Optimal clinical trial designs for immune-based therapies in persistent viral infections

There is now effective therapy for infection by the Human Immunodeficiency Virus (HIV), but there is no cure. Consequently, antiviral drugs must be administered continuously to suppress viral replication. Recently, a large phase III international immune-based therapy trial was discontinued because it is difficult to measure clinical endpoints while antivirals are administered. Since the immune system has evolved under the selective force of microbial infections, the immune reaction is antiviral. This commentary explores the rationale of using "Diagnostic Treatment Interruptions" of antiviral therapies to determine efficacies of immune-based therapies.