Monoclonal Antibody to Detect the Antiretroviral Drug Emtricitabine – for HIV Drug Adherence Monitoring

The U.S. Food and Drug Administration and World Health Organization (WHO) approved the antiretroviral drug emtricitabine (FTC)/ tenofovir disoproxil fumurate (TDF) combination for HIV pre-exposure prophylaxis (PrEP) in high risk populations. Efficacy of PrEP depends strongly on adherence to taking the FTC/TDF pill daily. In the US, the Centers for Disease Control and Prevention (CDC) estimates that 1.2 million Americans will benefit from PrEP. FTC is also a key component of antiretroviral therapy (ART) regimens of HIV-infected persons and significantly associated with adherence. According to reports from the WHO, 21.7 million HIV-infected persons worldwide were receiving ART by the end of 2017. Currently, laboratories use costly, complex, and time- consuming mass-spectrometry blood tests to monitor compliance in patients receiving PrEP and ART treatment.

CDC recently developed a monoclonal antibody (mAb) that specifically reacts with FTC. An enzyme immunoassay (EIA) test developed from the mAb could potentially maximize efficacy in PrEP users. The competitive EIA has clinically relevant sensitivity and specificity to FTC in urine. The mAb is also able to detect FTC in a lateral flow assay. These FTC assays may also aid ART management in HIV-infected persons to optimize treatment efficacy and maximize viral suppression.