NIAID-led IMPAACT 2026 pharmacokinetic study terminated early, results posted

This week's update covers one study, "Pharmacokinetic Properties of Antiretroviral and Anti-Tuberculosis Drugs During Pregnancy and Postpartum" (NCT04518228, IMPAACT 2026), sponsored by NIAID with Gilead Sciences, ViiV Healthcare, and Merck Sharp & Dohme as collaborators.

• The trial, described as a Phase IV observational clinical study¹, was marked terminated. The sponsor said accrual was closed early after a Study Monitoring Committee review found that the objectives for the then-open arms had either been met or could not be achieved within a reasonable timeframe.¹
• Results were first posted on 2026-08-26, with primary completion recorded as 2025-04-24 and study completion as 2025-07-10.¹
• The study enrolled pregnant and postpartum women living with HIV, and some HIV-uninfected women, across five components covering oral antiretrovirals, long-acting antiretrovirals, and first- or second-line TB treatment, along with their infants, using a design in which participants were not assigned to drugs but were already receiving them for clinical care¹.
• The long-acting antiretroviral arm (Component 2, Arm 2.1) was never opened, because the sponsor decided that plans to study the pharmacokinetics and safety of long-acting injectable cabotegravir during pregnancy would instead be handled in a separate trial¹.
• Two oral antiretroviral arms, 1.1 and 1.4, hit their enrollment goals and were closed on that basis, while arms 1.3 and 5.1 were closed by the Core Protocol Team after enrollment slowed enough that the team judged existing participant numbers sufficient to move to data analysis and publication.¹