Age de-escalation trial of transmission blocking vaccine candidate Pfs230D1-EPA/AS01 to assess safety and tolerability in children and community trial to assess efficacy in family compounds

Malaria affects many people in Mali and other parts of Africa. It is spread by mosquito bites. Malaria can make people sick or can lead to death. Scientists want to learn if a vaccine can stop it from spreading to other people. A vaccine to interrupt malaria transmission (VIMT), targeting disruption of both human and mosquito transmission, would be a valuable tool for local elimination or eradication of this disease. One strategy to design a VIMT is using components that block the transmission of malaria to mosquitoes, such as Pfs230. Pfs230, a surface antigen of intracellular gametocytes, as well as extracellular gametes and zygotes in the mosquito stage of Plasmodium falciparum, is currently the leading candidate in clinical trials for a malaria transmission-blocking vaccine (TBV). Recombinant Pfs230D1M has been conjugated to a recombinant Pseudomonas aeruginosa ExoProtein A (EPA) and adjuvanted with AS01. When formulated in AS01, results from a recent first-in-human trial demonstrated that Pfs230-EPA induces functional transmission-reducing, and in a significant proportion of vaccinees, transmission-blocking serum activity that can be measured for months, the vaccine is well-tolerated and safe in adults, and our recent natural history data clearly indicate that children play a disproportionate role in malaria transmission. The next step in the development of Pfs230D1M-EPA as a TBV is therefore to conduct an age de-escalation trial to ensure that the vaccine is safe to administer to children and then to conduct a community clinical trial to assess efficacy in family groups.

Study type: Interventional
Enrollment: 1301 participants
Primary purpose: Prevention
Allocation: Randomized
Interventional Model: Parallel assignment
Masking : Double (Participant, Investigator)
NCT number: NCT03917654
Phase: Phase II

Clinical trial registration

Vaccines (Immune Correlates)

Apr 2024 — Oct 2030

Mali