Effectiveness of a tenofovir/lamivudine/dolutegravir (TLD)-based regimen among people with HIV-1 attending the Bamenda Regional Hospital Treatment Centre, Cameroon: a retrospective observational study

Improving current and future antiretroviral treatment is crucial to ending AIDS by 2030. Treatment failure, drug toxicity and resistance remain major obstacles to durable viral suppression. In 2019, the World Health Organization (WHO) recommended a dolutegravir-based regimen (DTG) as preferred first- and second-line antiretroviral therapy to help address these challenges. However, data on its effectiveness among people with HIV-1 (PLHIV) receiving routine care remain scarce, particularly in Central Africa. This study evaluated virologic suppression among a cohort of adherent, comorbidity-free PLHIV receiving DTG at a regional treatment centre in Cameroon. This retrospective observational study reviewed the medical records of PLHIV aged above 18 years attending the Bamenda Regional Hospital HIV Treatment Centre, who had an adherence rate of at least 95% by pill count, had no recorded comorbidities, and were receiving dolutegravir as part of combination antiretroviral therapy (cART); 99.4% of participants were specifically on tenofovir/lamivudine/dolutegravir (TLD) and 0.6% on abacavir/lamivudine/dolutegravir. Both ART-naïve patients started on DTG-based first-line therapy and ART-experienced patients switched to a DTG-based regimen following the 2019 WHO recommendation were eligible. Eligible patients had initiated DTG-based cART between January 2020 and May 2021, early enough to have completed at least 12 months of follow-up before the close of the data-collection period in May 2022. The primary outcome was virologic suppression (< 1000 copies/mL) at 6 and 12 months, and the secondary outcome was 12-month DTG discontinuation due to a clinical switch to a non-DTG regimen. Because suppression was high (> 90%) with very few unsuppressed participants (7 at 6 months, 1 at 12 months), associations at 6 months were analyzed using crude risk ratios and Fisher’s exact tests. Multivariable adjustment was not possible, leaving the 6-month comparative analyses underpowered for small effect sizes, while formal 12-month statistical testing was omitted. Of 368 records screened, 157 participants met the eligibility criteria (105 treatment-naïve, 52 treatment-experienced) and had viral load data available at both 6 and 12 months. At 6 months, 150/157 participants (95.5%) were virologically suppressed; 7/157 (4.5%) were not. At 12 months, 156/157 participants (99.4%) were suppressed; 1/157 (0.6%) was not, and this participant was switched to a second-line regimen after confirmed virologic failure. No baseline factor examined sex, age, marital status, education, smoking, WHO clinical stage, treatment status, or HIV duration was significantly associated with 6-month suppression; given only 7 events, these null findings reflect limited statistical power rather than confirmed absence of association. Alcohol use at baseline was associated with a higher rate of 6-month suppression (risk ratio 1.14, 95% CI 1.02–1.28; Fisher’s exact p = 0.002); given the wide confidence interval, the small number of events, and the absence of adjustment for confounding, this finding should be treated as hypothesis-generating rather than confirmatory. By 12 months (week 48), the median weight change in the study population was + 2.0 kg (interquartile range [IQR] 0 to 4). In this adherent, comorbidity-free sub-population receiving routine HIV care in Cameroon, DTG-based cART was associated with high rates of virologic suppression at both 6 months (week 24) and 12 months (week 48), in both treatment-naïve and treatment-experienced participants. Because of the selective eligibility criteria, small sample, single-centre design and short follow-up, these findings should not be generalised to the broader population in routine HIV care, and do not by themselves establish comparative or causal effectiveness relative to other regimens; they add descriptive, real-world observations to the existing trial-based evidence for DTG-based regimens in a Central African setting.