GSK reports letdown in PhIII malaria vaccine study

In a study inspired by hope of routing malaria in African babies, GlaxoSmithKline's ($GSK) experimental vaccine failed to live up to expectations. The experimental vaccine was effective in 31% of clinical cases of malaria, showing poorer results than those seen in previous studies. Yet GSK plans to keep advancing the program, which has garnered millions of dollars in support from the Bill & Melinda Gates Foundation, according to the London-based drugmaker. 

Glaxo, which is expected to invest $500 million in developing the vaccine, doesn't have a huge amount of profit at stake in the program. But the disappointing results were unwelcome to an international effort to combat the mosquito-borne killer that was responsible for 655,000 deaths in 2010, with many of the fatalities among young children in Africa, according to the World Health Organization. Yet GSK and others are anxious nevertheless to see further analysis and data from the program.

"The efficacy came back lower than we had hoped, but developing a vaccine against a parasite is a very hard thing to do," Microsoft ($MSFT) Chairman Bill Gates, whose eponymous foundation has spent or committed billions of dollars on improving global health, said in a statement. "The trial is continuing and we look forward to getting more data to help determine whether and how to deploy this vaccine."

Glaxo partnered on the Phase III trial for the malaria vaccine, dubbed "RTS,S," with the PATH Malaria Vaccine Initiative (MVI), which is backed by $200 million in grants from the Gates Foundation. It was unimpressive to see efficacy in only a third or so of African babies who got the first dose of the vaccine at ages 6 weeks to 12 weeks, after results reported last year that showed efficacy in about half of kids ages 5 months to 17 months. Bloomberg reported that 6,537 babies were involved in the more recent study. Late-stage development of the vaccine is ongoing, according to GSK, and investigators plan to analyze the data to key in on the change in efficacy between the two age groups.

"We remain convinced that RTS,S has a role to play in tackling malaria," Glaxo CEO Andrew Witty said in a statement, "and we will continue to work with our partners and other stakeholders to better understand the data and to define how the vaccine could best be used to provide public health benefit to children in malaria endemic areas in Africa."

With plenty of further study of the vaccine ahead, GSK projects that the malaria product could hit the market by 2015.

- here's GSK's release
- see Reuters' article
- and Bloomberg's report