Challenges and approaches in the discovery of human immunodeficiency virus type-1 non-nucleoside reverse transcriptase inhibitors.

The type I human immunodeficiency virus (HIV-1) pandemic affecting over 37 million people worldwide continues, with 1.8 million people newly infected each year. Highly active antiretroviral therapy is efficient at reducing viral load and nearly one-half of the infected population is on treatment. One of the most successful approaches for the treatment of HIV infections is the use of inhibitors for human immunodeficiency virus type-1 reverse transcriptase (HIV-1 RT). At present, there are six nonnucleoside reverse transcriptase inhibitors (NNRTIs) approved for clinical use: nevirapine (NVP), delavirdine (DLV), efavirenz (EFV), etravirine (ETV), rilpivirine (RPV), and elsulfavirine. In this review, we will cover the development of different classes of NNRTIs over the last two decades. We will give an overview of traditional medicinal chemistry strategies for structural modification as bioisosterism principles, scaffold hopping, substitute decoration, and molecular hybridization. Furthermore, computer-aid design as virtual screening, de novo design and free-energy perturbation will be described in details.