Pharmacokinetics of Once Daily Darunavir/Ritonavir in HIV-infected Children (DAPHNE)

Inclusion Criteria:

1. Parents/carers are able and willing to sign the informed consent form prior to screening evaluations
2. Subject is HIV infected
3. Subject is at least 6 and less than 12 years at day of screening
4. Subject has a body weight of at least 15kg
5. Subject is able to swallow tablets
6. Subject has an undetectable viral load (<50 copies/mL) for the last 6 months prior to screening (at least 2 measurements)
7. ART regimen consists of darunavir/ritonavir and 2 NRTIs

Exclusion Criteria:

1. Inability to understand the nature and extent of the trial and the procedures required
2. Documented history of sensitivity/idiosyncrasy to darunavir or ritonavir medicinal products or its excipients
3. Relevant history or current condition that might interfere with drug absorption, distribution, metabolism or excretion
4. Abnormal renal or liver function (grade 3 or above)
5. Participation in a drug trial within 60 days prior to the first dose
6. Hemoglobin < 10 g/dL (6.0 mmol/L)
7. Children who have previously failed virologically on a PI containing regimen (where virological failure is defined as two successive HIV-1 RNA results >1,000 c/mL more than 24 weeks after starting cART, i.e. changes for toxicity or convenience are not counted as failure)
8. Acute illness
9. Receiving concomitant therapy except for prophylaxis for opportunistic infections; some treatments may be allowed, but must first be discussed with the principal investigator or project manager.