Multicenter Pilot Study To Define The Marker As An Alternate For Tropism Assay

Treatment-experienced subjects on failed therapy, with HIV RNA ≥ 1000 copies/mL, are eligible who will receive a tropism assay at screening (Day -14 to 0). Subjects who are eligible will receive maraviroc added to a failing regimen from Day 1 to 14. On day 15, subjects will discontinue the current treatment regimen and begin a new OBT. Subjects with only R5 HIV will continue receiving maraviroc plus OBT. Subjects with non-R5 virus will discontinue receiving maraviroc but continue to receive the new OBT. Investigator selects OBT based on results of phenotype/genotype testing at baseline. The nominal dose for maraviroc is 300 mg BID. The maraviroc dose should be adjusted based on OBT patient is taking. If OBT includes CYP3A4 inhibitor (with or without inducers) maraviroc dose should be 150 mg BID and if OBT includes CYP3A4 inducer (without inhibitors) maraviroc dose should be 600mg BID. If OBT does not include any CYP3A4 inducers or inhibitors maraviroc dose should be 300 mg BID.

Trofile Assay and HIV RNA quantification assay