Characterizing CAR T cell products with optimal activity against HIV envelope trimer for a functional cure

Human Immunodeficiency Virus 1 (HIV-1) primarily infects CD4+ T cells leading to progressive immunodeficiency. Although antiretroviral therapy (ART) can durably suppress HIV replication, it is not curative and requires lifelong treatment. Chimeric antigen receptor (CAR) T cell therapy, specifically using broadly neutralizing antibody (bNAb)-derived ectodomains targeting conserved regions of the HIV Envelope (Env), offers a promising strategy to enhance immune control across diverse virus isolates. Here, through extensive in vitro characterization of distinct epitope classes of bNAb CARs, we identified that CARs targeting regions more distal from the plasma membrane exhibited superior effector functions, with the V3 glycan supersite targeting bNAb CARs displaying superlative potency. Moreover, we define mechanistic differences underlying this effect, highlighting CAR avidity as a predictor of intra- and inter-epitope potency hierarchies. In an in vivo humanized mouse model of HIV infection, a combination of bNAb-based CAR T cells targeting distinct epitopes and that individually select for orthogonal escape variants slowed viral escape kinetics and reduced plasma viremia. A multivalent CAR T cell product co-expressing three distinct bNAb-based CAR constructs demonstrated enhanced antigen sensitivity and achieved durable control of plasma viremia in a subset of HIV-infected humanized mice. These results highlight the therapeutic potential of multivalent bNAb-based CAR T cells and support their further development as a durable strategy for a functional HIV cure.