48-Week Study Of GW433908 And Ritonavir Or GW433908 Alone, Twice Daily In Pediatric Patients With HIV Infection

Plasma samples were assayed for APV concentrations using a validated assay. The GlaxoSmithKline (GSK) Department of Clinical Pharmacology Modeling and Simulation conducted pharmacokinetic (PK) analysis of the plasma APV concentration-time data using a model-independent approach. As a measure of total drug exposure, the area under the plasma-concentration-versus-time curve over the dosing interval at steady-state (AUC[0-τ]), where τ is the length of the dosing interval, was calculated by the linear up/log down trapezoidal method. hr, hour; µg, micrograms; mL, milliliter.

The maximum concentration at steady state (Cmax) was measured.

The plasma concentration at the end of the dosing interval at steady-state (Cτ) was measured.

Apparent clearance of drug from plasma following extravascular administration (CL/F) was calculated using the formulation: APV Dose in mg/kg units divided by AUC(0-τ). For FPV, doses were expressed in APV molar equivalents (50 mg of FPV = 43.2 mg of APV). Normalizing CL/F for bodyweight allows for comparison of CL/F across populations.

Apparent clearance of drug from plasma following extravascular administration (CL/F) was calculated as dose/AUC(0-τ). For FPV, doses were expressed in APV molar equivalents (50 mg of FPV = 43.2 mg of APV).

The time to reach the maximum concentration (Cmax) at steady state is defined as tmax.

The apparent terminal phase half-life (t1/2) is calculated as loge2/λz. The apparent terminal phase rate constant (λz) is the slope of the terminal portion of the logarithmically transformed concentration-time data as estimated by linear regression.

An AE is any untoward medical occurrence in a patient or clinical investigation subject, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

Blood samples of all participants were collected under fasting conditions for the evaluation of triglycerides, total cholesterol, HDL cholesterol, LDL cholesterol, and serum glucose. Clinical chemistry analyses were carried out using the observed analysis strategy. Change from Baseline in triglycerides, total cholesterol, HDL cholesterol, LDL cholesterol, and serum glucose was calculated as the value at Week 48 minus the value at Baseline.

Blood samples of all participants were collected for the evaluation of serum lipase. Clinical chemistry analyses were carried out using the observed analysis strategy. Change from Baseline in serum lipase was calculated as the value at Week 48 minus the value at Baseline.

Blood samples of the participants were collected for the evaluation of AST and ALT. Clinical chemistry analyses were carried out using the observed analysis strategy. Change from Baseline in AST and ALT was calculated as the value at Week 48 minus the value at Baseline.

A toxicity was considered TE if it was > than the Baseline grade, and if it was observed on/after the date of the first dose of study drug (SD), and on/before the date of the last dose of SD. Leucopenia is the decrease in the number of leucocytes (white blood cells [WBCs]); neutropenia is the decrease in the number of neutrophils (type of WBCs). Per the Division of AIDS Table for Grading the Severity of Adult and Pediatric AEs: Grade 3 is "severe"; Grade 4 is "potentially life-threatening." ULN, upper limit of normal; LDL, low-density lipoprotein; PC, platelet count.

Plasma samples were assayed for RTV concentrations using a validated assay. The GlaxoSmithKline (GSK) Department of Clinical Pharmacology Modeling and Simulation conducted pharmacokinetic (PK) analysis of the plasma RTV concentration-time data using a model-independent approach. As a measure of total drug exposure, the area under the plasma-concentration-versus-time curve over the dosing interval at steady-state (AUC[0-τ]), where τ is the length of the dosing interval, was calculated by the linear up/log down trapezoidal method.

The maximum concentration at steady state (Cmax) was measured.

The plasma concentration at the end of the dosing interval at steady-state (Cτ) was measured.

Apparent clearance of drug from plasma following extravascular administration (CL/F) was calculated using the formulation: RTV Dose in mg/kg units divided by AUC(0-τ). Normalizing CL/F for bodyweight allows for comparison of CL/F across populations.

Apparent clearance of drug from plasma following extravascular administration (CL/F) was calculated as dose/AUC(0-τ).

The time to reach the maximum concentration (Cmax) at steady state is defined as (tmax).

alf-life (t1/2) is calculated as loge2/λz. The apparent terminal phase rate constant (λz) is the slope of the terminal portion of the logarithmically transformed concentration-time data as estimated by linear regression.

The majority of the FPV data were below the quantification limit. Therefore, plasma FPV PK parameters were not estimated.

The majority of the FPV data were below the quantification limit. Therefore, plasma FPV PK parameters were not estimated.

The majority of the FPV data were below the quantification limit. Therefore, plasma FPV PK parameters were not estimated.

The majority of the FPV data were below the quantification limit. Therefore, plasma FPV PK parameters were not estimated.

