A Diarylsulphone Non-Nucleoside Reverse Transcriptase Inhibitor with a Unique Sensitivity Profile to Drug-Resistant Virus Isolates

Abstract

Structure-activity relationship evaluations with a series of diarylsulphone non-nucleoside reverse transcriptase (RT) inhibitors indicated that the steric properties of the molecule and compound lipophilicity primarily contributed to the overall level of activity of the compounds against human immunodeficiency virus type 1 (HIV-1). The most active compounds in the diarylsulphone series had an orthonitro group and yielded anti-HIV activity at sub-micromolar concentrations. Compounds of the diarylsulphone class exhibited antiviral properties similar to other members of the pharmacologic class of HIV-1 specific non-nucleoside reverse transcriptase inhibitors, including activity in a wide variety of established and primary human cells, activity against a wide variety of laboratory and clinical virus isolates, and activity when challenged at high multiplicity of infection. Synergistic inhibition of HIV-1 was observed when the diarylsulphone NSC 667952 was used with the nucleoside analogues AZT, ddl, 3TC and d4T, the protease inhibitor KNI 272 and the sulphonated dye resobene; additive effects were observed when NSC 667952 was used with the nucleoside analogue ddC and other non-nucleoside RT inhibitors. The diarylsulphones exhibited a unique sensitivity profile when evaluated against both virus isolates and purified reverse transcriptase containing non-nucleoside reverse transcriptase inhibitor resistance-engendering mutations. Unlike other members of the class of non-nucleoside compounds, NSC 667952 remained active against virus isolates with the L100I amino acid change in the RT. The compound was, however, highly sensitive to Y181C., K103N and K101E amino acid changes in the RT. The diarylsulphone selected for resistant virus populations which possessed the Y181C amino acid change in the reverse transcriptase and which exhibited enhanced sensitivity to the non-nucleoside inhibitors calanolide A and costatolide.