double-blind portion of the study who had complete disappearance of all warts, with an additional 25% of patients showing greater than 50% shrinkage of visible warts. On the placebo arm 14.3% showed a complete response, with an additional 14.3% showing greater than 50% shrinkage. This difference between interferon and placebo treatment was statistically significant (p less than 0.03). We conclude that intralesional interferon alfa-2b has significant activity in the treatment of genital warts.

Topical protection against long-wave ultraviolet A

A PABA ester-oxybenzone preparation is superior to PABA or sulisobenzone alone in protecting the skin from methoxsalen-induced ultraviolet A (UVA) phototoxicity after water substantivity challenge. Such a mixture would be useful as a UVA screen for uninvolved or actinically damaged skin in patients receiving psoralens and ultraviolet A (PUVA) therapy. An effective topical UVA screen also may protect against UVA-induced diseases like solar urticaria, polymorphic light eruptions, drug-induced phototoxicity or photoallergy, and possibly against the deep degenerative changes of solar elastosis.

Activity of Intralesional Interferon Alfa-2b in Viral and Malignant Skin Diseases

Interferon alfa-2b (Intron A®) is a highly purified single molecular species of alpha interferon and represents one of the more than twenty that exist naturally in man (1). It is produced using recombinant DNA techniques in the bacterium E. coli and is purified to a specific activity of approximately 2x100 IU/mg of protein. In common with the other alpha interferons, it has potent antiviral and antiproliferative properties when tested in vitro using human cell lines and viruses (2–4). Additionally, it causes the activation of natural killer cells (5), can restore cytotoxicity to functionally deficient monocytes (5), and like other alpha interferons would be expected to enhance antigen expression on cell surfaces (6). These properties suggested that interferon alfa-2b might have clinical utility in treating viral and malignant diseases in man. The ability to achieve high local concentrations in the skin by intralesional injection with comparatively little systemic exposure suggested further that malignant and premalignant skin diseases and those of a viral etiology might be especially amenable to treatment with interferon alfa-2b.