This Phase 1/2a study, completed in Oxford, Southampton, and London, United Kingdom, aimed to evaluate the falciparum malaria protein 2.1 (FMP2.1)/AS01B apical membrane antigen 1 (AMA-1) asexual blood-stage challenge model in malaria-naïve adults as an early clinical stage-gate for informing asexual blood-stage vaccine development.
The study was designed with three objectives:
- Evaluate controlled human malaria infection as a reliable and reproducible model in assessing malaria vaccine candidates.
- Assess the safety and reactogenicity of the FMP2.1/AS01B vaccine in malaria-naïve adults by monitoring for occurrence of solicited signs and symptoms, occurrence of unsolicited symptoms, and the occurrence of serious adverse events during the study period.
Quantify humoral immune response via antibody titer.
Outcomes/Next steps: Study results were presented at the American Society of Tropical Medicine and Hygiene Annual Meeting in 2014, and were published in The Journal of Infectious Diseases in 2016.
FMP2.1/AS01B was found to be well-tolerated, with low systemic reactogenicity in subjects. Although the vaccine was immunogenic, it demonstrated no efficacy after blood-stage challenge; however, the controlled human malaria infection model induced highly reproducible infection in all subjects.
Based on the outcomes of this study, the PATH Malaria Vaccine Initiative did not make further investments.
Payne RO, Milne KH, Elias SC, Edwards NJ, Douglas AD, et al. Demonstration of the blood-stage Plasmodium falciparum controlled human malaria infection model to assess efficacy of the P. falciparum apical membrane antigen 1 vaccine, FMP2.1/AS01. The Journal of Infectious Diseases. 2016;213(11):1743-1751.
This project was supported by the PATH Malaria Vaccine Initiative through the United States Agency for International Development, Bureau for Global Health, Infectious Disease Division, under the terms of Cooperative Agreement GHS-A-00-04-00016-00.