New guidance issued by the CDC offers details on the dosing, efficacy and safety of tafenoquine for prevention and antirelapse therapy for malaria.
The US Centers for Disease Control and Prevention has issued new guidance for using tafenoquine to treat and prevent malaria with a simplified dosing schedule that could help improve adherence.
Malaria continues to be a serious global health threat, with more than 219 million cases worldwide in 2017 causing about 435,000 deaths.
“Tafenoquine is a new safe and effective drug that can be used to prevent malaria, and, when given with another drug, can be used to treat certain types of malaria,” Kathrine Tan, MD, MPH, medical officer, Division of Parasitic Diseases and Malaria, US Centers for Disease Control and Prevention, Center for Global Health, told Contagion®. “Also, tafenoquine has simplified dosing regimens that have the potential to make it easier for people to complete treatment. This guidance provides information on efficacy, safety, and dosing of tafenoquine.”
Last year, the US Food and Drug Administration approved tafenoquine for prevention and antirelapse therapy for malaria as the first new drug approved to treat the mosquito-borne condition in 60 years. It is a long-acting 8-aminoquinoline drug related to primaquine.
“Travelers have an additional safe and effective option to prevent malaria,” Tan told Contagion®. “This drug has a simplified dosing regimen that makes it appropriate for many last-minute travelers, and the dosing may make it easier to remember to take all of the pills.”
Adults aged 18 years and older traveling to countries with malaria transmission, can use Arakoda (100 mg tafenoquine tablets) for chemoprophylaxis for all species of malaria in doses of 200 mg for 3 days before the travel, 200 mg weekly during travel, and 200 mg after returning, according to the guidance.
Unlike most drugs approved for malaria, which only affect the blood stage of the pathogen, tafenoquine kills both the blood and liver stages, including the dormant hypnozoites in the liver that cause relapse in Plasmodium vivax and P ovale species of the parasite.
Krintafel, (150 mg tafenoquine tablets) can be used for antirelapse therapy for the P vivax species of malaria among people ages 16 years and older in a single 300 mg dose in combination with blood-stage treatment or prophylaxis. It also can be used off-label for P ovale.
“Two kinds of malaria have parasites that can hide in the liver, only to emerge later to cause disease,” Tan told Contagion®. “Most antimalarial drugs don’t kill these hidden parasites. Tafenoquine is only the second drug that can kill these liver parasites. Tafenoquine also has a simplified dosing regimen that has the potential to make it easier for people to complete treatment.”
Testing for glucose-6-phosphate dehydrogenase (G6PD) deficiency is required before prescribing tafenoquine because the drug, like primaquine, causes hemolysis in people with G6PD deficiency.
Earlier this year, a study supported by GlaxoSmithKline found that the risk of P vivax malaria recurring was about 70% lower with tafenoquine than with a placebo.
Meanwhile, a pilot for a malaria vaccine, known as RTS,S, is under way in Kenya, Ghana and Malawi.