The majority of the FPV data were below the quantification limit. Therefore, plasma FPV PK parameters were not estimated.

The majority of the FPV data were below the quantification limit. Therefore, plasma FPV PK parameters were not estimated.

Blood samples of participants were collected to measure plasma HIV-1 RNA concentrations. PI-exp = PI-experienced.Virologic success was defined as plasma HIV-1 RNA <400 copies/mL. Virologic failure: (1) HIV-1 RNA >=400 copies/mL, (2) change of background antiretroviral treatment (ART), (3) discontinued study due to lack of efficacy, (4) discontinued study with last HIV-1 >=400 copies/mL. No virologic data at Week 48 window: (a) discontinued study due to an adverse event or death, (b) discontinued study due to other reasons, (c) missing data during window but still on study.

Blood samples of participants were collected to measure plasma HIV-1 RNA concentrations. PI-exp = PI-experienced. Viral load, measured in RNA copies per milliliter of plasma, is an efficacy measure for antiretroviral drugs. In the Missing, Switch, or Discontinuation = Failure (MSD=F) analysis, participants who had missing data at or had discontinued the study prior to a certain time point or had changed their background antiretroviral regimen are classified as non-responders.

Blood samples of participants were collected to assess the decrease in the number of HIV-1 RNA.

Blood samples of participants were collected to assess the decrease in the number of HIV-1 RNA. Change from Baseline at Weeks 2, 12, 24, and 48 was calculated as value at Week 2, 12, 24, and 48 minus the value at Baseline.

Blood samples of participants were collected to assess the decrease in the number of HIV-1 RNA.

Blood samples of participants were collected for the measurement of CD4+ cell count. Observed analysis was used for the summary of proportion endpoints using viral load data. CD4+ cells are white blood cells that are important in fighting infection. HIV infects CD4+ cells, replicates in them, and destroys them. CD4+ cell count provides a measure of the status of the immune system and to what extent it is affected by HIV.

Blood samples of participants were collected for the measurement of CD4+ cell count. Observed analysis was used for the summary of proportion endpoints using viral load data. Change from Baseline was calculated as the value at Weeks 2, 12, 24, and 48 minus the value at Baseline.

Blood samples of participants were collected for the measurement of the percentage of total lymphocytes that are CD4+ cells. Observed analysis was used for the summary of proportion endpoints using viral load data.

Blood samples of participants were collected for the measurement of the percentage of total lymphocytes that are CD4+ cells. Observed analysis was used for the summary of proportion endpoints using viral load data. Change from Baseline in percentage was calculated as the value at Weeks 2, 12, 24, and 48 minus the value at Baseline.

A blood sample was drawn for par. failing to respond to therapy, and the mutations present in the virus were identified. For each par., the mutations found at the time of failure were compared with any mutations found in the blood sample at baseline. New International AIDS Society-USA defined resistance mutations that developed at the time of failure were tabulated by drug class. VF, virologic failure; NRTI, nucleoside reverse transcriptase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor. Par. are grouped by study arm and prior therapy experience.

A blood sample was drawn for par. remaining in the study after Week 48 and failing to respond to therapy, and the mutations present in the virus were identified. For each par., the mutations found at the time of failure were compared with any mutations found in the blood sample at baseline. New International AIDS Society-USA defined resistance mutations that developed at the time of failure were tabulated by drug class. VF, virologic failure; NRTI, nucleoside reverse transcriptase inhibitor; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor. Par. are grouped by study arm and prior therapy experience.

A blood sample was drawn for par. failing to respond to therapy, and changes in DS for HIV isolated from the par. for each drug used in the study were assessed. The changes in DS detected by phenotypic assay in virus from the sample collected at the time of failure was compared with DS in the virus from the blood sample at baseline. Par. are grouped by study arm and prior therapy experience. DS is the state of HIV being susceptible to the antiretroviral agent (the virus can be inhibited by the drug). Reduced DS (i.e., HIV is resistant to the antiretroviral agent) can lead to treatment failure.

A blood sample was drawn for par. remaining in the study after Week 48 and failing to respond to therapy, and changes in DS for HIV isolated from the par. for each drug used in the study were assessed. The changes in DS detected by phenotypic assay in virus from the sample collected at the time of failure was compared with DS in the virus from the blood sample at baseline. Par. are grouped by study arm and prior therapy experience. DS is the state of HIV being susceptible to the antiretroviral agent (the virus can be inhibited by the drug). Reduced DS (i.e., HIV is resistant to the antiretroviral agent) can lead to treatment failure.

The PACTG Adherence Questionnaire records individual study drugs, the expected number of doses/24 hour period, and the number of doses missed in the 3 days prior to the study visit. Responses were summarized by age cohort, study drug, treatment regimen, and visit for exploratory analysis only.

No formal analysis has been performed or is planned to correlate plasma APV PK with efficacy and safety outcomes.