This is a phase I, single-site, dose escalation study to evaluate the safety, immunogenicity, and efficacy of the recombinant circumsporozoite protein (rCSP) antigen malaria vaccine administered with and without AP 10-602 [Glucopyranosyl Lipid A (GLA) in liposome Quillaja saponaria 21 formulation (LSQ)]. The study population will consist of 65 healthy male and female adults aged 18 to 45 years old and be conducted at the Center for Vaccine Development (CVD) in Baltimore, Maryland. 49 healthy, malaria-naïve volunteers will receive rCSP vaccination with AP 10-602 [GLA-LSQ] adjuvant. Ten volunteers will receive rCSP alone. Each dose-escalating group will receive 3 intramuscular (IM) total doses of vaccine on days 1, 29, and 85. Group 1 will receive a dose of 10 mcg rCSP + AP 10-602 [GLA-LSQ] (5 mcg GLA - 2 mcg LSQ) at each injection; Group 2 will receive 30 mcg rCSP + AP 10-602 [GLA-LSQ] (5 mcg GLA - 2 mcg LSQ); Group 3 will receive 30 mcg rCSP without adjuvant; and Group 4 will receive 60 mcg rCSP + AP 10-602 [GLA-LSQ] (5 mcg GLA - 2 mcg LSQ). The dose for Group 5 will depend on immunogenicity analysis from groups 1, 2 and 3. If immunogenicity analysis conducted 28 days post-2nd dose in Groups 1, 2 and 3 show promise (at least fourfold increase in geometric mean anti-CSP antibody or geometric mean anti-CSP titer of 20), the 10 volunteers in Group 5 will receive the lowest rCSP dose that gives this predefined immunogenic response ((either 10 or 30 mcg rCSP) + AP 10-602 [GLA-LSQ],]), otherwise, Group 5 will receive 60 mcg rCSP + AP 10-602 [GLA-LSQ]. Groups will be vaccinated in a stepwise manner following a telescoped design. A sixth group of 6 volunteers (Group 6) will receive no vaccinations and will be used as an infectivity control for a Controlled Human Malaria Infection (CHMI) challenge. Groups 4 and 5 will also undergo the CHMI challenge together, 28 days after the last vaccination. The patient participation duration is expected to be up to 886 days for Groups 1, 2, 3, 4, and 5; and up to 117 days for Group 6. This study will test two hypotheses: (1) the rCSP/AP 10-602 [GLA-LSQ] candidate malaria vaccine will induce an immune response in a dose-dependent manner as measured by anti-CSP antibody titer via ELISA and (2) the rCSP/AP 10-602 [GLA-LSQ] candidate malaria vaccine will provide a minimum of 50% efficacy in vaccines compared to unvaccinated infectivity controls. The primary objective is to assess the safety and reactogenicity of candidate rCSP/AP 10-602 [GLA-LSQ] malaria vaccine when administered intramuscularly on a 1, 29, and 85 day schedule (Groups 1-3, 4B, 5) and on a 1 and 461 day schedule (Group 4) to healthy malaria-naive adults aged 18-45 years. The secondary objectives are to (1) assess immunogenicity of rCSP/AP 10-602 [GLA-LSQ] malaria vaccine when administered intramuscularly on a 1, 29, and 85 day (Groups 1-3, 4B, 5) and on a 1 and 490 day schedule (Group 4) schedule and (2) to assess the preliminary efficacy of candidate rCSP/AP 10-602 [GLA-LSQ] malaria vaccine against infection with Plasmodium falciparum malaria (defined as P. falciparum asexual parasitemia or a delay in patency of infection > 2 days versus unimmunized infectivity controls) under Controlled Human Malaria Infection (CHMI).
This is a study to evaluate the safety, immunogenicity, and efficacy of a recombinant circumsporozoite protein (rCSP) malaria vaccine administered with and without AP 10-602 [Glucopyranosyl Lipid A (GLA) in liposome Quillaja saponaria 21 formulation (LSQ)] adjuvant. 59 healthy adult, malaria naive volunteers aged 18 to 45 will receive vaccination with or without adjuvant (10 of those volunteers will receive rCSP alone) in five dose escalating groups. Each group will receive 3 vaccination doses total, with intramuscular (IM) injections on days 1, 29, and 85. A sixth group of 6 volunteers will receive no vaccinations and will participate as a control in a Controlled Human Malaria Infection (CHMI) challenge with two of the vaccinated groups. The study will be conducted at the Center for Vaccine Development (CVD) in Baltimore, Maryland. The patient participation duration is expected to be up to 886 days (up to 117 days for nonvaccination group). This study will test two hypotheses: (1) the rCSP/AP 10-602 [GLA-LSQ] candidate malaria vaccine will induce an immune response in a dose-dependent manner as measured by anti-CSP antibody titer via ELISA and (2) the rCSP/AP 10-602 [GLA-LSQ] candidate malaria vaccine will provide a minimum of 50% efficacy in vaccines compared to unvaccinated infectivity controls. The primary objective is to assess the safety and reactogenicity of candidate rCSP/AP 10-602 [GLA-LSQ] malaria vaccine when administered intramuscularly on a 1, 29, and 85 day schedule (Groups 1-3, 4B, 5) and on a 1 and 490 day schedule (Group 4) to healthy malaria-naive adults aged 18-45 years.