Integrating dolutegravir into the national Tanzanian formulary: treatment uptake and virologic outcomes from a longitudinal study.

introductionThe transition to dolutegravir (DTG) antiretroviral therapy (ART) has now become the preferred first-line treatment for people living with HIV (PLHIV) in many low- and middle-income countries. We report virologic outcomes among adolescents and adults who transitioned to DTG-based therapy and those initiated on DTG based ART in Dar es Salaam, Tanzania.

methodsWe performed retrospective and prospective data abstraction from an electronic care and treatment database at Muhimbili National Hospital (MNH) for participants aged 15 years and above. Eligible participants were treatment-naïve PLHIV initiating tenofovir-lamivudine-efavirenz (TLE) or tenofovir-lamivudine-dolutegravir (TLD) and treatment-experienced patients with a transition opportunity between March 2019 and August 2019. We assessed baseline differences in patient characteristics before and after weighting with inverse probability weights using the chi-square and Mann-Whitney tests for categorical and continuous variables, respectively. A multivariate robust Poisson regression model was used to evaluate the probability of viral suppression (VS) for participants who transitioned to TLD. Differences in VS rate at follow-up between participants initiating TLE and TLD were assessed using the log-rank test and Kaplan-Meier survival curves.

resultsA total of 1,073 participants were included, 284 were initiated on ART, and 789 with a transition opportunity, with a median age of 39 years (IQR 33, 46), and 905 females (83.9%). Participants who transitioned their ART regimen to TLD had a higher rate of achieving VS compared to those who remained on TLE (92.4% versus 84.4%, respectively; p = 0.005). Notably, participants who remained on TLE had a higher proportion of high viral load (VL ≥ 1000 copies/ml), 15.6%, compared to 7.6% of those who transitioned to TLD. In multivariable analysis, participants who were initiated on TLD as their first line ART had 3-fold higher likelihood of VS compared to those new to TLE (adjusted hazard ratio 3.07, 95% CI 1.88-5.03 (p-value < 0.001). Other factors were not significantly associated with VS.

conclusionVS was higher in participants who transitioned to TLD and those initiated on TLD. Long-term follow-up of treatment-experienced, Integrase inhibitors (INSTI)-naïve and PLHIV who transitioned to the TLD regimen (with unknown viral loads or NRTI resistance) is recommended.