Atazanavir: in pediatric patients with HIV-1 infection.

Atazanavir is a selective and potent inhibitor of the HIV-1 protease. The drug is administered in combination with low-dose ritonavir, to boost atazanavir pharmacokinetics (i.e. ritonavir-boosted atazanavir), and other antiretroviral agents. The efficacy of once-daily ritonavir-boosted atazanavir plus background therapy (BT) in establishing virologic suppression in treatment-naive pediatric patients (aged 6 to <18 years) infected with HIV-1 was demonstrated in an ongoing, open-label, multicenter, phase I/II trial (PACTG 1020A). HIV-1 RNA levels of <50 or <400 copies/mL were achieved by the majority of patients (>70%) after 24 weeks' therapy, with these benefits maintained at week 48. Some treatment-experienced pediatric patients (aged 6 to <18 years) also achieved HIV-1 RNA levels of <50 or <400 copies/mL in the PACTG 1020A trial after 24 (≤45% of patients) and 48 (≤32%) weeks of treatment with ritonavir-boosted atazanavir plus BT, although the benefits of the regimen in this patient population appeared to be limited by as few as one or two protease inhibitor resistance mutations. Treatment-experienced pediatric patients (aged 10-19 years) infected with HIV-1 had mixed success in establishing/maintaining virologic suppression when they were switched from their current antiretroviral treatment regimen to once-daily ritonavir-boosted atazanavir plus BT in a small, single-center, observational study. However, some patients may have received atazanavir at a suboptimal dosage or had suboptimal susceptibility to BT agents. In the PACTG 1020A trial, use of atazanavir (with or without ritonavir) in pediatric patients aged 6 to <18 years was associated with a similar safety profile to that reported in adults.