A Study to Determine Whether 2 Investigational Malaria Vaccines Are Safe, Protective Against Malaria in Adults
The purpose of this study is to determine whether 2 investigational malaria vaccines are safe as well as protective against malaria in adults living in the United States
Biological: FMP 2.1 is a recombinant protein of apical membrane antigen-1 (AMA-1) of 3D7 strain of Plasmodium falciparum, and AS01B & AS02A are proprietary adjuvants of GSK
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Primary Purpose: Prevention
|Official Title:||Phase I/IIa Study of the Safety, Immunogenicity and Preliminary Efficacy After Sporozoite Challenge of FMP2.1/AS01B and FMP2.1/AS02A Candidate Malaria Vaccines Administered Intramuscularly at Months 0, 1, and 2 in Malaria-naive Adults Living in the United States|
- Occurrence of solicited symptoms over a 7 day follow-up period after each immunization
- Occurrence of unsolicited symptoms over a 30 day follow-up period after each immunization
- Occurrence of serious adverse events during the study period.
- Anti-AMA-1 antibody titers during Immunization Phase for Cohorts 1&2,and Challenge Phase for Cohort 2,Functionality of anti-AMA-1 antibodies as percent parasite growth inhibition as measured by standardized homologous and heterology
- Development and time to parasitemia after primary challenge following administration of the candidate vaccines(50 µg/0.5 mL dose formulations only)
|Study Start Date:||September 2006|
|Study Completion Date:||April 2007|
35 volunteers aged 18 to 50 years will be enrolled to receive one of 2 investigational malaria vaccines. The vaccines are made of a malaria protein FMP2.1 mixed in 2 different adjuvants (AS01B and AS02A). Five volunteers will get a small (10 µg) dose of FMP2.1/AS01B since this vaccine has not yet been in humans. If it is safe, then 15 volunteers will get 50 µg FMP2.1 in AS02A and 15 will get 50 µg FMP2.1 in AS01B. All vaccines are given IM in the deltoid of the non-dominant arm, every 1 month for 3 months. After vaccination, the subjects will follow up at clinical trials for evaluation of any adverse events.
20 vaccinees (10 from each 50 µg vaccine group) will undergo primary sporozoite challenge 14-30 days after dose 3 via bite of 5 malaria-infected mosquitoes. All subjects will have a blood slide prepared and read to check for asexual P. falciparum parasitemia at least once daily beginning day 5 post challenge. Beginning on day 10 post challenge, subjects will check into a designated hotel, where 24 hour evaluation and care will be available for 10 nights. After this hotel phase, there will be follow-up visits to ensure there are no late developments of malaria in those who have not fallen ill (and thus are considered protected).
Any subject who tests positive for malaria will be treated with chloroquine. Efficacy readouts are complete protection or significant delay in patency defined as >2 days than the median prepatent period for the 6 infectivity controls. These 6 controls receive no vaccine and are enrolled for malaria-challenge only in order to provide comparison group for vaccinated individuals.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00385047
|United States, Maryland|
|Clinical Trials Center, Walter Reed Army Institute of Research|
|Silver Spring, Maryland, United States, 20910|
|Principal Investigator:||Michele D. Spring, MD, M.S.P.H.||Walter Reed Army Institute of Research (WRAIR)|