Effectiveness of Dolutegravir in People on Rifampin-Based Tuberculosis Treatment

ABSTRACT

Background: Tenofovir-lamivudine-dolutegravir (TLD) is the WHO-preferred first-line regimen for people with HIV, but drug-drug interactions between dolutegravir (DTG) and rifampin (RIF) require an additional 50mg DTG (TLD+50) in people receiving tuberculosis (TB)/HIV co-treatment. RIF is a key drug in TB treatment, but is a potent inducer of metabolizing enzymes and efflux transporters, which can markedly lower drug concentrations. There are limited data on the effectiveness of TLD+50 in people with TB/HIV from program settings. Method(s) We conducted a prospective, observational study at 12 sites in 6 countries (Haiti, Kenya, Malawi, South Africa, Uganda, Zimbabwe). Participants received concomitant TLD+50 and RIF-based TB treatment provided as standard of care by HIV and TB treatment programs. Primary outcome was HIV-1 RNA <1000 copies/mL (cpm) at end of TB treatment. New DTG resistance mutations were defined as those present at end of TB treatment but not present at start. Result(s) From 11/2019-6/2021, we enrolled 91 participants with TB/HIV, including 75 ART-naive participants (82%) starting TLD+50 after a median of 15 days on TB treatment, 10 ART-naive participants (11%) starting TLD+50 and RIF together, 5 (5%) starting TB treatment and changing to TLD+50 after a median of 3.3y on TLD, and 1 (1%) starting RIF and TLD+50 after changing from EFV/3TC/TDF. Median age was 37y (IQR 32-43), 35% were female, 100% cis-gender, median CD4 count was 120 cells/mm3 (IQR 50-295), 87% had HIV-1 RNA >1000 copies/mL. Two participants died during TB treatment (week 4 disseminated TB, week 12 suspected COVID-19), 1 interrupted TLD+50 due to jaundice;and 1 discontinued TB treatment due to drug-induced liver injury. Among 89 surviving participants, 6 were lost to follow-up and a further 10 had no HIV-1 RNA result due to missed or remote visits. Primary virologic outcome was therefore assessed in 73 (80%), of whom 69 (95%, Wald 95% CI 89-100%) had HIV-1 RNA <=1000 cpm;68 (93%) had HIV-1 RNA <200 cpm. No sex specific differences in viral suppression were observed. No DTG resistance mutations were detected among 4 participants with HIV-1 RNA >1000 cpm. Conclusion(s) Concomitant RIF-containing TB treatment and TLD+50 was welltolerated and achieved excellent viral suppression in a cohort of predominantly ART-naive people with TB/HIV. These multi-country data from program settings support feasibility and effectiveness of current treatment approaches for TB/ HIV co-infection.