HIV Entry Inhibitors: Entering the Treatment Paradigm

There are 21 antiretroviral drugs approved for the treatment of HIV infection. Current drugs fall into 3 mechanistic classes: the 2 traditional classes – HIV reverse transcriptase inhibitors and HIV protease inhibitors and the newest class – HIV entry inhibitors. Current antiretroviral regimens are effective in suppressing viral replication, enhancing immune function, and preventing clinical progression of HIV disease. However, current antiretroviral drugs may be compromised by suboptimal antiretroviral activity; drug resistance and cross-resistance; complexity; acute, chronic and life-threatening toxicities; and drug-drug interactions. Newer antiretroviral agents, such as the HIV entry inhibitors, are needed to improve antiretroviral activity (particularly against drug-resistant strains), avoid the selection of drug resistance, improve convenience, improve tolerability and reduce toxicity, and minimize drug-drug interactions. With demonstrated safety and effectiveness against drug-resistant viruses, HIV entry inhibitors quickly may become part of treatment regimens for treatment-experienced patients. With additional safety, tolerability, convenience, and antiretroviral activity data, HIV entry inhibitors could become part of standard treatment regimens for treatment-naïve patients.