By Ben Hirschler
LONDON (Reuters) - Even as the world's first malaria vaccine gets closer to the market, two leading drug firms have joined forces to test a next-generation shot against the mosquito-borne disease that kills 800,000 people a year.
GlaxoSmithKline and Johnson & Johnson, through its newly acquired Dutch unit Crucell, plan to start a clinical trial using the so-called "prime-boost" vaccine within the next couple of months.
"If everything goes well, we would be able to start during the summer -- it's very soon," Christian Loucq, director of the PATH Malaria Vaccine Initiative (MVI) non-profit organization that is collaborating with both companies, told Reuters.
GSK's first-generation vaccine, known as RTS,S or Mosquirix, is currently in late-stage development and could reach the market in 2015. But it is only around 50 percent effective, so the hope is the next one will take things to a new level.
"This new collaboration, though in the early stages, gives us the opportunity to test an approach with the potential to substantially increase efficacy and move us closer to the internationally agreed upon goal of an 80 percent effective second-generation vaccine by 2025," Loucq said.
The new vaccine is an amended version of the current GSK shot that adds an engineered common cold virus developed by Crucell to "prime" the immune system to get a stronger response. Patients will get a single dose of Crucell's weakened virus vaccine, followed by two doses of Mosquirix.
In preclinical studies, the new approach has generated an enhanced immunity effect when compared to either vaccine component given alone.
The initial Phase I/IIa clinical trial starting this year should produce data within 18 to 24 months and, if successful, will kick-start a lengthy process of follow-up studies. This would start with a proof-of-concept Phase II trial in African adults, then one in children and finally a series of pivotal Phase III tests.
With thousands of patients needed for these later-stage studies, it is likely to be between 2020 and 2025 before GSK and J&J have a viable set of data to submit to regulators for approval.
Malaria is an infectious disease spread by mosquitoes that threatens up to half the world's population. Most of its victims are children under five in sub-Saharan Africa, making it a critical problem for poor countries but not a big money-spinning opportunity for drugmakers.
GSK Chief Executive Andrew Witty has said that if its initial vaccine proves effective it will be sold at a price that those who need it most can afford. The company is planning for a profit margin of 5 percent over the cost of making the vaccine, and has said these profits would be reinvested in new vaccines for malaria and other neglected diseases.