Three-Year Outcomes After Genotyping-Guided Treatment Switch in HIV Patients with Virologic Failure in Cameroon: Implications for Epidemic Control in Low- and Middle-Income Countries

OBJECTIVES: Monitoring of HIV-infected patients with long-term treatment remains challenging in low- and middle-income countries (LMICs) due to risks of multi-class HIV drug resistance (HIVDR). We sought to evaluate the treatment response after a genotypic resistance-guided treatment switch among patients with multi-class HIVDR in Cameroon. METHODS: A retrospective cohort study was conducted in the South-West region of Cameroon among patients failing first- and second-line antiretroviral treatment (ART) (i.e., non-nucleoside reverse transcriptase inhibitors (NNRTI)- and protease inhibitor (PI)-based) from 2018-2023. Following HIV-1 genotypic resistance testing (GRT), patients were switched to the most effective genotype-guided therapies and viral load (VL) was monitored thereafter. Data analysis was performed using Epi-Info v.7.2, with p<0.05 considered significant. RESULTS: Overall, 81 patients were included in the study (median CD4 and VL were 232.5 [161.25-401.25] cells/µL and 54,480 [13,932.5-220,153] copies/mL, respectively). HIVDR at failure (i.e., VL>1000copies/mL) was 61.7%, and prevailing mutations were M184V (24.6%), K103N (17%) and M46I (32.1%) for NRTI, NNRTI and PI respectively. Monitoring data revealed 92.6% of adherence to the prescribed regimen. Viral suppression post-GRT was 80% at 3-months, 84.8% at 6-months, 81.4% at 12-months, 93.7% at 24-months and 86.9% at 36-months. Furthermore, DTG-based regimens yielded significantly higher responses than DTG-sparing regimens up to 24-months (p=0.013, p=0.0015, p=0.0005, p=0.02, respectively). CONCLUSIONS: Our findings highlight sustained viral suppression over three years following GRT-guided switch among individuals with multi-class HIVDR, mainly driven by DTG-based regimens. This underscores the significance of personalizing ART-management for difficult-to-treat people to achieve HIV control by 2030 in LMICs.