Efficacy and safety of a once-daily single-tablet regimen of tenofovir, lamivudine, and efavirenz assessed at 144 weeks among antiretroviral-naïve and experienced HIV-1-infected Thai adults.

Objective: To assess the efficacy and safety of a new single-tablet regimen (STR) of tenofovir disoproxil fumarate (TDF) 300mg, lamivudine (3TC) 300mg, and efavirenz (EFV) 600mg in HIV-infected Thai patients.

Methods: This was a prospective study performed for 144 weeks among 51 treatment-naïve patients and 49 experienced patients on separate tablets of TDF, 3TC, and EFV with HIV RNA<50 copies/ml. CD4, HIV RNA, liver and renal function, and lipid profiles were assessed at baseline, weeks 12, 24, and 48, and then every 24 weeks.

Results: The median baseline CD4 cell count was 512 cells/μl for treatment-experienced patients and 230 cells/μl for treatment-naïve patients. Median baseline log HIV-1 RNA for treatment-naïve subjects was 4.9 copies/ml. From the intention-to-treat (ITT) analysis, the proportion of subjects with HIV RNA <50 copies/ml at week 48, 96, and 144 was 95%, 94%, and 94%, respectively, for antiretroviral-experienced patients and 88%, 90%, and 80%, respectively, for antiretroviral-naïve patients. One virological failure at week 12 had primary drug resistance of K70R, T69D, V75L. Three serious adverse events occurred (tension headache, infective endocarditis, and cervical dysplasia) and another three discontinued the study drug due to EFV intolerance.

Conclusions: This generic STR TDF/3TC/EFV is effective and well-tolerated. These findings lend support to the use of this generic STR as first-line antiretroviral therapy in resource-limited settings.