The pharmacokinetics of lersivirine (UK-453,061) and HIV-1 protease inhibitor coadministration in healthy subjects

Investigational reverse transcriptase inhibitors for the treatment of HIV

INTRODUCTION

While considerable advances have been made in the development of antiretroviral agents, there is still work to be done. Reverse transcriptase inhibitors are important drugs for the treatment of HIV, and considerable research is currently ongoing to develop new agents and to modify currently existing agents.

AREAS COVERED

Herein, the authors discuss both investigational nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), including agents that are in various stages of development. They also discuss novel formulations that are being investigated for currently available drugs, and discuss the advantages that these new formulations may provide.

EXPERT OPINION

New formulations and co-formulations of currently existing antiretrovirals will represent an important area of development, as a means to improve adherence for HIV-positive individuals. New formulations will continue to be developed, with a focus on allowing for less-frequent administration, as well increasing drug concentrations at local sites such as vaginal tissue, rectal tissue and sites in the immune system.

Lersivirine - a new drug for HIV infection therapy

INTRODUCTION

Lersivirine (UK-453,061) is a novel second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI). It binds reverse transcriptase in a distinct way leading to a unique resistance profile. The development of lersivirine was recently stopped in Phase IIb clinical development.

AREAS COVERED

This article describes the background of lersivirine, its pharmacodynamic and pharmacokinetic profile and its clinical efficacy in HIV-infected patients. Moreover, the authors review its resistance profile in addition to its possible interactions with coadministered drugs and safety and tolerability. The authors' evaluation is based on the articles retrieved from a Medline in addition to abstracts from major HIV conferences and workshops addressing lersivirine.

EXPERT OPINION

The authors believe that lersivirine has therapeutic potential for HIV-infected individuals with viral strains resistant against first-line NNRTIs. However, no large, well-powered studies have been conducted so far, which assess noninferiority against established antiretroviral agents. In February 2013, the developing company behind lersivirine halted further development as it was decided that it would not provide an improvement over existing therapies; perhaps this is an opportunity missed.