A Phase IV-III Comparative, Randomized, Open-label Study to Evaluate the Efficacy for the Recovery of Peripheral Fat (or of the Extremities) of Lopinavir/Ritonavir in Monotherapy Versus Abacavir/Lamivudine and Lopinavir/Ritonavir

After more than ten years since it was started, it has already been established that highly-active antiretroviral treatment (HAART) has caused a dramatic reduction in the morbidity and mortality of human immunodeficiency virus (HIV) infection. However, HAART is not exempt of limitations, namely, its toxicity in the long-term; this is of special importance now that treatment of HIV is chronic.

Most common HAART involves the use of two nucleoside reverse transcriptase inhibitors (nucleoside or nucleotide analogues, NRTIs) and either a protease inhibitor (PI) or a non-analogue reverse transcriptase inhibitor (NNRTI). However, there are other regimens that remove some of these families, such as those based on three NRTIs, ZDV+3TC+ABC.

HAART has been associated with a constellation of major metabolic adverse events, such as fat redistribution (lipodystrophy, lipoatrophy, lipohypertrophy-central obesity - or both) and hyperlipidemia (hypercholesterolemia and hypertriglyceridemia).

Lipoatrophy, specifically, occurs as a loss of subcutaneous fat mass in the upper and lower extremities, with the possible appearance of venomegaly in face and buttocks Lipoatrophy is particularly distressing not only for itself, but for its stigma component, affecting the quality of life and the psychological condition of the patient.This also has a direct impact on treatment compliance, that is reduced, and, therefore, at risk that the therapeutic regimen fails to be effective for resistances selection.

Although initially most metabolic adverse events were attributed to PIs, in recent years it has been shown that lipoatrophy specifically is related more to therapy with NRTIs than with PIs; specifically, d4T, ddI and ZDV.