Combination anti-HIV antibodies provide sustained virological suppression.

Antiretroviral therapy is highly effective in suppressing human immunodeficiency virus (HIV)1. However, eradication of the virus in individuals with HIV has not been possible to date2. Given that HIV suppression requires life-long antiretroviral therapy, predominantly on a daily basis, there is a need to develop clinically effective alternatives that use long-acting antiviral agents to inhibit viral replication3. Here we report the results of a two-component clinical trial involving the passive transfer of two HIV-specific broadly neutralizing monoclonal antibodies, 3BNC117 and 10-1074. The first component was a randomized, double-blind, placebo-controlled trial that enrolled participants who initiated antiretroviral therapy during the acute/early phase of HIV infection. The second component was an open-label single-arm trial that enrolled individuals with viraemic control who were naive to antiretroviral therapy. Up to 8 infusions of 3BNC117 and 10-1074, administered over a period of 24 weeks, were well tolerated without any serious adverse events related to the infusions. Compared with the placebo, the combination broadly neutralizing monoclonal antibodies maintained complete suppression of plasma viraemia (for up to 43 weeks) after analytical treatment interruption, provided that no antibody-resistant HIV was detected at the baseline in the study participants. Similarly, potent HIV suppression was seen in the antiretroviral-therapy-naive study participants with viraemia carrying sensitive virus at the baseline. Our data demonstrate that combination therapy with broadly neutralizing monoclonal antibodies can provide long-term virological suppression without antiretroviral therapy in individuals with HIV, and our experience offers guidance for future clinical trials involving next-generation antibodies with long half-lives.

Distinct mechanisms of long-term virologic control in two HIV-infected individuals after treatment interruption of anti-retroviral therapy.

Certain infected individuals suppress human immunodeficiency virus (HIV) in the absence of anti-retroviral therapy (ART). Elucidating the underlying mechanism(s) is of high interest. Here we present two contrasting case reports of HIV-infected individuals who controlled plasma viremia for extended periods after undergoing analytical treatment interruption (ATI). In Participant 04, who experienced viral blips and initiated undisclosed self-administration of suboptimal ART detected shortly before day 1,250, phylogenetic analyses of plasma HIV env sequences suggested continuous viral evolution and/or reactivation of pre-existing viral reservoirs over time. Antiviral CD8+ T cell activities were higher in Participant 04 than in Participant 30. In contrast, Participant 30 exhibited potent plasma-IgG-mediated neutralization activity against autologous virus that became ineffective when he experienced sudden plasma viral rebound 1,434 d after ATI due to HIV superinfection. Our data provide insight into distinct mechanisms of post-treatment interruption control and highlight the importance of frequent monitoring of undisclosed use of ART and superinfection during the ATI phase.

Kinetics of Plasma HIV Rebound in the Era of Modern Antiretroviral Therapy.

Historical data regarding time to viral rebound following analytical treatment interruption (ATI) have been used to determine therapeutic efficacy in HIV cure trials; however, such data were collected from studies conducted a decade or more ago and included participants receiving older antiretroviral therapy (ART) regimens with infrequent virologic monitoring. We conducted a study of 22 HIV-infected participants receiving modern ART to determine the kinetics of plasma viral rebound following ATI. Our data suggest that modern ART does not alter kinetics of viral rebound when compared to previous regimens and that immunologic interventions may be necessary to achieve ART-free virologic remission. Clinical Trials Registration ClinicaTrials.gov identifier: NCT03225118.