The GSK and Medicines for Malaria
Venture (MMV) has announced positive results from two phase III studies of
tafenoquine, an investigational 8-aminoquinoline, for the prevention of relapse
of Plasmodium vivax (P.vivax) malaria, reports NaijaAgroNet.
The headline results, presented
today at the International Conference on Plasmodium vivax Research
(ICPVR) in Manaus, Brazil, show that a single-dose of 300mg tafenoquine, when
given with a 3-day blood-stage chloroquine treatment, reduced the risk of
relapse in patients with P.vivax malaria significantly more than placebo
when given with chloroquine.
P. vivax is one of several species of Plasmodium parasite
known to cause malaria. After an infected mosquito bite, the parasite has the
ability to lie dormant in the liver and periodically reactivate causing
relapses of P. vivax malaria. These relapses can occur weeks or even
years after the initial infection. The disease is estimated to cause around 8.5
million clinical infections every year. Each of these infections keeps a child
or adult from school or work for at least 3 days.2 Studies have
shown that beyond lost time, malaria can also have adverse effects on cognitive
ability.
Since 2008, GSK and MMV have been
working together to develop single-dose tafenoquine as an alternative to the
existing standard of care, primaquine, which must be taken for 14 days for
patients with the relapsing form of malaria. The two phase III randomised,
double-blind studies, “DETECTIVE” and “GATHER”, were conducted in
malaria-endemic countries covering South America, Asia, and Africa.