Delineating Structural Functionalities of Lenacapavir Amenable to Modifications for Targeting Emerging Drug-Resistant HIV-1 Capsid Variants

Lenacapavir (LEN) is a new, first-in-class, long acting, HIV-1 capsid (CA)-targeting inhibitor for treating multidrug-resistant HIV-1 infections. LEN exhibits high potency against all major HIV-1 subtypes including variants resistant to current antiretroviral therapies providing a life-saving opportunity for heavily treatment-experienced adults with multidrug-resistant HIV-1. Despite this, LEN has a relatively low barrier to viral resistance. Clinical trials identified resistance-associated mutations near LEN binding site, with the M66I variant exhibiting highest level of resistance (>3200-fold). These findings necessitate continuing efforts to develop next-generation inhibitors against emerging LEN-resistant mutation. We focused on identifying LEN structural functionalities amenable to modifications and to develop LEN analogs with improved antiviral activity against the M66I mutant. Here, we report a new LEN analog, KFA-027, with substantially improved antiviral activity (EC₅₀ ∼ 444 nM, >20-fold) against M66I variant. Overall, these findings suggest a route for developing next-generation LEN analogs against WT and emerging drug-resistant CA mutations.