Date: 2014-11-11
Type of information: Initiation of preclinical development
phase: preclinical
Announcement: presentation of results at the 9th International Respiratory Syncytial Virus (RSV) Symposium being held in South Africa
Company: Genvec (USA - MD)
Product: GV2311
Action
mechanism: vaccine. GV2311 is a single adenovector construct expressing the RSV F protein. The vaccine candidate utilizes a proprietary vector built from gorilla adenovirus, designed to show superior performance while avoiding the pre-existing immunity issues that have hampered delivery using other adenovector constructs. GV2311 is produced on a proprietary human cell line for high vector productivity.
Disease: Respiratory Syncytial Virus (RSV) infection
Therapeutic area: Infectious diseases
Country:
Trial details:
Latest
news: * On November 11, 2014, GenVec announced that data exploring the immune responses generated by its vaccine candidate, GV2311, were presented at the 9th International Respiratory Syncytial Virus (RSV) Symposium being held in South Africa. These data were presented by Dr. Teresa R. Johnson, Chair of the Microbiology and Immunology Department of the Edward College of Osteopathic Medicine in Virginia. GV2311 utilizes GenVec's proprietary gorilla adenovector platform. These vectors are designed to produce superior performance in gene-based vaccines, including induction of durable high-level antibody responses as well as high-level T cell responses. They have also been shown to induce increased immune responses on repeat administration. In the experiments described in the presentation, kinetics of RSV clearance in RSV and GV2311 immunized mice were determined on days 1 and 5 post-infection with low dose (105 plaque-forming units, PFU) and with high dose (106 PFU) RSV A2 challenge. Vaccine-induced T cells were evaluated in BALB/c mice immunized with RSV or GV2311 by in vivo depletion of CD4 and CD8 T cells (alone or in combination) at challenge. Similarly, wild-type or Jh transgenic mice (deficient in antibodies and mature B cells) were immunized, then challenged with RSV. Neutralizing antibody, RSV titers, and T cell function were measured in all experiments. RSV immunized mice had no detectable virus following low dose challenge, while breakthrough RSV replication in both lungs and noses was rapidly controlled upon high dose challenge. GV2311 immunization fully protected the lungs at both challenge doses with partial protection in noses. The studies also confirm that the major protective mechanism is through induction of antibodies against RSV, although antigen specific T cells contribute to viral clearance in the absence of antibody. GV2311 was previously shown to induce protective immunity to RSV in a dose-dependent manner in established animal models.
