Big news that could help fight a tiny foe
Most of us know what it’s like to be bitten by a mosquito. For those of us in non-malarious countries, the itchy sensation afterward is more annoying than anything, but it eventually goes away. I think it’s probably also safe to say that most people know that malaria is spread by mosquito bites. However, what’s less talked about are the different species of malaria and the need for different treatments depending on the type one has. The most deadly type of malaria is Plasmodium falciparum, and is most common in sub-Saharan Africa. However, another type—Plasmodium vivax (P. vivax)—tends to be the most difficult to cure. P. vivax malaria lives dormant in the liver and can relapse, causing malaria again anywhere between a few weeks and several months after the initial bite. It’s most prevalent in South and South East Asia, Latin America, and the horn of Africa and is responsible for 70-390 million cases of malaria per year.
You may be asking yourself, “what’s the point of me telling you all this?” At the tail end of 2013, we heard the news that an investigational antimalarial drug—tafenoquine—for the treatment and radical cure of P. vivax had completed a Phase IIb study. Tafenoquine is being developed by GHTC member Medicines for Malaria Venture (MMV)—a nonprofit working to reduce the burden of malaria by discovering, developing, and facilitating the delivery of new and effective antimalarial drugs—and the pharmaceutical company GlaxoSmithKline (GSK). The results of the Phase IIb study were published in The Lancet last December.
- The most deadly type of malaria is Plasmodium falciparum, and is most common in sub-Saharan Africa. However, another type—Plasmodium vivax (P. vivax)—tends to be the most difficult to cure. P. vivax malaria lives dormant in the liver and can relapse, causing malaria again anywhere between a few weeks and several months after the initial bite. Photo: PATH/Evelyn Hockstein
Shortly afterwards, in light of the preliminary clinical evidence and in response to GSK’s application, the US Food and Drug Administration (FDA) granted Breakthrough Therapy designation for tafenoquine. Under the designation, the FDA will work closely with the sponsors (GSK and MMV) to provide guidance to expedite the development of tafenoquine. If approved, tafenoquine offers the potential for a single dose option. However, tafenoquine still has to go through more clinical trials, and regulatory review and approval before patients are potentially able to receive treatment for P. vivax malaria. Regardless, both the completion of the Phase IIb clinical trial and it being designated FDA Breakthrough Therapy status are encouraging news that should be told.
It’s true there has been much progress in fighting malaria over the years, but hundreds of thousands of people still die each year from P. falciparum and many more suffer the subtle, chronic effects of repeated infection with P. vivax so further research efforts to tackle malaria are still required. Global health research has created lifesaving health tools that have contributed to some of the most astounding public health successes—both domestically and abroad. Research such as that being taken on by MMV and other nonprofit product developers should be supported so that new and much-needed technologies can be developed and eventually accessed by those that need them most. Research in malaria is clearly needed to develop additional tools in the arsenal against a potentially deadly mosquito bite.