SURROGATE END-POINTS IN CLINICAL-STUDIES, AS EXEMPLIFIED BY HIV-INFECTION

Surrogate endpoints are used extensively in clinical studies to evalua te the efficacy therapy. The effect of a treatment on surrogate endpoi nts should predict efficacy with regard to clinical endpoints such as morbidity and death. Benefits and risks in the use of surrogate endpoi nts in clinical trials and daily practice are discussed using the exam ple of HIV infection. CD4-lymphocyte counts and plasma HIV-RNA are pow erful markers of disease progression in HIV infection. They are also i ncreasingly used as surrogate endpoints to evaluate the efficacy of an tiretroviral treatments. Surrogate endpoints should be biologically pl ausible and must be validated statistically. However, clinical endpoin ts are still of paramount importance in assessing the value of treatme nts for chronic diseases.