A Study to Assess the Acceptability of the Darunavir/Cobicistat (DRV/COBI) Fixed-dose Combination (FDC) Tablet in Human Immunodeficiency Virus (HIV)-1 Infected Children

The purpose of the study is to assess the ability to swallow the Darunavir/Cobicistat (DRV/COBI) fixed dosed combination (FDC) tablet dispersed in water.

Human immunodeficiency virus type 1 (HIV-1) infection is a life-threatening and serious disease that is of major public health interest around the world. Standard-of-care for the treatment of HIV infection involves the use of a combination of antiretroviral (ARV) drugs to suppress viral replication to below detectable limits, to increase CD4+ cell count, and to delay disease progression. Darunavir (DRV) is an inhibitor of the dimerization and of the catalytic activity of the HIV-1 protease. It selectively inhibits the cleavage of HIV encoded Gag-Pol polyproteins in virus infected cells, thereby preventing the formation of mature infectious virus particles. Cobicistat (COBI) is a mechanism-based inhibitor (MBI) of the cytochrome P450 (CYP)3A subfamily. Inhibition of CYP3A mediated metabolism by COBI enhances the systemic exposure of CYP3A substrates, such as DRV, where bioavailability is limited and half-life is shortened by CYP3A-dependent metabolism. DRV/COBI FDC tablet formulation would overcome the difficulties of pediatric participants (greater than or equal to \[\>=\] 3 years and weighing \>=15 kilograms \[kg\] to less than \[\<\] 25 kg) might encounter in swallowing a whole or 2 halves of an oral, non-disintegrating tablet, hence helping children to better adhere to their HIV treatment. The study consists of a screening phase (up to 21 days) and an open-label administration phase of 1 day. Safety will be assessed by adverse events (AEs). The total duration of the study is up to 32 days.

Eligibility Criteria:
Inclusion Criteria

* Has documented chronic Human Immunodeficiency Virus (HIV-1) infection
* Must be on an allowed stable unchanged antiretroviral (ARV) regimen for at least 3 months prior to screening
* Has a documented plasma HIV-1 Ribonucleic acid (RNA) less than 400 copies/milliliters (mL) within 6 months prior to or at screening
* Must be in a condition that allows to perform the protocol-specified assessments and so must his/her caregiver, if applicable. If a participant and his or her caregiver have difficulties in completing the questionnaire, the study-site personnel may assist
* Body weight within greater than or equal to (\>=) 15 kilograms (kg) to less than (\<) 25 kg

Exclusion criteria

* Known allergies, hypersensitivity, or intolerance to Darunavir/Cobicistat (DRV/COBI) or any excipient of the study intervention
* Has taken any disallowed therapies
* Any active condition (example, active oral infection \[candidiasis\], significant physical or psychological disease or other findings during screening) that could prevent the participant from swallowing dispersions in water, or for which, in the opinion of the investigator, participation would not be in the best interest of the participant (example, compromise the well-being) or that could prevent, limit, or confound the protocol specified assessments and outcomes
* Active acquired immunodeficiency syndrome (AIDS)-defining illness at screening
* Has had any contact with severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) positive or Coronavirus Disease 2019 (COVID-19) participants within the last 2 weeks prior to admission to the clinical research center