The FDA approved tafenoquine (Krintafel) for the "radical cure" of Plasmodium vivax malaria in patients, ages ≥16 years, who are receiving antimalarial therapy for acute infection, .
The approval was primarily based on data from three randomized trials that tested tafenoquine in a single, 300-mg dose in over 800 individuals, and follows a strong endorsement from an FDA Advisory Committee earlier this month.
On efficacy, the Antimicrobial Drugs Advisory Committee voted unanimously (13-0) in favor of recommending approval, with one member calling the data "a slam dunk." On safety, the drug was recommended for approval with a 12-1 vote, with post-marketing studies recommended to address concerns over psychosis, anemia, and nausea.
The drug was developed by Medicines for Malaria Venture (MMV), in collaboration with GSK, as an alternative to primaquine, which is currently the only drug for relapsing malaria. Given over a 14-day period, primaquine can cause serious adverse events in some patients.
In a randomized study that compared chloroquine plus either tafenoquine or primaquine, the relapse-free efficacy rate at 6 months was similar between the two: 67.0% with tafenoquine versus 72.8% with primaquine.
"The world has waited decades for a new medicine to counter P. vivax malaria relapse. Today, we can say the wait is over," said David Reddy, PhD, chief executive officer of MMV. "Our focus is now on working to ensure the medicine reaches the vulnerable patients that need it most."
The newly approved drug is contraindicated for patients who are allergic to tafenoquine or other 8-aminoquinoline-containing agents, as well as for those who are glucose-6-phosphate dehydrogenase (G6PD) deficient. Patients should be tested if their status is unknown.
Likewise, tafenoquine should not be administered in women breastfeeding a child with G6PD deficiency or a child who has yet to be tested for it, as the drug was not tested in this setting.
, developed by 60 Degrees Pharmaceuticals with a proposed indication of malaria prevention, is currently under FDA review; the agency's Antimicrobial Drugs Advisory Committee will review that product this Thursday.