Maraviroc (UK-427,857), a selective and reversible CCR5 co-receptor antagonist, has been shown to be active in vitro against a wide range of clinical isolates (including those resistant to existing classes). In HIV-1 infected patients in the United States, maraviroc (UK-427,857) is approved for use as part of combination antiretroviral treatment in treatment-experienced and treatment-naive adult subjects. At least 50% of treatment-experienced patients are infected with R5-tropic HIV-1 exclusively. However, even in patients infected with a dual tropic (R5 + X4) phenotype, a large proportion of the virus population still uses CCR5 exclusively. Thus, the purpose of this study is to evaluate the antiretroviral activity, and safety, of maraviroc (UK-427,857) (in combination with other agents) in HIV infected, treatment experienced patients who are failing their current antiretroviral regimen and not infected with R5-tropic virus exclusively. This study will involve more than 200 centers globally to achieve a total randomized subject population of 192 subjects. Patients will be randomly (1:1:1) assigned to one of three groups: Optimized Background Therapy \[OBT (3-6 drugs based on treatment history and resistance testing)\] + maraviroc (UK-427,857) 150 mg taken once daily, OBT + maraviroc (UK-427,857) 150 mg taken twice daily, or OBT alone. Randomization was stratified by Enfuvirtide use in OBT (yes/no) and Screening HIV-1 RNA level (viral load) (\<100,000/≥ 100, 000 copies per milliliter \[copies per mL\]). The study will enroll over approximately a 9 month period with 48 weeks of treatment. Physical examinations will be performed at study entry, weeks 4, 8, 12, 16, 20, 24, 32, 40 and 48. Blood samples will also be taken at study entry, weeks 2, 4, 8, 12, 16, 20, 24, 32, 40, and 48. Additionally, blood samples will be drawn twice, at least 30 minutes apart, at weeks 2 and 24 for maraviroc (UK-427,857) pharmacokinetic analysis. As part of this clinical study a blood sample will also be taken for non-anonymized pharmacogenetic analysis. Patients will undergo a 12-lead electrocardiogram at study entry, weeks 24 and 48.
(i) Subjects remained on their assigned therapy for 48 weeks, unless the subject was discontinued early for protocol-defined treatment failure or other reasons such as adverse event, loss to follow-up, withdrawal of consent, or death. (ii) If a subject met the criteria for treatment failure or discontinued for another reason (eg, pregnancy, adverse event) and required an alternative regimen, the subject was followed until the Week 48 visit according to protocol guidelines. The new regimen, selected by the Investigator based on the results of resistance testing at the time of failure, had to be recorded in the CRF. (iii) Open-label maraviroc (UK-427,857) was provided by the sponsor, until it was commercially available, to subjects who completed 48 weeks of therapy and for whom it was medically appropriate to continue therapy with maraviroc (UK-427,857).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
190
OBT (3-6 drugs based on treatment history and resistance testing)
maraviroc (UK-427,857) 150 mg taken once daily
OBT (3-6 drugs based on treatment history and resistance testing)
maraviroc (UK-427,857) 150 mg taken twice daily
OBT (3-6 drugs based on treatment history and resistance testing)
Pfizer Investigational Site
Birmingham, Alabama, United States
Pfizer Investigational Site
Phoenix, Arizona, United States
Pfizer Investigational Site
Beverly Hills, California, United States
Pfizer Investigational Site
Fountain Valley, California, United States
Pfizer Investigational Site
Hayward, California, United States
Change From Baseline in Human Immunodeficiency Virus (HIV-1) Viral Load (Ribonucleic Acid [RNA])
Change from baseline in log 10-transformed plasma viral load (HIV-1 RNA) levels (log 10 copies per milliliter \[log10 copies/mL\]). Baseline value calculated as average of pre-dose measurements collected at screening, randomization, and baseline visits.
Time frame: Baseline to Week 24 and Week 48
Number of Subjects With HIV-1 RNA Levels < 400 Copies/mL
Time frame: Week 24, Week 48
Number of Subjects With HIV-1 RNA Levels < 400 Copies/mL or at Least 0.5 Log 10-transformed Decrease From Baseline in HIV-1 RNA Levels
Number of subjects with HIV-1 RNA levels \< 400 copies/mL or at least 0.5 log 10-transformed decrease from baseline in HIV-1 RNA levels. Baseline value calculated as average of pre-dose measurements collected at screening, randomization, and baseline visits.
Time frame: Baseline, Week 24, Week 48
Number of Subjects With HIV-1 RNA Levels < 400 Copies/mL or at Least 1.0 Log 10-transformed Decrease From Baseline in HIV-1 RNA Levels
Number of subjects with HIV-1 RNA levels \< 400 copies/mL or at least 1.0 log 10-transformed decrease from baseline in HIV-1 RNA levels. Baseline value calculated as average of pre-dose measurements collected at screening, randomization, and baseline visits.
Time frame: Baseline, Week 24, Week 48
Number of Subjects With HIV-1 RNA Levels < 50 Copies/mL
Time frame: Baseline, Week 24, Week 48
Change From Baseline in CD4 Cell Count
Change from baseline in CD4 cell count (measured as cells per microliter \[cells/µL\]). Baseline value calculated as the average of pre-dose measurements collected at screening, randomization, and baseline visits.
