Vamshi Jogiraju and colleagues at Gilead Sciences reported success in a phase I clinical trial of lenacapavir as a single-year injection of pre-exposure prophylaxis for HIV infection. As reported in The Lancet, the new formulation of this viral capsid inhibitor provided even more stable plasma concentrations than the twice-yearly formulation. It is lenacapavir free acid in 5- or 10-percent ethanol and is administered at a dose of 5,000 milligrams at a time as two intramuscular ventrogluteal injections. The previous injection form is administered subcutaneously every six months.
In a trial involving 32 adults, one year after a single intramuscular injection, the median plasma concentration of the drug was 57.0–65.6 nanograms per milliliter, while after six months with the subcutaneous administration of the previous form, it was 23.4 nanograms per milliliter. The most common side effect was pain at the injection site, which went away within a week. Lenacapavir injections twice a year have already demonstrated effective pre-exposure prophylaxis for HIV infection in phase III clinical trials and became the main breakthrough of 2024 according to the journal Science.