Pharmacokinetic Properties of Antiretroviral and Anti-Tuberculosis Drugs During Pregnancy and Postpartum

This study will evaluate the pharmacokinetic (PK) properties of antiretroviral (ARV) and anti-tuberculosis (TB) drugs administered during pregnancy and postpartum.

IMPAACT 2026 is a Phase IV observational clinical study. Participants are not assigned to the drugs under study, but are already receiving the drugs for clinical care by prescription of their clinical care providers. They are enrolled into study arms according to the drugs they are receiving through clinical care, and if on multiple drugs of interest, are able to enroll into multiple arms simultaneously. No ARVs or TB treatment drugs are supplied as part of this study. All drugs under study are provided by non-study sources. The study sponsor added this observational study to an existing investigational new drug (IND) number for off-label use in case the participant's clinical care provider decides to prescribe a higher dose than the approved dose if the PK results for the approved dose indicate that drug exposure may be inadequate.

This study is comprised of five components which in turn are comprised of arms specific to each drug or drug combination being evaluated:

* Component 1 (Arms 1.1, 1.2. 1.3. 1.4. and 1.5): Pregnant women living with HIV (WLHIV) receiving oral ARVs and no TB drugs, and their infants. * Component 2 (Arm 2.1): Pregnant WLHIV and HIV-uninfected women who received long-acting/extended release ARVs during pregnancy, and their infants. * Component 3 (Arms 3.1, 3.2, and 3.3): Pregnant WLHIV receiving ARVs and first-line TB treatment, and their infants. * Component 4 (Arm 4.1): Pregnant WLHIV and HIV-uninfected women receiving second-line TB treatment, and their infants. * Component 5 (Arms 5.1, 5.2. and 5.3): Postpartum WLHIV breastfeeding while receiving oral ARVs, and their infants.

Each arm will open to accrual independently and will accrue independently over approximately 36 months from the first enrollment in each arm.

Participants in Component 1 will be followed up to 12 weeks after delivery for mothers and up to 24 weeks after birth for infants. Participants in Component 2 will be followed up to 5 weeks after delivery for mothers and infants. Participants in Components 3, 4, and 5 will be followed up to 24 weeks after delivery for mothers and infants.

Study visits may include:

* Component 1: Maternal clinical and laboratory evaluations and PK sampling at second trimester (2T), third trimester (3T), delivery, and 6-12 weeks post-partum (PP). Infant clinical evaluations and washout PK sampling at birth and 5-9 days after birth. * Component 2: Maternal clinical and laboratory evaluations and PK sampling at delivery. Infant clinical evaluations and washout PK sampling at birth, 5-9 days, and 12-16 days after birth. Maternal and infant breast milk transfer PK sampling at 5-9 days, 12-16 days, and 3-5 weeks after delivery. * Component 3: Maternal clinical and laboratory evaluations and PK sampling at second trimester (2T), third trimester (3T), delivery, and 2-8 weeks post-partum (PP). Infant clinical evaluations and washout PK sampling at birth and 5-9 days after birth. Maternal and infant breast milk transfer PK sampling at 5-9 days, 2-8 weeks, and 16-24 weeks after delivery. * Component 4: Maternal clinical and laboratory evaluations and PK sampling at second trimester (2T), third trimester (3T), delivery, and 2-8 weeks post-partum (PP). Infant clinical evaluations and washout PK sampling at birth and 5-9 days after birth. Maternal and infant breast milk transfer PK sampling at 5-9 days, 2-8 weeks, and 16-24 weeks after delivery. * Component 5: Maternal and infant clinical evaluations and breast milk transfer PK sampling at 5-9 days, 2-12 weeks, and 16-24 weeks after delivery.