Trial of Maraviroc (UK-427,857) in Combination With Optimized Background Therapy Versus Optimized Background Therapy Alone for the Treatment of HIV-1 Infected Subjects

Percentage of Participants With HIV-1 RNA Levels Less Than 400 Copies/mL

Time frame: Week 24 and 48

Percentage of Participants With HIV-1 RNA Levels Less Than 400 Copies/mL or With at Least 0.5 log10 Decrease From Baseline

Time frame: Week 24 and 48

Percentage of Participants With HIV-1 RNA Levels Less Than 400 Copies/mL or With at Least 1.0 log10 Decrease From Baseline

Time frame: Week 24 and 48

Percentage of Participants With HIV-1 RNA Levels Less Than 50 Copies/mL

Time frame: Week 24 and 48

Cluster of Differentiation 4 (CD4) and Cluster of Differentiation 8 (CD8) Cell Count at Baseline

Baseline value calculated as average of pre-dose measurements collected at screening and immediately pre-dose.

Time frame: Baseline

Change From Baseline in CD4 Cell Count at Week 24 and 48

Change from baseline in CD4 cell count measured as cells/µL. Baseline value calculated as the average of pre-dose measurements collected at screening and immediately pre-dose.

Time frame: Baseline, Week 24 and 48

Change From Baseline in CD8 Cell Count at Week 24 and 48

Change from baseline in CD8 cell count measured as cells/µL. Baseline value calculated as the average of pre-dose measurements collected at screening and immediately pre-dose.

Time frame: Baseline, Week 24 and 48

Time to Virological Failure

Time to virologic failure based on observed HIV-1 RNA levels and failure events (death;permanent discontinuation of drug;lost to follow-up \[LTFU\];new anti-retroviral drug added \[except background drug change to drug of same class\];or on open label for early non-response or rebound). Failure:at Time 0 if level not \<400 copies/mL(2 consecutive visits) before events or last available visit;at time of earliest event if level \<400 copies/mL(2 consecutive visits);failure if level \>=400 copies/mL(2 consecutive visits) or 1 visit \>=400 copies/mL followed by permanent discontinuation of drug or LTFU.

Time frame: Week 48

Time-Averaged Difference (TAD) From Baseline in log10 Transformed HIV-1 RNA Levels

TAD from baseline was calculated as area under the curve of HIV-1 RNA load (log10 copies/mL) divided by time period minus baseline HIV-1 RNA load (log10 copies/mL). Baseline value calculated as the average of pre-dose measurements collected at screening, randomization, and immediately pre-dose.

Time frame: Baseline to Week 24 and Week 48

Number of Participants With Genotypic Susceptibility Scores (GSS) and Phenotypic Susceptibility Score (PSS) at Screening

Number of participants with GSS and PSS were used as surrogates for assessing genotype and phenotype. Genotypic and phenotypic resistance to protease inhibitors(PIs), nucleoside reverse transcriptase inhibitors(NRTIs), non-nucleoside reverse transcriptase inhibitors(NNRTIs) were evaluated at screening (not at baseline), by Monogram Biosciences PhenoSense genotyping (GT) assay. Score was determined for each drug in OBT, giving 1:drug 'sensitive'/'susceptible' and 0:'resistant'. GSS and PSS score range:0 to \>3. Genotypic enfuvirtide value was used for PSS, no phenotypic enfuvirtide was recorded.

Time frame: Screening

Number of Participants With Change in GSS and PSS From Screening at the Time of Treatment Failure Through Week 24

Number of participants with GSS and PSS were used as surrogates for assessing genotype and phenotype. Genotypic and phenotypic resistance to PIs, NRTIs and NNRTIs were evaluated at screening and time of treatment failure analyzed through week 24 visit, by Monogram Biosciences PhenoSense GT assay. Score was determined for each drug in OBT, giving 1: drug 'sensitive'/'susceptible' and 0: 'resistant'. GSS and PSS score range:0 to \>3. Genotypic enfuvirtide value was used for PSS, no phenotypic enfuvirtide was recorded.

Time frame: Screening and time of failure through week 24

Number of Participants With Change in GSS and PSS From Screening at the Time of Treatment Failure at Week 48

Number of participants with GSS and PSS were used as surrogates for assessing genotype and phenotype. Genotypic and phenotypic resistance to PIs, NRTIs and NNRTIs were evaluated at screening and time of treatment failure analyzed through week 48 visit, by Monogram Biosciences PhenoSense GT assay. Score was determined for each drug in OBT, giving 1: drug 'sensitive'/'susceptible' and 0: 'resistant'. GSS and PSS score range:0 to \>3. Genotypic enfuvirtide value was used for PSS, no phenotypic enfuvirtide was recorded.

Time frame: Screening and time of failure through week 48

Number of Participants Per Tropism Status at Baseline and at the Time of Treatment Failure Through Week 24

Number of participants per tropism status (C-X-C chemokine receptor 5 {CCR5} \[R5\], C-X-C chemokine receptor type 4 {CXCR4} \[X4\], Dual/mixed \[DM\], or Non-reportable/Non-phenotypable \[NR/NP\]) at baseline and time of treatment failure analyzed through week 24 visit. Treatment failure defined as discontinuation due to insufficient clinical response. HIV-1 RNA viral load \<500 copies/mL categorized as below lower limit of quantification (BLQ). The assessment for time of treatment failure was defined as the last on treatment assessment.

Time frame: Baseline and time of failure through week 24

Number of Participants Per Tropism Status at Baseline and at the Time of Treatment Failure Through Week 48

Number of participants per tropism status (R5, X4, DM, or NR/NP) at baseline and time of treatment failure analyzed through week 48 visit. Treatment failure defined as insufficient clinical response. HIV-1 RNA viral load \<500 copies/mL categorized as BLQ. The assessment for time of treatment failure was defined as the last on treatment assessment.

Time frame: Baseline and time of failure through week 48

Change From Baseline in Viral Load at Week 24 and Week 48 by Overall Susceptibility Score (OSS) at Screening

Association between baseline resistance and virological response was assessed as change in viral load by OSS at screening. OSS categorized as 0, 1, 2, \>3 (maximum value of 6) and calculated as the sum of the net assessment of in-vitro phenotypic and genotypic susceptibility using a binary scoring system (0= resistant, 1= sensitive or susceptible) for each antiretroviral agent in OBT. Higher scores indicate greater susceptibility. Baseline value is the average of the values from screening, randomization and immediately pre-dose.

Time frame: Baseline, Week 24 and Week 48