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DNDi Achievements

Fexinidazole to treat sleeping sickness Sleeping sickness

First new chemical entity developed by DNDi and the first all-oral cure for all stages of sleeping sickness



Easy-to-use medicine brings treatment closer to patients

NECT, a combination of nifurtimox and eflornithine, was approved for sleeping sickness in 2009, replacing very toxic or complicated drugs. But treatment remained cumbersome, difficult to ship, store, and administer; patients needed to be hospitalized to receive the intravenous infusions and undergo a lumbar puncture to determine the stage of the disease since NECT is only indicated for stage-2.

DNDi, in collaboration with the Swiss Tropical and Public Health, rediscovered the 5-nitroimidazole derivative fexinidazole during a search for compounds with anti-parasitic activity in 2005. The compound had been developed but abandoned for strategic reasons by Hoechst (now Sanofi) in the 1980s. In 2009, DNDi and Sanofi concluded a collaboration agreement.

More than two million people were screened for sleeping sickness as part of three fexinidazole clinical trials, which enrolled 749 patients in the Democratic Republic of Congo and Central African Republic and had to overcome unique challenges of conducting trials in remote areas where sleeping sickness occurs. In the trials, fexinidazole showed high efficacy and safety in both stages of the disease, both in adults and children.  

Fexinidazole is the first all-oral treatment for both stages of T. b. gambiense sleeping sickness, the most common form of the disease. Taken as simple pills for 10 days, fexinidazole presents significant advantages over NECT because it eliminates the need for systematic hospitalization and potentially leads to a reduction in the number of lumbar punctures. The European Medicines Agency adopted a positive scientific opinion of fexinidazole in late 2018, paving the way for registration and distribution in endemic countries.

Fexinidazole is the first new chemical entity to have been developed by DNDi, which has steered its progression through all stages of the drug development pipeline from lab to patient.


At a glance

  • Indication: stage-1 and stage-2 gambiense sleeping sickness (human African trypanosomiasis)
  • Dosage: 
    Adults: 3 tablets once-a-day for 4 days, and 2 tablets once-a-day for next 6 days
    Children (≥ 6 years old & ≥ 20 kg): 2 tablets once-a-day for 4 days, and 1 tablet once-a-day for next 6 days
  • Project start: 2005
  • Project cost: EUR 55 million (2005-2018)*

Fexinidazole pill in a hand


  • Recommended in November 2018 by the European Medicines Agency under Article 58, an innovative regulatory mechanism for the review of new medicines destined for use outside of the European Union
  • Approved in the Democratic Republic of Congo in 2019
  • Registration submission in other endemic countries underway
  • Sanofi has committed to donate fexinidazole to WHO, which will distribute it to National Control Programmes in endemic countries
  • Developed in partnership between DNDi, Sanofi, the HAT Platform, national control programmes of the Democratic Republic of the Congo and Central African Republic, Médecins Sans Frontières, Swiss Tropical & Public Health Institute, with support of the World Health Organization, Department of Control of Neglected Tropical Diseases


“Those affected by sleeping sickness are some of the most vulnerable and live in some of the most remote areas of the Congo, if not the world. They need a treatment that is safe, effective and simple. An all-oral treatment has been a dream of mine for decades. Fexinidazole is a huge leap in how we can tackle this deadly disease.”

Dr Victor Kande, NTD Expert Advisor to the Ministry of Health of DRC and principal investigator of the fexinidazole clinical trials

Key scientific articles

Oral fexinidazole for late-stage African Trypanosoma brucei gambiense trypanosomiasis: a pivotal multicentre, randomised, non-inferiority trial. The Lancet, November 2017
by Kande Betu Ku Mesu V, Mutombo Kalonji W, Bardonneau C, Valverde Mordt O, Blesson S, Simon F, Delhomme S, Bernhard S, Kuziena W, Fina Lubaki JP, Lumeya Vuvu S, Nganzobo Ngima P, Mahenzi Mbembo H, Ilunga M, Kasongo Bonama A, Amici Heradi J, Lumaliza Solomo JL, Mandula G, Kaninda Badibabi L, Regongbenga Dama F, Kavunga Lukula P, Ngolo Tete D, Lumbala C, Scherrer B, Strub-Wourgaft N, Tarral A.

Determination of an optimal dosing regimen for fexinidazole, a novel oral drug for the treatment of human African trypanosomiasis: First-in-human studies. Clinical Pharmacokinetics, February 2014
by Tarral A, Blesson S, Valverde Mordt O, Torreele E, Sassella D, Bray MA, Hovsepian L, Evène E, Gualano V, Felices M, Strub-Wourgaft N.

Genotoxicity profile of fexinidazole – a drug candidate in clinical development for human African trypanomiasis (sleeping sickness). Mutagenesis, September 2012
by Tweats D, Bourdin Trunz B, Torreele E.

Antitrypanosomal activity of fexinidazole, a new oral nitroimidazole drug candidate for treatment of sleeping sickness. Antimicrob Agents Chemother, December 2011
by Kaiser M, Bray MA, Cal M, Bourdin Trunz B, Torreele E, and Brun R.

Fexinidazole – A new oral nitroimidazole drug candidate entering clinical development for the treatment of sleeping sickness. PLOS Neglected Tropical Diseases, December 2010
by Torreele E, Bourdin Trunz B, Tweats D, Kaiser M, Brun R, Mazué G, Bray M A, Pécoul B.

News and press releases



Accelera, Italy; Amatsi Aquitaine (formerly Bertin Pharma), France; Aptuit, Italy; BaseCon A/S, Denmark; Biotrial, France; Bruno Scherrer, France; Bureau d’Etude Ingénierie – Ste Dina Sarl, Guinea; Cardiabase, France; CBCO, DRC; Centipharm, France; Drugabilis, France; Institute of Tropical Medicine Antwerp, Belgium; Institut de Recherche pour le Développement, France; Institut National de Recherche Biomédicale, DRC; HAT Platform; Médecins Sans Frontières; National Control Programmes of the Democratic Republic of Congo, the Central African Republic, and Guinea; Phinc, France; Sanofi, France; SGS, Belgium; SGS, France; Swiss Tropical and Public Health Institute, Switzerland; WHO Department of Control of Neglected Tropical Diseases, Switzerland.


Bill & Melinda Gates Foundation, USA; UK aid, UK; Dutch Ministry of Foreign Affairs (DGIS), The Netherlands; Federal Ministry of Education and Research (BMBF) through KfW, Germany; French Development Agency (AFD), France; German Corporation for International Cooperation (GIZ) on behalf of the Government of the Federal Republic of Germany, Germany; Ministry for Europe and Foreign Affairs, France, Médecins sans Frontières; Norwegian Agency for Development Cooperation (Norad), Norway; Republic and Canton of Geneva, Internal Solidarity Service, Switzerland; Spanish Agency for International Development and Cooperation (AECID), Spain; Swiss Agency for Development and Cooperation (SDC), Switzerland; UBS Optimus Foundation, Switzerland; Brian Mercer Charitable Trust, UK; Stavros Niarchos Foundation, USA and other private foundations and individuals from the HAT campaign.



*From 2005 to 2018, DNDi invested EUR 55 million for the full development of fexinidazole from discovery to clinical trials development (except the Phase IIIb trial that started in 2016 to obtain more information about special populations not included in previous fexinidazole trials). Project cost includes direct and indirect costs, but it does not include in-kind contributions. As of December 2018, Sanofi estimates an overall contribution of EUR 13 million (including regulatory, human resources, industrial activities, etc.).

Photo credit: Xavier Vahed-DNDi

Last updated: January 2019