Management of AIDS-related Kaposi's sarcoma: advances in target discovery and treatment

Kaposi's sarcoma is the most common tumor arising in HIV-infected patients and is an AIDS-defining illness by the Centers for Disease Control guidelines. Recent advances in the elucidation of the pathogenesis of KS are uncovering potential targets for KS therapies. Such targets include the processes of angiogenesis and cellular differentiation and the Kaposi's sarcoma herpesvirus/human herpesvirus-8. With the increasing recognition that effective antiretroviral regimens are associated with both a decreased proportion of new AIDS-defining Kaposi's sarcoma cases and a regression in the size of existing Kaposi's sarcoma lesions, most, if not all, Kaposi's sarcoma patients should be advised to take antiretroviral drugs that will maximally decrease HIV-1 viral load. Five agents are currently approved by the US FDA for the treatment of Kaposi's sarcoma; alitretinoin gel for topical administration; and liposomal daunorubicin, liposomal doxorubicin, paclitaxel and interferon-alpha for systemic administration. Many more agents, particularly angiogenesis inhibitors and other pathogenesis-targeted therapies are in early clinical development. Over the next 5 years, we may see even more of these pathogenesis-targeted therapies in trials and just as important we may identify, develop and validate clinically practical tools for assessing the biological effects of these therapies. The next 5 years may also bring a better understanding of the pharmacokinetic interactions among the many agents in the Kaposi's sarcoma and AIDS armamentariums.