Time frame: Baseline to Week 24 and Week 48
Change From Baseline in CD8 Cell Count
Change from baseline in CD8 cell count (measured as cells/µL). Baseline value calculated as the average of pre-dose measurements collected at screening, randomization, and baseline visits.
Time frame: Baseline to Week 24 and Week 48
Time (50% Quartile Point Estimate) to Virologic Failure
Time to virologic failure based on observed HIV-1 RNA levels and failure events (death; permanent discontinuation of test drug \[perm DC\]; 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 event(s) or last available visit; at time of earliest event if level \<400 copies/mL (on 2 consecutive visits); failure if level ≥400 copies/mL (2 consecutive visits) or 1 visit ≥400 copies/mL followed by perm DC or LTFU.
Time frame: Day 1 through Week 24 and through Week 48
Change From Baseline in Time Averaged Difference (TAD) in log10 HIV-1 RNA
Change from baseline of TAD in log10 HIV-1 RNA viral load calculated as \[AUC of HIV-1 RNA viral load (log10 copies/mL) / time period\] - Baseline HIV-1 RNA viral load (log10 copies/mL). Baseline value calculated as the average of pre-dose measurements collected at screening, randomization, and baseline visits.
Time frame: Baseline to Week 24 and Week 48
Number of Subjects Per Genotype and Phenotype at Baseline and at Time of Failure
Number of subjects per genotype and phenotype (tests for presence of non CCR5-tropic HIV-1 and for resistance to reverse transcriptase, protease, and fusion inhibitors) at baseline and at time of failure through Week 48 visit. Sensitivity to drug categorized as 0-1, 2-4, \>4; scores defined as 0=resistance, 1=sensitive or susceptible with higher number indicating greater sensitivity or susceptibility.
Time frame: Baseline through Week 48
Number of Subjects Per Tropism Status at Screening and at the Time of Treatment Failure (Analysis at Week 24)
Number of subjects per Tropism status (CCR5 \[R5\], CXCR4 \[X4\], Dual Mixed \[DM\], or Non-reportable/Non-phenotypable \[NR/NP\]) at Screening (Scr) and at time of treatment failure (Tx fail). Treatment failure defined as insufficient clinical response. HIV-1 RNA viral load \<500 copies/ml categorized as below lower limit of quantification (BLQ). Tropism may have been assessed at either the Screening or Baseline visit. The assessment for time of treatment failure is defined as the last on-treatment assessment.
Time frame: Screening through Week 24
Number of Subjects Per Tropism Status at Screening and Time of Treatment Failure (Analysis at Week 48)
Number of subjects per Tropism status (CCR5 \[R5\], CXCR4 \[X4\], Dual Mixed \[DM\], or Non-reportable/Non-phenotypable \[NR/NP\]) at Screening (Scr) and at time of treatment failure (Tx fail). Treatment failure defined as insufficient clinical response. HIV-1 RNA viral load \<500 copies/ml categorized as below lower limit of quantification (BLQ). Tropism may have been assessed at either the Screening or Baseline visit. The assessment for time of treatment failure is defined as the last on-treatment assessment.
Time frame: Screening through Week 48
Number of Subjects With Treatment Failure at Week 24 by Overall Susceptibility Score (OSS) at Screening
Number of subjects for association between screening resistance and virologic response as determined by treatment failure and OSS at screening. OSS categorized as 0-1, 2-4, \>4 (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= reduced susceptibility, 1=susceptible) for each antiretroviral agent in OBT. Higher scores indicate greater susceptibility.
Time frame: Screening, Week 24
Number of Subjects With Treatment Failure at Week 48 by Overall Susceptibility Score (OSS) at Screening
Number of subjects for association between screening resistance and virologic response as determined by treatment failure and OSS at screening. OSS categorized as 0, 1, 2, or ≥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= reduced susceptibility, 1=susceptible) for each antiretroviral agent in OBT. Higher scores indicate greater susceptibility.
Time frame: Screening, Week48
Number of Subjects With Acquired Immunodeficiency Syndrome (AIDS)-Defining Opportunistic Illnesses (Analysis at Week 24)
Number of subjects with AIDS-defining opportunistic illnesses based on investigator classification guided by a predefined list of clinical Category C Adverse Events per Center for Disease Control (CDC) HIV Classification System. Includes events occurring up to 7 days after last dose of study drug.
Time frame: Baseline through Week 24
Number of Subjects With Acquired Immunodeficiency Syndrome (AIDS)-Defining Opportunistic Illnesses (Analysis at Week 48)
Number of subjects with AIDS-defining opportunistic illnesses based on investigator classification guided by a predefined list of clinical Category C Adverse Events per CDC HIV Classification System. Includes events occurring up to 7 days after last dose of study drug.
Time frame: Baseline through Week 48
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Pfizer Investigational Site
Los Angeles, California, United States
Pfizer Investigational Site
Los Angeles, California, United States
Pfizer Investigational Site
Los Angeles, California, United States
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Newport Beach, California, United States
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Oakland, California, United States
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