Efficacy and Safety of Fexinidazole in Patients With Stage 1 or Early Stage 2 Human African Trypanosomiasis (HAT) Due to T.b. Gambiense: a Prospective, Multicentre, Open-label Cohort Study, plug-in to the Pivotal Study

Inclusion Criteria: * Signed informed consent * 15 years old or more * Male or female * Ability to ingest at least one complete meal per day (or at least one Plumpy'Nut® sachet) * Karnofsky index \> 50 * Presence of trypanosomes in blood or lymph * Absence of trypanosomes in CSF * Permanent address and ability to comply with the follow-up visit schedule * Patient agreeing to be hospitalized to receive the treatment Exclusion Criteria: * Severely malnutrition, defined as BMI \< 16. * Inability to take oral medication. * Pregnancy or breastfeeding (a urine pregnancy test will be performed in all women of childbearing age within 24 h prior to treatment). * Clinically relevant medical condition other than HAT that, in the Investigator's opinion, may jeopardize patient safety or interfere with participation in the study, including but not limited to significant liver or cardiovascular disease, documented or suspected active infection (including AIDS), CNS trauma or seizure disorders, coma or altered consciousness. * Severely deteriorated general condition, e.g. cardiovascular shock, respiratory distress syndrome, or terminal illness. * Any medical condition (except HAT specific symptoms) hindering communication with the Investigator as required for the completion of this study. * Any contraindication to imidazole products (known hypersensitivity to imidazoles). * History of HAT treatment in the past 2 years. * Patients previously enrolled in the study or having already received fexinidazole. * Expected follow-up difficulties (migrants, refugees, itinerant vendors, etc.). * Current alcohol or drug abuse. * Clinically significant abnormal laboratory value, such as: * Alanine aminotransferase (ALAT) and/or aspartate aminotransferase (ASAT) \> 2 times ULN * Total bilirubin (TBIL) \> 1.5 times ULN * Severe leukopenia (\< 2000/mm3) * Potassium (K+) \< 3.5 mmol/L * Any clinically significant abnormal value (see details in Investigator Manual) * Pregnancy confirmed by a positive urine pregnancy test obtained within 24 h prior to start of study treatment (see Section 5.8.3 Contraception; p35) QTcF ≥ 450 ms as measured automatically (if the first measurement is abnormal, a second assessment will be done at least 10-20 min later, with the patient in resting position) * Patients not tested for malaria and/or not treated adequately for this infection * Patients not treated adequately for soil-transmitted helminthic diseases