Phase 2 RCT: Preventive subcutaneous L9LS monoclonal antibody reduces malaria incidence by 66-70% in Malian children – N Engl J Med

This phase 2 randomized clinical trial investigated the safety and efficacy of the monoclonal antibody L9LS in preventing Plasmodium falciparum infection and clinical malaria in children aged 6 to 10 years in Mali. The trial was structured in two parts: initial dose assessment in adults followed by a randomized, placebo-controlled test in children over a 6-month malaria season. A total of 225 children participated, divided equally among three groups to receive either 150 mg of L9LS, 300 mg of L9LS, or a placebo. Results demonstrated a significant reduction in the rate of P. falciparum infection—66% efficacy with the 150-mg dose and 70% efficacy with the 300-mg dose. Similarly, efficacy against clinical malaria was 67% with the 150-mg dose and 77% with the 300-mg dose. Both doses were well-tolerated with no safety concerns reported, underscoring the potential of L9LS as a preventative treatment against malaria in endemic regions.

Reference (link to abstract – $ for full-text):

Kayentao, K. et al. (2024). Subcutaneous Administration of a Monoclonal Antibody to Prevent Malaria. N Engl J Med, 390(17), 1549-1559. DOI: 10.1056/NEJMoa2312775