An Open Label Pharmacokinetic, Safety And Efficacy Study Of Maraviroc In Combination With Background Therapy For The Treatment Of HIV-1 Infected, CCR5 -Tropic Children

Inclusion Criteria:

- Subjects who are 2-18 years of age, treatment experienced for 6 months or longer with
at least 2 ARV drug classes, with HIV-1 RNA ≥1,000 copies/mL

Exclusion Criteria:

- X4- or dual/mixed-tropic virus detected by the Trofile™ viral tropism assay

- Concomitant therapy with other investigational agents (other than experimental ARV
agents available through pre-approval access programs)

- Known ≥Grade 3 of any of the following laboratory tests at Screening or within 30 days
prior to Baseline Visit: Neutrophil count, hemoglobin, platelets, AST, ALT, and
creatinine, lipase;

- Total bilirubin ≥Grade 3, unless ALL of the following are true: Current regimen
includes atazanavir; ALT/AST < 2.5 X ULN; No symptoms other than jaundice or icterus.

- Other laboratory values ≥Grade 3, must be reviewed by Pfizer.