ABSTRACT
A series of 5-amino derivatives of 8-hydroxy[1,6]-naphthyridine-7-carboxamide exhibiting sub-micromolar potency against replication of HIV-1 in cell culture was identified. One of these analogs, compound 12, displayed excellent pharmacokinetic properties when dosed orally in rats and in monkeys. This compound was demonstrated to be efficacious against replication of simian-human immunodeficiency virus (SHIV) 89.6P in infected rhesus macaques.
Subject(s)
HIV Integrase Inhibitors/chemical synthesis , HIV Integrase Inhibitors/pharmacology , Naphthyridines/chemistry , Naphthyridines/pharmacology , Amination , HIV Integrase Inhibitors/chemistry , Molecular Structure , Naphthyridines/chemical synthesis , Structure-Activity RelationshipABSTRACT
We describe the efficacy of L-870812, an inhibitor of HIV-1 and SIV integrase, in rhesus macaques infected with the simian-human immunodeficiency virus (SHIV) 89.6P. When initiated before CD4 cell depletion, L-870812 therapy mediated a sustained suppression of viremia, preserving CD4 levels and permitting the induction of virus-specific cellular immunity. L-870812 was also active in chronic infection; however, the magnitude and durability of the effect varied in conjunction with the pretreatment immune response and viral load. These studies demonstrate integrase inhibitor activity in vivo and suggest that cellular immunity facilitates chemotherapeutic efficacy in retroviral infections.
Subject(s)
Acquired Immunodeficiency Syndrome/drug therapy , Acquired Immunodeficiency Syndrome/immunology , HIV-1/physiology , Integrase Inhibitors/therapeutic use , Naphthyridines/therapeutic use , Simian Acquired Immunodeficiency Syndrome/drug therapy , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Immunodeficiency Virus/physiology , Acquired Immunodeficiency Syndrome/virology , Animals , Anti-HIV Agents/administration & dosage , Anti-HIV Agents/blood , Anti-HIV Agents/pharmacology , Anti-HIV Agents/therapeutic use , CD4 Lymphocyte Count , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cells, Cultured , Drug Resistance, Viral , HIV Integrase/genetics , HIV Integrase/metabolism , HIV Integrase Inhibitors/administration & dosage , HIV Integrase Inhibitors/blood , HIV Integrase Inhibitors/pharmacology , HIV Integrase Inhibitors/therapeutic use , HIV-1/drug effects , HIV-1/enzymology , HIV-1/genetics , Immunity, Cellular , Integrase Inhibitors/administration & dosage , Integrase Inhibitors/blood , Integrase Inhibitors/pharmacology , Integrases/genetics , Integrases/metabolism , Leukocytes, Mononuclear/virology , Macaca mulatta , Mutation , Naphthyridines/administration & dosage , Naphthyridines/blood , Naphthyridines/pharmacology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/drug effects , Simian Immunodeficiency Virus/enzymology , Simian Immunodeficiency Virus/genetics , Viral Load , Viremia/drug therapy , Virus Replication/drug effectsABSTRACT
The increasing incidence of resistance to current HIV-1 therapy underscores the need to develop antiretroviral agents with new mechanisms of action. Integrase, one of three viral enzymes essential for HIV-1 replication, presents an important yet unexploited opportunity for drug development. We describe here the identification and characterization of L-870,810, a small-molecule inhibitor of HIV-1 integrase with potent antiviral activity in cell culture and good pharmacokinetic properties. L-870,810 is an inhibitor with an 8-hydroxy-(1,6)-naphthyridine-7-carboxamide pharmacophore. The compound inhibits HIV-1 integrase-mediated strand transfer, and its antiviral activity in vitro is a direct consequence of this ascribed effect on integration. L-870,810 is mechanistically identical to previously described inhibitors from the diketo acid series; however, viruses selected for resistance to L-870,810 contain mutations (integrase residues 72, 121, and 125) that uniquely confer resistance to the naphthyridine. Conversely, mutations associated with resistance to the diketo acid do not engender naphthyridine resistance. Importantly, the mutations associated with resistance to each of these inhibitors map to distinct regions within the integrase active site. Therefore, we propose a model of the two inhibitors that is consistent with this observation and suggests specific interactions with discrete binding sites for each ligand. These studies provide a structural basis and rationale for developing integrase inhibitors with the potential for unique and nonoverlapping resistance profiles.