Shares of the small drug developer Agenus Inc. jumped in premarket trading Tuesday after the company said a potential malaria vaccine for which it developed a component fared well in a late-stage study.
The Lexington, Mass., company said results from the research showed that a potential vaccine developed by GlaxoSmithKline PLC helped protect young children and infants from clinical malaria for up to 18 months after vaccination. The vaccine contains a component labeled QS-21 Stimulon developed by Agenus.
Malaria is spread by mosquitoes and kills more than 600,000 people every year, mostly young children and pregnant women in sub-Saharan Africa. Scientists have been working for decades to develop a malaria vaccine, a complicated endeavor since the disease is caused by five different species of parasites. Worldwide, there are several dozen malaria vaccine candidates being researched.
Agenus said British drugmaker GlaxoSmithKline's candidate is the first to show in clinical studies that it can help protect young children and infants living in malaria-endemic areas. Study results were presented at a conference in Durban, South Africa.
Agenus said QS-21 Stimulon, which is derived from the bark of an evergreen tree native to central Chile, is being studied in several possible vaccines.
Shares of Agenus jumped 16.9 percent, or 47 cents, to $3.25 in premarket trading about a half-hour before the market open. The stock has traded between $2.45 and $5.40 over the past year. U.S.-traded shares of GlaxoSmithKline fell 18 cents to $49.95.