On December 22, the Food and Drug Administration approved Gilead Sciences’ Sunlenca (lenacapavir), a new option for treatment-experienced people with multidrug-resistant HIV who are unable to maintain viral suppression on their current regimen. The first approved HIV capsid inhibitor, Sunlenca disrupts the cone-shaped shell that surrounds the viral genetic material and essential enzymes. In the Phase II/III CAPELLA trial, 36 participants added either Sunlenca or placebo pills to their failing regimen for 14 days, and then everyone was offered Sunlenca injections every six months plus an optimized background regimen. After 52 weeks, 83% had an undetectable viral load, and CD4 counts increased by an average of 82 cells. Sunlenca is now the longest-acting HIV medication, but it can’t be used alone. Currently, no other antiretrovirals can be taken as infrequently as once every six months, so it is not yet possible to construct a complete twice-yearly regimen. Gilead is also testing Sunlenca for first-time HIV treatment and for pre-exposure prophylaxis (PrEP).