NCT01994525

Immunization Via Mosquito Bite With Radiation-attenuated Sporozoites

Phase 1 Trial With Challenge to Assess the Safety and Biomarkers of Protection in Malaria-naïve Adults of Immunization Via Mosquito Bite With Radiation-Attenuated Plasmodium Falciparum Sporozoites (IMRAS)

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 54 (actual)
• Sponsor: U.S. Army Medical Research and Development Command · Federal
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

This study is to assess the safety, tolerability, and biomarkers of protection in healthy malaria-naïve adults, who will receive bites from Anopheles stephensi mosquitoes either infected with Plasmodium falciparum Sporozoites (PfRAS) (true-immunization) or noninfected (mock-immunization).

Detailed description

This is a Phase 1 open-labeled study. In addition to safety and tolerability of Plasmodium falciparum Sporozoites (PfRAS), this study is a comprehensive, systems biology-based effort to identify and validate biomarkers of protection with PfRAS immunization, comparing sterility protected to nonprotected study subjects. The goal of the trial design is to achieve approximately 50% sterile protection in order to facilitate the identification of biomarkers and correlates of protection. Following true-immunization or mock-immunization, study subjects and nonimmunized infectivity controls will receive a challenge via the bites of 5 An stephensi mosquitoes carrying infectious P falciparum sporozoites within a controlled clinical environment (controlled human malaria infection, CHMI) to determine the level of sterile protection.

Conditions

• Malaria

Interventions

Type	Name	Description
BIOLOGICAL	PfRAS	Radiation-attenuated Plasmodium falciparum sporozoites (PfRAS) administered by the bite of infected Anopheles stephensi mosquitoes
BIOLOGICAL	Placebo	Administered by the bite of noninfected Anopheles stephensi mosquitoes
OTHER	Challenge	5 infectious Anopheles stephensi mosquito bites carrying infectious Plasmodium falciparum sporozoites within a controlled clinical environment.

Timeline

• Start date: 2014-01-24
• Primary completion: 2016-12-20
• Completion: 2017-02-01
• First posted: 2013-11-25
• Last updated: 2019-09-17

Locations

1 site across 1 country: United States