Safety and immunogenicity of an HIV-1 gp120-CD4 chimeric subunit vaccine in a phase 1a randomized controlled trial.

A major challenge for HIV vaccine development is to raise anti-envelope antibodies capable of recognizing and neutralizing diverse strains of HIV-1. Accordingly, a full length single chain (FLSC) of gp120-CD4 chimeric vaccine construct was designed to present a highly conserved CD4-induced (CD4i) HIV-1 envelope structure that elicits cross-reactive anti-envelope humoral responses and protective immunity in animal models of HIV infection. IHV01 is the FLSC formulated in aluminum phosphate adjuvant. We enrolled 65 healthy adult volunteers in this first-in-human phase 1a randomized, double-blind, placebo-controlled study with three dose-escalating cohorts (75 µg, 150 µg, and 300 µg doses). Intramuscular injections were given on weeks 0, 4, 8, and 24. Participants were followed for an additional 24 weeks after the last immunization. The overall incidence of adverse events (AEs) was not significantly different between vaccinees and controls. The majority (89%) of vaccine-related AE were mild. The most common vaccine-related adverse event was injection site pain. There were no vaccine-related serious AE, discontinuation due to AE, intercurrent HIV infection, or significant decreases in CD4 count. By the final vaccination, all vaccine recipients developed antibodies against IHV01 and demonstrated anti-CD4i epitope antibodies. The elicited antibodies reacted with CD4 non-liganded Env antigens from diverse HIV-1 strains. Antibody-dependent cell-mediated cytotoxicity against heterologous infected cells or gp120 bound to CD4+ cells was evident in all cohorts as were anti-gp120 T-cell responses. IHV01 vaccine was safe, well tolerated, and immunogenic at all doses tested. The vaccine raised broadly reactive humoral responses against conserved CD4i epitopes on gp120 that mediates antiviral functions.

Short-duration treatment with the novel non-nucleoside inhibitor CDI-31244 plus sofosbuvir/velpatasvir for chronic hepatitis C: An open-label study.

Combination regimens of direct-acting antiviral agents (DAAs) for chronic genotype 1 hepatitis C virus (HCV) infection given for 8 or 12 weeks have high cure rates. Shortened treatment durations that maintain high cure rates may lessen treatment barriers related to affordability and drug adherence. We enrolled 12 treatment-naïve adults with chronic genotype 1 HCV infection without cirrhosis in a single-center, open-label trial to receive 2 weeks of the highly potent and selective non-nucleoside inhibitor (NNI) CDI-31244 concurrent with 6 weeks of sofosbuvir/velpatasvir. The main efficacy endpoints were sustained virologic response at 12 (SVR12) and 24 (SVR24) weeks after treatment completion. In all patients, plasma HCV RNA levels rapidly decreased during the first 2 days of treatment and were below the lower limit of quantification by the end of the 6-week treatment period. Eight of 12 (67%) patients achieved both SVR12 and SVR24. Four patients had virological relapse at Week 10, 4 weeks after end of treatment. The most common adverse event was headache, occurring in five (42%) patients. Pharmacokinetic analysis showed no relevant drug interactions between CDI-31244, sofosbuvir, and velpatasvir. In this pilot study of short-duration combination therapy involving a novel NNI with a fixed-combination DAA, 8 of 12 treatment-naïve patients with chronic genotype 1 HCV infection without cirrhosis achieved virologic cure. Future trials might evaluate whether extending the NNI duration beyond 2 weeks with combination DAAs results in higher cure rates comparable with currently approved longer duration therapy.