Viral suppression among adults with HIV receiving routine dolutegravir-based antiretroviral therapy and 3 months weekly isoniazid-rifapentine.

Objective: We aimed to evaluate safety of 3 months weekly isoniazid-rifapentine (3HP) for tuberculosis (TB) prevention when co-administered with dolutegravir-based antiretroviral therapy (TLD), and compare viral suppression among those initiating TLD + 3HP vs. TLD alone.

Design/methods: We analyzed data from an ongoing Phase 3 randomized trial comparing TB screening strategies among adults with CD4 + ≤350 cells/μl initiating routine antiretroviral therapy (ART) in Kampala, Uganda. TB screen-negative participants without contraindications are referred for self-administered 3HP. HIV viral load is routinely measured at 6 and 12 months. Here, we included TB-negative participants who initiated TLD with or without 3HP. We determined the number who discontinued 3HP due to drug toxicity. In addition, we assessed viral suppression at 6 and 12 months and used log-binomial regression to assess risk of viremia at 6 months for participants who initiated TLD + 3HP vs. TLD alone.

Results: Of 453 participants initiating TLD (287 [63.4%] female, median age 30 years [interquartile range (IQR) 25-37], median pre-ART CD4 + cell count 188 cells/μl [IQR 86-271]), 163 (36.0%) initiated 3HP. Of these, 154 (94.5%) completed 3HP and one (0.6%) had treatment permanently discontinued due to a possible 3HP-related adverse event. At 6 months, for participants who received TLD + 3HP, risk of viremia >50 copies/ml was 1.51 [95% confidence interval (CI) 1.07-2.14] times that of participants who received TLD alone. There was no difference in viral suppression between those who received TLD + 3HP vs. TLD alone at 12 months.

Conclusions: Co-administration of TLD + 3HP was well tolerated. However, those who received TLD + 3HP were less likely to achieve viral suppression within six-months compared to those who received TLD alone.