The FDA recently approved Krintafel for the prevention of Plasmodium vivax malaria relapse in patients aged 16 years or older.
Krintafel (tafenoquine, GlaxoSmithKline) is a single-dose medication available for those who have been administered the recommended antimalarial therapy for acute infection. The drug was developed through a partnership between GSK and the Medicines for Malaria Venture (MMV).
“Vivax malaria is an underrecognized type of malaria but is widely seen in the Americas and Asia-Pacific,” Regina Rabinovich, MD, MPH, president of the American Society of Tropical Medicine and Hygiene, told Infectious Diseases in Children. “What it takes to treat this type of malaria is usually one drug to treat the parasite in the blood and a second to get the parasite where it goes dormant — the liver — only to reemerge weeks or months later. Tafenoquine is a single-dose drug, which makes it far easier to effectively get rid of the parasite in the liver. With such a simple regimen, it is easier to get to rural or mobile populations and attack this infection.”
The approval of tafenoquine was based primarily on the results of 13 efficacy and safety studies. These studies included both healthy volunteers and patients with malaria. According to GSK, the most compelling evidence for the drug’s efficacy and safety was observed in three randomized, double-blind phase 3 studies, in which one dose of the drug — containing 300 mg of tafenoquine — was administered to more than 800 participants. However, the submission included data from 33 studies and more than 4,000 participants.
Additionally, GSK has been awarded a tropical disease priority review voucher by the FDA. This program was developed to promote the development of drugs and biological products to treat and prevent neglected tropical diseases around the world.
“The U.S. FDA’s approval of [tafenoquine] is a major milestone and a significant contribution toward global efforts to eradicate malaria,” David Reddy, PhD, MSc, CEO of MMV, said in a press release. “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 the indication, [tafenoquine] will help improve patient compliance… Our focus is now on working to ensure the medicine reaches the vulnerable patients that need it most.”
Tafenoquine is currently being reviewed by the Australian Therapeutic Goods Administration (TGA). GSK stated that approvals from the FDA and TGA may be useful for regulatory agencies in other parts of the world where malaria is endemic that have their own drug-approval processes. According to the company, they plan to provide tafenoquine to these countries as a not-for-profit medicine to improve access to the medication.
“Having a regulatory group like the U.S. FDA review and approve this new drug facilitates rapid access for people living in endemic countries as well as people in the U.S. who may have become infected with P. vivax malaria while abroad,” Rabinovich said.
Disclosure: Rabinovich reports no relevant financial disclosures.