Safety, adherence, and resistance were evaluated in a single-arm, open-label clinical trial (ATN113) in which 67 HIV-1 uninfected at-risk adolescent men who have sex with men received Truvada once daily for HIV-1 PrEP. The mean age of subjects was 17 years (range, 15-18 years); 46% were Hispanic, 52% black, and 37% white. The safety profile of Truvada in ATN113 was similar to that observed in the adult HIV-1 PrEP trials.
In the ATN113 trial, HIV-1 seroconversion occurred in three subjects. Tenofovir diphosphate levels in dried blood spot assays indicate that these subjects had poor adherence. No tenofovir- or FTC-associated HIV-1 resistance substitutions were detected in virus isolated from the three subjects who seroconverted.
Adherence to study drug, as demonstrated by tenofovir diphosphate levels in dried blood spot assays, declined markedly after Week 12 once subjects switched from monthly to quarterly visits, suggesting that adolescents may benefit from more frequent visits and counseling.
12.0 Clinical pharmacology
HIV-1 PrEP
The pharmacokinetic data for tenofovir and FTC following administration of Truvada in HIV-1 uninfected adolescents weighing 35 kg and above are not available. The dosage recommendations of Truvada for HIV-1 PrEP in this population are based on safety and adherence data from the ATN113 trial [see Use in Specific Populations (8.4)] and known pharmacokinetic information in HIV-infected adolescents taking TDF and FTC for treatment.