Sanaria's malaria vaccine is one step closer to challenging GlaxoSmithKline's Mosquirix, thanks to data from a recent clinical trial in 67 patients. Encouraged by the study results, Sanaria is preparing to test the vaccine candidate in a larger group.
A team of scientists from the Naval Medical Research Center and Walter Reed Army Institute of Research—two partners in developing the shot—published the most recent findings in JCI Insight, a publication affiliated with the Journal of Clinical Investigation.
The vaccine prospect, dubbed PfSPZ, already has fast-track status at the FDA, which could speed its path to market. The candidate consists of live malaria parasites that are weakened so they aren't harmful. This trial enlisted 67 adult volunteers and tested the candidate on 45 of them; 22 were in the control group.
Investigators found that the vaccine protected 25 out of 28 subjects who received either three or five 0.5 mL doses. The three-dose course continued to protect 57% of subjects 24 weeks after the final dose.
Sanaria is now advancing PfSPZ with a test in more than 400 infants in Kenya, according to Dr. Martina Oneko, who's heading that trial. According to clinicaltrials.gov, a phase 1/2 trial of the candidate in Kenya is now recruiting patients.
Sanaria founder and CEO Stephen Hoffman said in a statement that the new data “lay a solid foundation" for the larger study as the team works to finalize a dosing regimen needed for licensure.
The company is also planning a phase 3 trial in Equatorial Guinea, with the help of $48.5 million in funding from several energy giants that have large workforces in malaria-endemic areas, as well as the government of that country. Back in September, it won "fast track" review status at the FDA, and Sanaria has scientific support from the National Institutes of Health and the Department of Defense.
It remains to be seen whether the vaccine will face challenges similar to those seen by Glaxo's first-of-a-kind malaria shot, Mosquirix. Without a booster dose, Mosquirix's efficacy dwindled significantly after four years. Even children who received a booster dose—fourth in the series—protection four years after vaccination was not as strong as it was the first year. Another seven-year study published last year threw Mosquirix’s durability into question.
After multiple recent funding commitments, Glaxo's shot is ready to be introduced through pilot projects in sub-Saharan Africa beginning in 2018, per a recommendation by the World Health Organization. The WHO's choice of pilot projects, rather than a broader launch, is seen as a roadblock for the GSK shot, but the candidate doesn’t lack the potential to save lives, and it has already earned backing from the European Medicines Agency.