Inovio Pharmaceuticals, a US-based company developing synthetic DNA vaccines for cancer and infectious diseases using immune-system stimulation and electroporation delivery systems, has agreed a follow-on collaboration with the PATH Malaria Vaccine Initiative (MVI) that will bring a novel vaccine candidate into clinical trials.

Set to begin in early 2014, the Phase 1/IIa challenge study will assess Inovio’s plasmid DNA and electroporation technology in some 30 volunteers, who will be exposed to the malaria parasite following administration of the DNA.

The trial will include two arms. The first will incorporate three antigens – two pre-erythrocytic (CSP and TRAP) and one blood stage (AMA-1) – shown previously to protect against the Plasmodium falciparum strain of malaria.

The second arm will include two additional pre-erythrocytic-stage antigens: LSA-1 and CelTOS.

Leading approach

Delivering multiple antigens simultaneously is a leading approach to developing highly effective malaria vaccines, the two partners noted.

The Inovio platform is technically well suited to this purpose and has demonstrated in preclinical studies an ability to induce potent immune responses to target antigens, they added.

This is one of a series of platforms MVI plans to evaluate for their capacity to induce immune responses that confer protection from malaria infection in the human-challenge model.

Rodent studies

In a previous research and development collaboration undertaken by Inovio and MVI in 2010, Inovio researchers and their academic colleagues developed novel DNA plasmids targeting multiple malaria parasite antigens, and conducted studies in rodents to show induction of broad immune responses.

The success of these studies resulted in an expanded collaboration, in which further testing demonstrated potent T-cell and antibody responses in other animal models, the partners said.

Inovio’s DNA-based vaccine approach involves delivery of plasmid DNA through electroporation, which deploys controlled electrical impulses to create temporary pores in a cell membrane, leading to uptake of the synthetic DNA.