NMRC-M3V-Ad-PfCA Vaccine - Clinical Trial 1

Plasmodium Falciparum Clinical Trial

Official title: A Two Part Clinical Trial Assessing the Safety, Tolerability, Immunogenicity and Protective Efficacy of NMRC-M3V-Ad-PfCA, a Multivalent, Adenovirus-Vectored Plasmodium Falciparum Malaria Vaccine, in Healthy, Malaria-Naïve Adults

Status Completed

Clinical Trial Summary

The purpose of this study is to determine whether a new investigational malaria vaccine is safe, well tolerated and effective against experimental exposure to malaria when given to healthy people with no previous exposure to malaria. The vaccine consists of a modified form of a relatively common virus, adenovirus, that has been rendered incapable of replicating itself and modified to deliver the malaria gene of interest to the body's cells allowing the cell to manufacture the protein encoded by the gene and present it to the body's immune system in a more natural and presumably effective way.

Clinical Trial Description

The vaccine, called NMRC-M3V-Ad-PfCA (key: NMRC + Multi-antigen Multi-stage, Malaria Vaccine + Adenovectored + P. falciparum CSP & AMA1 antigens), is a combination of two recombinant adenovirus-derived constructs (adenovectors), one expressing the pre-erythrocytic stage antigen circumsporozoite protein (CSP) and the other expressing the erythrocytic stage antigen Apical Membrane Antigen 1 (AMA1), both from the 3D7 strain of P. falciparum. The vector is an attenuated, replication-deficient adenovirus derived from wildtype serotype 5 adenovirus through the deletion of several genes. The vaccine is formulated in a buffered saline solution (Final Formulation Buffer = FFB).

This is a Phase 1/2a, randomized, open-label, dose-escalating trial of the NMRC-M3V-Ad-PfCA vaccine administered intramuscularly to healthy, malaria-naïve adult volunteers. All volunteers will be seronegative (< 1:500, by a luciferase-based neutralizing antibody assay; VRC, Bethesda) for adenovirus serotype 5. In the first part of the study (dose-escalation phase, Part A), 1 x 10^10 particle units (pu) per construct or 2 x 10^10 pu total will be administered to six volunteers as a single dose to assess safety, and 4 weeks later, 5 x 10^10 pu per construct or 1 x 10^11 pu total dose (five-fold dose escalation) will be administered to six additional volunteers. In the second part of the study (regimen-comparison phase, Part B), three regimens for administration will be compared: one dose, two doses administered ten days apart, and two doses administered 16 weeks apart. Separate groups will receive one dose of the individual components of the vaccine (NMRC-MV-Ad-PfC and NMRC-MV-Ad-PfA). Following immunization, volunteers participating in the regimen-comparison phase as well as several non-immunized control volunteers (serving as infectivity controls) will be challenged with P. falciparum sporozoites in order to assess vaccine efficacy against non-immunized controls challenged at the same time. The proposed design of the regimen-comparison phase will provide information to direct selection of an appropriate dosing regimen for subsequent studies, and will also indicate whether the two constituent antigens, when co-formulated, act synergistically, independently, or interfere with each other in the induction of antigen-specific immune responses and protective immunity. ;

Related Conditions & MeSH terms

• Malaria
• Plasmodium Falciparum

• NCT number: NCT00392015
• Study type: Interventional
• Source: U.S. Army Medical Research and Development Command
• Status: Completed
• Phase: Phase 1/Phase 2
• Start date: October 12, 2006
• Completion date: September 25, 2017