558. Genotype-Guided vs. Standard First-line Antiretroviral Regimen for Treatment Naïve HIV-Infected Patients in Thailand: A Prospective Randomized Controlled Trial

BACKGROUND: An increase in the prevalence of pretreatment drug resistance (PDR) has been reported among HIV-infected individuals and PDR may be associated with poor treatment outcome of first-line antiretroviral therapy (ART). However, drug resistance testing prior to ART initiation is not routinely performed in resource-limited settings. We aimed to evaluate the prevalence of PDR in Thailand and whether genotype-guided first-line ART can improve treatment outcomes. METHODS: A prospective, multicenter, randomized, controlled trial was conducted involving newly diagnosed HIV-infected adults. Participants who were going to initiate ART were randomly assigned to either genotype-guided (GG) group or standard of care (SC) group with 1:1 allocation as per a computer-generated randomization. Genotypic resistance assay was performed in all participants. The investigators in GG group were informed the results of genotypic resistance assays before selecting the ART regimen. In contrast, the results of SC group were blinded to the investigators. Factors associated with having PDR and undetectable HIV RNA were analyzed by logistic regression. RESULTS: A total of 153 participants were randomized to either GG group (78 participants) SC group (75 participants). Of all, median (IQR) age was 32 (26–42) years and 83% were male. Median (IQR) CD4 count was 190 (42–324) cells/mm(3). Overall prevalence of PDR was 13.7% and NNRTIs PDR was 10.5%. The most common mutation was V179D (5.9%), T215Y (3.9%) and E138K (2.0%). No associated factor of having PDR was determined. At 24 weeks, 85.9% in GG group and 86.3% in SC group had undetectable HIV RNA (P = 0.940). By univariate logistic regression, having PDR was not associated with undetectable HIV RNA (OR 0.40; 95% CI 0.12–1.30, P = 0.122). By multiple logistic regression, factors associated with undetectable HIV RNA were adherence (OR 1.53 per 5% increment; 95% CI 1.15–2.05; P = 0.004) and no history of PJP (OR 6.24; 95% CI 1.62–24.08; P = 0.008). CONCLUSION: In Thailand, the prevalence of PDR is moderate and NNRTIs PDR is high according to the WHO category. Recommended first-line ART for Thai HIV-infected patients should be modified. Routine genotype-guided first-line ART is not now recommended in Thailand. Periodically PDR surveillance and cost-effectiveness study of genotype-guided first-line ART should be further studied. [Image: see text] DISCLOSURES: All authors: No reported disclosures.