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Summary Background A preventive vaccine for HIV is a crucial public health need; adeno-associated virus (AAV)-mediated antibody gene delivery could be an alternative to immunisation to induce sustained expression of neutralising antibodies to prevent HIV. We assessed safety and tolerability of rAAV1-PG9DP, a recombinant AAV1 vector encoding the gene for PG9, a broadly neutralising antibody against HIV. Methods This first-in-human, proof-of-concept, double-blind, phase 1, randomised, placebo-controlled, dose-escalation trial was done at one clinical research centre in the UK. Healthy men aged 18–45 years without HIV infection were randomly assigned to receive intramuscular injection with rAAV1-PG9DP or placebo in the deltoid or quadriceps in one of four dose-escalating cohorts (group A, 4 × 10 12 vector genomes; group B, 4 × 10 13 vector genomes; group C, 8 × 10 13 vector genomes; and group D, 1·2 × 10 14 vector genomes). Volunteers were followed up for 48 weeks. The primary objective was to assess safety and tolerability. A secondary objective was to assess PG9 expression in serum and related HIV neutralisation activity. All volunteers were included in primary and safety analyses. The trial is complete and is registered with ClinicalTrials.gov, number NCT01937455. Findings Between Jan 30, 2014, and Feb 28, 2017, 111 volunteers were screened for eligibility. 21 volunteers were eligible and provided consent, and all 21 completed 48 weeks of follow-up. Reactogenicity was generally mild or moderate and resolved without intervention. No probably or definitely related adverse events or serious adverse events were recorded. We detected PG9 by HIV neutralisation in the serum of four volunteers, and by RT-PCR in muscle biopsy samples from four volunteers. We did not detect PG9 by ELISA in serum. PG9 anti-drug antibody was present in ten volunteers in the higher dose groups. Both anti-AAV1 antibodies and AAV1-specific T-cell responses were detected. Interpretation Future studies should explore higher doses of AAV, alternative AAV serotypes and gene expression cassettes, or other broadly neutralising HIV antibodies. Funding International AIDS Vaccine Initiative, United States Agency for International Development, Bill & Melinda Gates Foundation, US National Institutes of Health.

Background: A preventive vaccine for HIV is a critical public health need. Adeno-associated virus (AAV) mediated antibody gene delivery could be an alternative to immunization to induce sustained expression of neutralizing antibodies to prevent HIV. We conducted a first-in-human, phase 1 study of rAAV1-PG9DP, a recombinant AAV1 vector encoding the gene for PG9, a broadly neutralizing antibody against HIV. Methods: The trial was a phase 1, randomized, blinded, placebo-controlled, dose-escalation study at a single center in the UK. Healthy, HIV-uninfected men aged 18-45 were randomly assigned (3:1) to intervention or control in one of four dose-escalating cohorts (4x1012 vector genomes(vg), 4x1013 vg, 8x1013 vg or 1·2x1014 vg). Volunteers received intramuscular injection with rAAV1-PG9DP or placebo in the deltoid or quadriceps and were followed for 48 weeks. The primary objective was safety and tolerability. A secondary objective was to evaluate PG9 expression in serum and related HIV neutralization activity. This trial is registered with ClinicalTrials.gov, number NCT01937455. Findings: 21 volunteers were enrolled between February 10, 2014 and February 28, 2017 and completed 48 weeks follow-up. Reactogenicity was generally mild or moderate and self-limited. There were no probably or definitely related adverse events and no serious adverse events. We detected PG9 by HIV neutralization in serum of four volunteers, and by RT-PCR in muscle biopsies of four volunteers. We did not detect PG9 by ELISA in serum. PG9 anti-drug antibody was present in 10 volunteers in the higher dose groups. Both anti-AAV1 antibodies and AAV1 specific T-cell responses were detected. Interpretation: Intramuscular administration of rAAV1-PG9DP in healthy men was safe and well-tolerated. Antibody expression was detected directly in muscle and indirectly in serum, and anti-drug antibodies were induced, indicating PG9 expression. Future studies should explore higher doses of AAV, alternative AAV serotypes and gene expression cassettes, or other broadly neutralizing HIV antibodies. Trial Registration number: This trial is registered with ClinicalTrials.gov, number NCT01937455. Funding: International AIDS Vaccine Initiative, United States Agency for International Development (USAID), Bill & Melinda Gates Foundation, US National Institutes of Health Declaration of Interest: Jim Ackland reports receiving consulting fees from International AIDS Vaccine Initiative during the course of the study. Fraser Wright reports grants from National Institutes of Health during the conduct of the study. In addition, Dr. Wright has a patent US 9,408,904 licensed to Spark Therapeutics. Ethical Approval: The protocol was approved by the University of Surrey Ethics Committee, the NRES Bristol Research Ethics Committee and the UK Medicines and Healthcare products Regulatory Authority and conducted in compliance with Good Clinical Practices and the Declaration of Helsinki guidelines.

