Safety and Immunogenicity of Direct Venous Inoculation of a Radiation-attenuated PfSPZ Vaccine in Equatoguinean Adults

Malaria Clinical Trial

Official title: Phase 1, Randomized, Double-blind, Placebo-controlled Trial to Evaluate the Safety and Immunogenicity of Direct Venous Inoculation of a Radiation-attenuated Plasmodium Falciparum Sporozoite Vaccine (PfSPZ Vaccine) in Equatoguinean Adults

Status Completed

Clinical Trial Summary

This is a single center, randomized, placebo-controlled, double-blind trial to assess the safety and immunogenicity of PfSPZ Vaccine administered by direct venous inoculation (DVI).

The study to be conducted in Baney District, Bioko Island, Equatorial Guinea (EG), will be to establish whether three doses of the higher regimen - three doses of 2.7x10^5 PfSPZ of the PfSPZ Vaccine administered at 8 week intervals - is as well-tolerated and efficacious in malaria exposed African adults as the five dose regimens. Specifically, the trial will address the following objectives: is the three dose regimen:

1. Safe and well tolerated in Equatoguinean (EG) adults.

2. As immunogenic in EG adults as is the five-dose regimen of 1.35x10^5 PfSPZ in Tanzanian and U.S. adults or as three-, four- and five-dose regimens of 2.7x10^5 PfSPZ being tested in Tanzanian, Malian and U.S. adults.

In addition, as an exploratory objective, the volunteers in the EG trial will be followed longitudinally to measure the incidence of malaria during the initial six months following immunization, providing a preliminary assessment of efficacy.

Clinical Trial Description

This is a single center, Phase 1, randomized, double-blind, placebo-controlled trial. Thirty-three healthy male volunteers, aged 18 to 35 years will be recruited into three groups. The first group will be comprised of 3 volunteers who will be vaccinated first before the rest for demonstration of safety. The safety volunteers will receive 2 escalating doses of PfSPZ vaccine at a two week interval, 1.35x10^5 and 2.7x10^5 PfSPZ. The second group of 14 - 20 volunteers will receive three vaccinations of 2.7x10^5 PfSPZ that will be given at 0, 8 and 16 weeks (in the Tanzania trial, volunteers will receive a five dose regimen at 0, 4, 8, 12 and 18 weeks). The third group of 7 - 10 volunteers will act as control group for group 2 and will receive three injections of normal saline at 0, 8 and 16 weeks respectively.

Volunteers in groups 2 and 3 will only be injected when the Safety Monitoring Committee (SMC) provides clearance based on the results from the sentinel 3 volunteers (group 1). For groups 2 and 3, five volunteers will be vaccinated with the first dose before the remaining volunteers are vaccinated on a subsequent day.

The control volunteers will help better assess the occurrence of adverse events compared to background disease patterns that occur in this tropical area. The decision to dose escalate in group 1 and to immunize a larger number of volunteers in group 2 in Bioko will be made with full knowledge of all safety data generated in other ongoing trials where the PfSPZ Vaccine is being tested. ;

Study Design

Allocation: Randomized, Endpoint Classification: Safety Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Malaria
• Plasmodium Falciparum

• NCT number: NCT02418962
• Study type: Interventional
• Source: Sanaria Inc.
• Status: Completed
• Phase: Phase 1
• Start date: March 2015
• Completion date: February 2016