Drug-Drug Interactions Between Rifapentine and Dolutegravir in HIV/LTBI Co-Infected Individuals

The purpose of this study was to evaluate the potential drug-drug interactions between dolutegravir (DTG) and steady state rifapentine (RPT) when RPT was given with isoniazid (INH) daily for 4 weeks (1HP) as part of treatment for latent TB infection (LTBI) in HIV-1 and LTBI co-infected individuals.

Participants received study-provided INH and RPT once daily for 4 weeks (1HP). During the 1HP treatment, DTG was administered twice daily in Arm 1. Arm 2 planned to administer DTG once daily.

At study entry, all participants were required to be on DTG-based antiretroviral (ARV) treatment with 2 nucleoside reverse transcriptase inhibitors (NRTIs) (tenofovir alafenamide \[TAF\] was prohibited) during the study. In Arm 1, DTG 50 mg was administered twice daily; the morning dose from non-study ARV supply and the evening dose from study supply.

Participants were also required to receive pyridoxine (vitamin B6) with each dose of INH based on the current local, national, or international dosing guidelines. NRTI therapy and pyridoxine (vitamin B6) was not provided by the study.

The majority of Arm 1 participants were on study for 6 weeks (a 4-week on-study treatment period and a 2-week follow-up period). Arm 1 participants could be on study for up to 11 weeks if the on-study treatment duration was extended or if participants needed additional follow-up visits to measure viral load.

The study began enrollment with Arm 1. Opening of Arm 2 was dependent upon assessment of DTG pharmacokinetics (PK) data from participants in Arm 1.

Arm 1 is complete and results are reported. Arm 2 was not conducted based on the Arm 1 PK assessment.