Determination of the Optimal Single Dose Treatment for Acoziborole, a Novel Drug for the Treatment of Human African Trypanosomiasis: First-in-Human Study.

Background And Objectives: Acoziborole is a novel boron-containing candidate developed as an oral drug for the treatment of human African trypanosomiasis (HAT). Results from preclinical studies allowed progression to Phase 1 trials. We aimed to determine the best dose regimen for all stages of HAT.

Methods: Acoziborole was assessed in 128 healthy adult males of sub-Saharan African origin living in France. The study included a single oral administration of a 20- to 1200-mg dose in a randomised double-blind study in cohorts of 8 (6 active, 2 placebo) to assess safety, tolerability, and pharmacokinetics. In three additional open cohorts of 6 participants, the effect of activated charcoal was evaluated, bioequivalence of capsules versus tablets was assessed, and safety in the 960-mg tablet cohorts was monitored.

Results: Acoziborole was well tolerated at all doses tested; no dose-related adverse events were observed. The drug appeared rapidly in plasma (at 1 h), reached t between 24 and 72 h, and remained stable for up to 96 h, after which a slow decrease was quantifiable until 14 weeks after dosing. Charcoal had little impact on the enterohepatic recirculation effect, except for the 20-mg dose. Bioequivalence between capsule and tablet formulations was demonstrated. The therapeutic single dose for administration under fasted conditions was fixed to 960 mg. The maximum administered dose was 1200 mg.

Conclusions: This study showed that acoziborole could be safely assessed in patients as a potential single-dose oral cure for both stages of gambiense HAT.

Trial Registration: The study was registered with ClinicalTrials.gov: NCT01533961.