[Therapeutic possibilities of recombinant interferon alfa-2b (Intron A) in non-AIDS Kaposi sarcomas and...

Data concerning treatment of vascular neoplasia with biological response modifiers are still scanty, but encouraging results have been observed with alpha-2b interferon in AIDS related Kaposi sarcoma. In this study five treatment naive patients with Kaposi sarcoma and four heavily pretreated patients with angiosarcoma with still evolutive disease were treated with Etopozid 120 mg/m2/24h, days 1, 3 and 5, and recombinant alpha-2b interferon 6.000.000 U/24h, days 1-15, the intercycle interval being 21-28 days. All patients were negative for anti-HIV 1, anti-HIV 2 and anti-HTLV 1 antibodies; one patient had a high titer of IgG anti-chlamydia antibodies amounting to 1/4.194.304. This group differed from similar HIV 1 positive patients by having a normal CD4/CD8 ratio. In the Kaposi sarcoma group 1/5 achieved a complete response lasting 24+ months and 3/5 achieved a good partial response lasting 5+, 12+ and 35+ months. In the angiosarcoma group 1/4 patient achieved a complete response but relapsed after 18 months and one patient experienced stable disease lasting for 15+ months. These findings could be understood in two different ways. Since an infective etiology has been proposed for Kaposi sarcoma, the positive effect of alpha-2b interferon could be related to its "antiinfective" effects observed in viral disorders. However, similar activity in angiosarcoma points to the possibility that the positive effect of alpha-2b interferon in this group of disorders is related to interfering effects of the drug with factors implicated in neoplastic angiogenesis.