FDA approves new drug for treatment of malaria

A new drug to treat malaria could help millions.

The Food and Drug Administration has approved the drug Krintafel (tafenoquine) for the treatment of malaria following a Priority Review this past Friday.

The drug, developed by GSK Pharmaceuticals and Medicines for Malaria Venture, is a single dose medication designed for people who've had malaria before. It prevents the relapse of malaria caused by Plasmodium vivax (P.vivax).

P.vivax is one of several parasites in the Plasmodium family known to cause malaria. It accounts for infection with malaria in 15-20% of the cases around the world; that's roughly 8.5 million infections per year.

Unlike its cousin Plasmodium falciparum, which is responsible for approximately 75% of the cases, following the initial infection in the blood, P. vivax can go into a dormant stage in the liver, where most anti-malaria medications cannot reach it.

Currently, patients with P.vivax require a 10 day treatment with the drug Primaquine to eradicate those dormant liver parasites. Many patients, much to the frustration of doctors, do not complete all 10 days of treatment, leading to the survival of the parasite and the recurrence of malaria.

Krintafel, approved this past Friday, eradicates dormant P.vivax parasites after one dose.

Dr. David Reddy, Chief Executive Officer of Medicines for Malaria Venture said in a press release, “The US FDA’s approval of Krintafel is a major milestone and a significant contribution towards global efforts to eradicate malaria. The world has waited decades for a new medicine to counter P. vivax malaria relapse. Today, we can say the wait is over. Moreover, as the first ever single-dose for this indication, Krintafel will help improve patient compliance. We are proud to have worked side-by-side with GSK for more than a decade to reach this point. Our focus is now on working to ensure the medicine reaches the vulnerable patients that need it most.”

The efficacy and safety of the drug were established in two large randomized studies published in the summer of 2017. Manufacturers do warn patients with a deficiency in an enzyme in red blood cells known as G6PD, women breastfeeding a child with G6PD deficiency, or anyone who has not been tested for this condition, should not take Krintafel due to the risk for worsening anemia.

In an interview with ABC news, Dr. Regina Rabinovich, President of the American Society of Tropical Medicine and Hygiene (ASTMH) and ExxonMobil Malaria Scholar in Residence at Harvard University, extended her congratulations to the team involved in this effort, because they are "addressing a part of the burden of malaria often neglected by the global agenda. P vivax used to be thought of as benign, but it is not benign.”

So does this medication complete what doctors need in the global efforts against malaria? Dr. Rabinovich says “There is no silver bullet in malaria.” She speaks to the importance of a multi-faceted approach- “We need basic prevention technologies, surveillance and reporting, really good health systems, and surveillance response. You have to be able to do something to help once you identify a problem.”

According to the 2017 report from the World Health Organization, in 2016 there were an estimated 216 million cases of malaria, an increase of about 5 million cases over 2015, warning that previous advances and efforts have stalled.

Dr. Rabinovich worries the 2018 report, which will be released later this year, might be even worse, in part due to decreased global funding for malaria prevention.

Dr. Edith Bracho-Sanchez is a pediatrician working with the ABC Medical Unit.