HIV
and Hepatitis.com Coverage of the 14th
Annual Conference on Retroviruses and Opportunistic Infections (14th CROI) February
25 - 28, 2007, Los Angeles, CA
Predictors
of Loss of Virological Control in Patients Receiving Lopinavir/ritonavir (Kaletra)
Monotherapy
Various approaches to treatment simplification have
been explored in an effort to improve the convenience and reduce the toxicity
associated with antiretroviral therapy, including monotherapy with boosted protease
inhibitors.
In Abbott Study M03-613, a majority of participants
received successful induction therapy with lopinavir/ritonavir
(Kaletra) plus AZT/3TC
(Combivir), followed by lopinavir/ritonavir monotherapy to maintain viral
suppression below 50 copies/mL for as long as 72 weeks.
However, compared
to study participants receiving efavirenz
(Sustiva) plus AZT/3TC, subjects receiving lopinavir/ritonavir monotherapy were more
likely to experience HIV
RNA rebound above 50 copies/mL.
Researchers at 5 medical centers sought to determine
the predictors of loss of virological response to lopinavir/ritonavir monotherapy
in this study, as reported at the 14th Conference
on Retroviruses and Opportunistic Infections last month in Los Angeles.
Of 104 subjects randomized
to receive lopinavir/ritonavir
plus AZT/3TC, 92 achieved 3 consecutive plasma viral loads below 50 copies/mL,
de-intensified to lopinavir/ritonavir
monotherapy, and were followed for a median of 68 weeks on monotherapy to determine
possible predictors of loss of response, including race, sex, baseline viral load,
baseline CD4 cell
count, and adherence.
Based on their analysis
of the data, the investigators concluded, “Adherence was associated with confirmed
virologic rebound on lopinavir/ritonavir
monotherapy. Baseline CD4 count may be a determinant in the success of an induction
maintenance strategy.”
Reference R Campo, B da Silva, L Cotte, and others.
Predictors of Loss of Virologic Response in Subjects Who Deintensified to
Lopinavir/Ritonavir Monotherapy after Achieving Plasma HIV-1 RNA < 50 Copies/mL
on LPV/r plus Zidovudine/Lamivudine. 14th Conference
on Retroviruses and Opportunistic Infections. Los Angeles, CA. February
25-28, 2007. Abstract 514 (poster).
