UNIVERSAL 1: Pharmacokinetic Study of a Novel DTG/FTC/TAF Dose Ratio for Children

Dolutegravir (DTG), Emtricitabine (FTC) and Tenofovir alafenamide (TAF) are anti-HIV medicines. DTG works very well, can be taken once-daily and has few side effects. In international treatment guidelines, DTG is one of the most recommended medicines for adults and young people. Emtricitabine is also one of the preferred medicines in anti-HIV treatment for adults and children. Tenofovir alafenamide (TAF) is not yet recommended in children <25 kg, however TAF could potentially be used safely and effectively in children.

Combining DTG, FTC and TAF in a specific dose ratio may offer treatment that is safe and effective. If so, a combination dispersible tablet containing these three medicines can be developed and this will allow the same HIV medicines to be used across children and adults.

This study will include 50 children aged 28 days to less than 10 years old who are living with HIV. All participants will receive the same treatment with DTG, FTC and TAF. Subjects will receive DTG 10 mg dispersible tablets and FTC/TAF 15/1.88 mg dispersible tablets or DTG 50 mg film coated tablets and FTC/TAF 200/25 mg film coated tablets depending on weight band. All children in the study will have clinical assessments. Blood tests will be performed to make sure that the medicines are safe and, at some visits, participants and carers will also be asked to answer some questions on taking medicine and how medicine tastes. All children will be followed up for 24 weeks.

• dolutegravir (DTG)/emtricitabine (FTC)/tenofovir alafenamide (TAF) regimen (Drug): Switch or start dolutegravir (DTG)/emtricitabine (FTC)/tenofovir alafenamide (TAF) regimen with a novel dose ratio for HIV treatment
• Dolutegravir (DTG)/ Emtricitabine (FTC)/tenofovir alafenamide (TAF) (Drug): Single arm

Primary outcomes

• Primary endpoints for DTG: [From enrollment to the end of treatment at 24 weeks]: \- Geometric mean Ctrough concentration
• Primary endpoints for DTG: [From enrollment to the end of treatment at 24 weeks]: Percentage of individual Ctrough concentrations below the 90% effective concentration (EC90) (0.32 mg/L)
• Primary endpoints for DTG: [From enrollment to the end of treatment at 24 weeks]: \- Geometric mean DTG Ctrough, Cmax, and AUC
• Primary safety endpoints [From enrollment to the end of treatment at 24 weeks]: \- Occurrence of serious adverse events
• Primary safety endpoints [From enrollment to the end of treatment at 24 weeks]: \- Occurrence of new clinical and laboratory grade 3 and 4 adverse events
• Primary safety endpoints [From enrollment to the end of treatment at 24 weeks]: Occurrence of adverse events (of any grade) leading to treatment modification
• Primary endpoints for FTC/TAF: [From enrollment to the end of treatment at 24 weeks]: \- Geometric mean Ctrough, Cmax, and AUC
• Primary endpoints for FTC/TAF: [From enrollment to the end of treatment at 24 weeks]: Intracellular tenofovir diphosphate (TDP) levels at 24 hours acquired through dried blood spot analysis

Secondary outcomes

• Efficacy endpoints [From enrollment to the end of treatment at 24 weeks]: \- Viral load (VL) <400 c/ml at 24 weeks
• Efficacy endpoints [From enrollment to the end of treatment at 24 weeks]: Occurrence of new or recurrent WHO clinical stage 3 or 4 event

Sex: All, ages: 28 Days to 10 Years

Inclusion Criteria:

* Age between 28 days and 10 years old
* Weighing 3 to <25 kg
* Confirmed HIV-1 infection (local, molecular methods)
* A parent or legal guardian is willing and able to give informed consent on behalf of the child as per national legislation and willing to adhere to the protocol
* Participant is willing to give informed assent if the trial site clinician deems them old enough and able to understand the age-appropriate information about participation in the study
* Girls who have reached menarche must have a negative pregnancy test at screening
* Subject is willing to start DTG/FTC/TAF regimen in the novel dose ratio for HIV treatment
* Subjects already on a DTG-based ART regimen should be virologically suppressed at screening

Exclusion Criteria:

* Age between 28 days and 10 years old
* Weighing 3 to <25 kg
* Confirmed HIV-1 infection (local, molecular methods)
* A parent or legal guardian is willing and able to give informed consent on behalf of the child as per national legislation and willing to adhere to the protocol
* Participant is willing to give informed assent if the trial site clinician deems them old enough and able to understand the age-appropriate information about participation in the study
* Girls who have reached menarche must have a negative pregnancy test at screening
* Subject is willing to start DTG/FTC/TAF regimen in the novel dose ratio for HIV treatment
* Subjects already on a DTG-based ART regimen should be virologically suppressed at screening
* History or presence of known allergy to DTG, FTC or TAF
* Alanine aminotransferase (ALT) ≥5 times the upper limit of normal (ULN), OR ALT ≥3xULN AND bilirubin ≥2xULN
* Patients with severe hepatic impairment or unstable liver disease (as defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminaemia, oesophageal or gastric varices, or persistent jaundice), known biliary abnormalities (with the exception of Gilbert's syndrome or asymptomatic gallstones)
* Current or anticipated need for TB therapy during the study
* Use of rifampicin-based therapy within 4 weeks before start trial
* Presence of comedication known to interact with trial medications
* Known resistance to INSTI or NRTI

• Results publication: Kamphuis AEM, Salvadori N, Mujuru HA, Bwakura-Dangarembizi M, Kisitu GP, Matovu F, Kaudha E, Mulindwa A, Jacobs TG, Than-In-At K, Cressey TR, Nardone A, Lallemant M, Colbers A, Burger DM; UNIVERSAL1 trial team. Expediting a UNIVERSAL first-line regimen of a dolutegravir-emtricitabine-tenofovir alafenamide fixed-dose ratio for children living with HIV older than 4 weeks: a 24-week, open-label, single-arm, phase 1-2, pharmacokinetic, safety, and antiviral activity trial. Lancet HIV. 2026 Sep 7:S2352-3018(26)00168-2. doi: 10.1016/S2352-3018(26)00168-2. Online ahead of print. PMID 42705257