New HIV prevention breakthrough

Globally, women account for nearly half of all HIV infections, yet they remain under-represented among those using pre-exposure prophylaxis (PrEP). A recent study published in The New England Journal of Medicine, PURPOSE-1, sheds light on a promising new approach to HIV prevention: twice-yearly lenacapavir.

In this manufacturer-sponsored study, nearly 5,340 sexually active cisgender women in sub-Saharan Africa were divided into three groups: one received lenacapavir injections every six months, while the others took daily oral PrEP medications—FTC-tenofovir alafenamide (FTC/TAF) or FTC-tenofovir disoproxil fumarate (FTC/TDF).

The results are striking. The incidence of HIV among those receiving lenacapavir was zero, in stark contrast to the background rate of 2.41 per 100 person-years and the rates in the FTC/TAF (2.0) and FTC/TDF (1.7) groups. Adherence to oral PrEP was notably low, as many who contracted HIV were not using these daily medications.

Individuals who acquire HIV while on long-acting cabotegravir may exhibit a delayed immune response and low viral loads—a phenomenon known as long-acting early viral inhibition (LEVI). Some of these individuals develop resistance to cabotegravir.

The impressive results of lenacapavir could signal a new era in HIV prevention. If it proves effective in other populations, it may soon be approved by the U.S. FDA for PrEP. With broad and affordable access, this breakthrough could be pivotal in ending the HIV epidemic.