Malaria chemoprophylaxis with tafenoquine: a randomised study

Area of Science:

• Tropical Medicine
• Infectious Diseases
• Pharmacology

Background:

• Tafenoquine, a primaquine analogue, offers potential advantages in malaria chemoprophylaxis due to its long half-life and activity against liver-stage parasites.
• Assessing the efficacy and safety of tafenoquine in various dosages is crucial for its potential adoption in malaria prevention strategies.

Purpose of the Study:

• To evaluate the efficacy and safety of different doses of tafenoquine for malaria chemoprophylaxis.
• To compare the effectiveness of tafenoquine against placebo in preventing Plasmodium falciparum infections.

Main Methods:

• A randomized, double-blind study involving 426 eligible participants aged 12-20 years in Gabon, an area endemic for malaria.
• Participants received daily tafenoquine (31.25 mg to 250 mg) or placebo for 3 days, following curative treatment.
• Efficacy was assessed by monitoring positive blood smears at 56 and 77 days, with adverse events recorded throughout the 70-day follow-up.

Main Results:

• By day 77, no positive blood smears were observed in the tafenoquine 250 mg group, compared to 14 in the placebo group.
• The tafenoquine 125 mg and 62.5 mg groups showed significant reductions in positive blood smears (1 and 3, respectively) compared to placebo.
• No significant differences in the number of adverse events were reported across the treatment and placebo groups.

Conclusions:

• Tafenoquine is an effective and well-tolerated antimalarial drug.
• The findings support tafenoquine's potential to replace existing malaria chemoprophylaxis medications.
• Higher doses of tafenoquine demonstrated superior efficacy in preventing malaria infections.