Emtricitabine and tenofovir alafenamide vs emtricitabine and tenofovir disoproxil fumarate for HIV pre-exposure prophylaxis (DISCOVER): primary results from a randomised, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial

This study (DISCOVERY; n=5,857) found emtricitabine and tenofovir alafenamide was non-inferior to emtricitabine and tenofovir disoproxil fumarate for HIV prevention (incidence rate ratio 0.47; 95% CI 0.19-1.15 [upper limit below prespecified non-inferiority margin of 1.62]).

SPS commentary:

The number of adverse events (AE) for both regimens was low, with discontinuation due to AE in 1% of the emtricitabine and tenofovir alafenamide group vs 2% of the emtricitabine and tenofovir disoproxil fumarate group. Emtricitabine and tenofovir alafenamide had more favourable effects on bone mineral density and biomarkers of renal safety.

A related commentary notes that the DISCOVERY trial is limited by its restricted eligibility (excluded cisgender women, people who inject drugs and adolescents); in addition participation of transgender women was low and only 9% were Black or mixed Black race. The US FDA approved emtricitabine/ tenofovir alafenamide for pre-exposure prophylaxis on the basis of the primary efficacy data from this study, but only for use in men and transgender women who have sex with men. It is not yet approved in the EU/UK for this indication. A study evaluating this regimen for pre-exposure prophylaxis in cisgender women and adolescent girls is planned and expected to complete as early as 2024.


The Lancet

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