KONCERT A Kaletra ONCE Daily Randomised Trial of the Pharmacokinetics, Safety and Efficacy of Twice-daily Versus Once-daily Lopinavir/Ritonavir Tablets Dosed by Weight as Part of Combination Antiretroviral Therapy in Human Immunodeficiency Virus-1 (HIV-1) Infected Children (PENTA 18)

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 Ribonucleic acid (RNA) ≥50 copies/ml (confirmed).

Time frame: week 48

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

Time frame: Week 36

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

Time frame: week 24

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

Time frame: week 12

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

Time frame: week 8

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

To evaluate whether once-daily dosing of lopinavir/ritonavir is comparable to twice-daily dosing in terms of virological suppression. This is measured by HIV-1 RNA ≥50 copies/ml (confirmed).

Time frame: week 4

To compare the pharmacokinetics of twice-daily lopinavir/ritonavir tablets with once-daily dosing in the same children

Area under the curve (AUC), minimum observed plasma concentration (Cmin) and maximum observed plasma concentration (Cmax) values of lopinavir after once-daily and twice-daily dosing (in the same children)

Time frame: week 4