For over a century, treating sleeping sickness — African trypanosomiasis — required either arsenic-based drugs that killed 5% of patients, or multi-day intravenous infusions in hospitals that barely exist in affected regions. The disease crosses the blood-brain barrier, which made oral treatment seem pharmacologically impossible: any drug that could reach the parasites in the central nervous system would need to cross the same barrier, at therapeutic concentrations, from a pill.
Acoziborole, developed by the Drugs for Neglected Diseases initiative and Sanofi, received a positive opinion from the European Medicines Agency in February 2026 as a three-tablet, single-dose oral treatment for both early and advanced-stage gambiense sleeping sickness. Phase 2/3 trials showed success rates up to 96% at 18 months. Sanofi has pledged to donate all doses to the WHO. The drug will be free to patients.
The structural insight is about the relationship between pharmacological barriers and logistical barriers. The blood-brain barrier was the scientific problem — could a small molecule cross it at sufficient concentration from an oral dose? But the logistical barrier was equally constraining: the disease occurs in remote regions of Central and West Africa where multi-day hospitalization with IV infusion is functionally impossible for most patients. Solving the pharmacological problem without solving the logistical problem would have produced a drug that works but cannot be delivered. A single oral dose solves both simultaneously. The three pills are not just a convenient formulation — they are the difference between a treatment that exists and a treatment that reaches patients.
A disease that required weeks of hospitalization and toxic intravenous drugs now requires swallowing three pills on one occasion. The path to eradication is now logistically feasible because the last barrier was not the blood-brain barrier — it was the hospital door.