In October 2009, The International AIDS Vaccine Initiative (IAVI) convened a satellite symposium entitled 'Replicating Viral Vectors for use in AIDS Vaccines' at the AIDS Vaccine 2009 Conference in Paris. The purpose of the symposium was to gather together researchers, representatives from regulatory agencies, and vaccine developers to discuss issues related to advancement of replication-competent viral vector- based HIV vaccines into clinical trials. The meeting introduced the rationale for accelerating the development of replicating viral vectors for use as AIDS vaccines. It noted that the EMEA recently published draft guidelines that are an important first step in providing guidance for advancing live viral vectors into clinical development. Presentations included case studies and development challenges for viral vector-based vaccine candidates. These product development challenges included cell substrates used for vaccine manufacturing, the testing needed to assess vaccine safety, conducting clinical trials with live vectors, and assessment of vaccination risk versus benefit. More in depth discussion of risk and benefit highlighted the fact that AIDS vaccine efficacy trials must be conducted in the developing world where HIV incidence is greatest and how inequities in global health dramatically influence the political and social environment in developing countries.

This report summarizes the discussions and recommendations from a consultation held in New York City, USA (31 January-2 February 2006) organized by the joint World Health Organization-United Nations Programme on HIV/AIDS HIV Vaccine Initiative and the International AIDS Vaccine Initiative. The consultation discussed issues related to the design and implementation of phase IIB 'test of concept' trials (phase IIB-TOC), also referred to as 'proof of concept' trials, in evaluating candidate HIV vaccines and their implications for future approval and licensure. The results of a single phase IIB-TOC trial would not be expected to provide sufficient evidence of safety or efficacy required for licensure. In many instances, phase IIB-TOC trials may be undertaken relatively early in development, before manufacturing processes and capacity are developed sufficiently to distribute the vaccine on a large scale. However, experts at this meeting considered the pressure that could arise, particularly in regions hardest hit by AIDS, if a phase IIB-TOC trial showed high levels of efficacy. The group largely agreed that full-scale phase III trials would still be necessary to demonstrate that the vaccine candidate was safe and effective, but emphasized that governments and organizations conducting trials should consider these issues in advance. The recommendations from this meeting should be helpful for all organizations involved in HIV vaccine trials, in particular for the national regulatory authorities in assessing the utility of phase IIB-TOC trials in the overall HIV vaccine research and development process. (c) 2007 Lippincott Williams & Wilkins.

Background HIV Gag-specific CD4+ and CD8+ T-cell responses are important for HIV immune control. Pulsing overlapping Gag peptides on autologous lymphocytes (OPAL) has proven immunogenic and effective in reducing viral loads in multiple pigtail macaque studies, warranting clinical evaluation. Methodology We performed a phase I, single centre, placebo-controlled, double-blinded and dose-escalating study to evaluate the safety and preliminary immunogenicity of a novel therapeutic vaccine approach ‘OPAL-HIV-Gag(c)’. This vaccine is comprised of 120 15mer peptides, overlapping by 11 amino acids, spanning the HIV Gag C clade sequence proteome, pulsed on white blood cells enriched from whole blood using a closed system, followed by intravenous reinfusion. Patients with undetectable HIV viral loads (

Background Preclinical studies of overlapping 15mer peptides, spanning SIV, SHIV or HIV, pulsed on autologous PBMC ex vivo have demonstrated high level, virus-specific T cell responses and viral suppression in non-human primates (NHP). Opal-HIV-Gag(c) consists of 120 synthetic 15mer peptides spanning Clade C, consensus Gag, manufactured to current good manufacturing practice; having been evaluated in a good laboratory practice toxicology study in Macaca mulatta. We evaluated the safety and preliminary immunogenicity of such peptides administered intravenously after short-duration ex vivo incubation, to HIV-positive adults on suppressive antiretroviral therapy. Methods and Findings A first-in-human, placebo-controlled, double-blind, dose escalation study was conducted. Twenty-three patients with virus suppressed by antiretroviral therapy were enrolled in four groups 12 mg (n = 6), 24 mg (n = 6), 48 mg (n = 2) or matching placebo (n = 8). Treatment was administered intravenously after bedside enrichment of 120 mL whole blood for white cells using a closed system (Sepax S-100 device), with ex vivo peptide admixture (or diluent alone) and 37°C incubation for one hour prior to reinfusion. Patients received 4 administrations at monthly intervals followed by a 12-week observation post-treatment. Opal-HIV-Gag(c) was reasonably tolerated at doses of 12 and 24 mg. There was an increased incidence of temporally associated pyrexia, chills, and transient/self-limiting lymphopenia in Opal-HIV-Gag(c) recipients compared to placebo. The study was terminated early, after two patients were recruited to the 48 mg cohort; a serious adverse event of hypotension, tachycardia secondary to diarrhoea occurred following a single product administration. An infectious cause for the event could not be identified, leaving the possibility of immunologically mediated product reaction. Conclusions A serious, potentially life-threatening event of hypotension led to early, precautionary termination of the study. In the absence of a clearly defined mechanism or ability to predict such occurrence, further development of Opal-HIV-Gag(c) will not be undertaken in the current form. Registration ClinicalTrials.gov NCT01123915; EudraCT: 2008-005142-23