NCT03341754

Trial to Evaluate the Safety, Immunogenicity, and Efficacy of Malaria Infection in Malaria Naïve Adults

A Phase 1 Trial With Controlled Human Malaria Infection to Evaluate the Safety, Immunogenicity, and Protective Efficacy of Two-Antigen and Three-Antigen Plasmodium Falciparum DNA Prime-Adenovirus Boost Malaria Vaccine Regimens in Healthy Malaria Naïve Adults

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 52 (actual)
• Sponsor: U.S. Army Medical Research and Development Command · Federal
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

This is a study designed to assess the safety, tolerability, immunogenicity, and protective efficacy of 2 heterologous prime-boost vaccine regimens in healthy, malaria naïve adults. The study will include 2 vaccine groups and an infectivity control (IC) group consisting of non-immunized subjects. Subjects to be immunized will be randomly assigned to one of two vaccine groups.

Detailed description

This is a study designed to assess the safety, tolerability, immunogenicity, and protective efficacy of 2 heterologous prime-boost vaccine regimens in healthy, malaria naïve adults. The study will include 2 vaccine groups and an infectivity control (IC) group consisting of non-immunized subjects. Subjects to be immunized will be randomly assigned to one of two vaccine groups. Approximately 4 weeks after administration of the boosting immunization the vaccinated groups and the IC group will participate in CHMI wherein subjects will be exposed to the bites of 5 Anopheles stephensi mosquitoes carrying infectious Pf sporozoites within a controlled clinical environment. Protection will be determined by the examination of thick blood smears through 28 days post-CHMI and by retrospective PCR analysis for the presence of blood stage parasites. All groups will be enrolled and evaluated in one cohort. Due to a limit in the number of subjects who can undergo malaria challenge at the facility in one day, CHMI will be conducted over two days. Group 1 (2-antigen): 3 doses at 4 week intervals (Week 0, 4, and 8) of DNA prime with D-C + D-A at 2 mg total (1 mg per construct) per dose as two 1 mL IM injections of the blended D-CA, one in each arm, via Biojector 2000 needle-free injection device or an equivalent disposable syringe needle-free injection device. This will be followed after 16 weeks (Week 24) by 1 dose of ChAd63-C + ChAd63-A boost, at a total dose of 1 x 1011 virus particles (vp) (5 x 1010 vp/construct) as a single IM injection of 0.65mL, using a needle and syringe. Group 2 (3-antigen): 3 doses at 4 week intervals (Week 0, 4, and 8) of DNA prime with D-C + D-A + D-T at 3 mg total (1 mg per construct) per dose as two 1 mL intramuscular (IM) injections of the blended D-CAT, one in each arm, via Biojector 2000 needle-free injection device or an equivalent disposable syringe needle-freeinjection device. This will be followed after 16 weeks (Week 24) by 1 dose of ChAd63-C + ChAd63-A + ChAd63-T boost, at a total dose of 1.5 x 1011 vp (5 x 1010 vp/construct) as a single IM injection of 1.0mL, using a needle and syringe.

Conditions

• Malaria

Interventions

Type	Name	Description
BIOLOGICAL	D/ChAd63-CA	Priming Component (DNA) = NMRC-M3V-D-PfCA (D-CA) Vaccine Boosting Component = ChAd63-PfCA
BIOLOGICAL	D/ChAd63-CAT	Priming Component (DNA) = NMRC-M3V-D-PfCAT (D-CAT) Boosting Component = ChAd63-PfCAT
OTHER	Infectivity Control (IC) Group	Subjects will be exposed to bites of 5 Anopheles stephensi mosquitoes carrying infectious Pf sporozoites within a controlled clinical environment.

Timeline

• Start date: 2018-09-15
• Primary completion: 2019-10-28
• Completion: 2020-03-23
• First posted: 2017-11-14
• Last updated: 2020-05-06

Locations

2 sites across 1 country: United States

Regulatory

• FDA-regulated drug study