Regimen Optimization Trial of PfSPZ Vaccine in Equatorial Guinea

Malaria Clinical Trial

Official title: Randomized, Double-Blind, Placebo-Controlled, Regimen Optimization Study of a Radiation-Attenuated Plasmodium Falciparum (Pf) Sporozoite Vaccine (PfSPZ Vaccine) in Equatoguinean Adults

Status Completed

Clinical Trial Summary

This is a phase 1, randomized regimen optimization study of PfSPZ Vaccine in healthy Equatoguinean volunteers to determine if a condensed, rapid immunization regimen is safe and efficacious. Four different regimens 4 weeks or less in duration will be evaluated for safety, tolerability, immunogenicity, and protective efficacy in comparison to a gold standard 16-week regimen.

Clinical Trial Description

This double-blind, placebo-controlled clinical trial will be conducted in 104 Equatoguinean healthy men and women 18-45 years of age divided into four groups of 26 subjects receiving one of four dosing regimens. The study is designed to test the hypothesis that 2 or 4 doses of 9x10^5 PfSPZ of PfSPZ Vaccine administered by direct venous inoculation (DVI) over 6-7 days as the priming immunization, with or without a boosting immunization at 4 or 16 weeks after the last priming dose, will (1) be safe and well tolerated; and (2) induce immunity leading to protection against homologous controlled human malaria infection (CHMI) performed at 8 weeks after the final immunization by DVI injection of PfSPZ Challenge. The first regimen will test the radiation-attenuated whole sporozoite PfSPZ Vaccine in a dose of 9.0x10^5 administered by DVI with four priming immunizations followed by a boost after 16 weeks. The second regimen will follow the same dosing and administering schedule, but without the boost after 16 weeks to study if a boost may be necessary. The third regimen will follow the first regimen with the interval duration to the boost shortened to only 4 weeks. In the fourth and final regimen, the vaccine will be administered two times instead of four followed by a boost in 4 weeks to evaluate if two priming immunizations will be sufficient to confer protection. In summary:

• Group 1: 21 subjects will receive 9.0x10^5 PfPSZ and 5 subjects will receive normal saline (NS) placebo on Days 1, 3, 5, 7, and 113.

• Group 2: 21 subjects will receive 9.0x10^5 PfPSZ and 5 subjects will receive NS on Days 1, 3, 5, and 7.

• Group 3: 21 subjects will receive 9.0x10^5 PfPSZ and 5 subjects will receive NS on Days 1, 3, 5, 7, and 29.

• Group 4: 21 subjects will receive 9.0x10^5 PfPSZ and 5 subjects will receive NS on Days 1 and 8.

The safety and tolerability of each regimen will be measured by recording (1) solicited and unsolicited adverse events, (2) immunogenicity by assessing humoral and cellular immune responses pre- and post-vaccination, and (3) vaccine efficacy (VE) by measuring protection against homologous CHMI administered by DVI of PfSPZ Challenge (NF54) at 8 weeks post-final vaccination. ;

Related Conditions & MeSH terms

• Malaria

• NCT number: NCT03590340
• Study type: Interventional
• Source: Sanaria Inc.
• Status: Completed
• Phase: Phase 1
• Start date: July 30, 2018
• Completion date: March 12, 2019