GlaxoSmithKline and the Medicines for Malaria Venture's (MMV) investigational malaria drug tafenoquine has been awarded 'Breakthrough Therapy' status by US regulators.

The drug, which has not been licensed anywhere in the world, is being assessed by the US Food and Drug Administration for the treatment and relapse prevention of Plasmodium vivax malaria. 

The groups note that P. vivax malaria is a neglected tropical disease and a major cause of uncomplicated malaria, which has a significant public health and economic impact primarily in South and South East Asia, Latin America and the horn of Africa, where the majority of the estimated 70-390 million annual clinical cases occur.

There is a need to provide alternative treatments to manage P. vivax relapse with shorter treatment regimens, they stress.

As an 8-aminoquinoline, Tafenoquine is of the of the same family as the current standard of care for relapse prevention primaquine. But, as this requires a 14-day treatment course, compliance is difficult to achieve in the typical treatment environment, while Tafenoquine offers a shorter treatment course (single dose) and thus could help boost adherence.

The Breakthrough Therapy designation, awarded to accelerate the development and review times of drugs for serious or life-threatening conditions, was granted to tafenoquine on the back of data from a Phase II clinical trial in more than 300 patients with uncomplicated P. vivax malaria, which showed that it was more efficacious than standard treatment with chloroquine alone, and with a similar safety profile.

Plans are underway to start a Phase III study in 2014.