Acoziborole Winthrop, a new oral treatment for sleeping sickness developed by the Drugs for Neglected Diseases initiative (DNDi) and Sanofi, has received a positive opinion from the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP). The recommendation is based on results from a phase 2/3 study showing up to 96 percent success rates at 18 months in both early and advanced stages of Trypanosoma brucei gambiense sleeping sickness.
The CHMP’s positive opinion was granted through an accelerated assessment process designed for high-priority medicines intended for use outside the European Union. This step is expected to support regulatory approval in the Democratic Republic of Congo (DRC) and may lead to updates in World Health Organization (WHO) treatment guidelines, potentially expanding access across Central and West Africa where the disease remains endemic.
Acoziborole Winthrop is administered as a single dose of three tablets, offering a simpler alternative to existing treatments that require either a ten-day course of oral medication or combined injections and oral therapy. Once approved in affected countries, this could represent a significant advance over current regimens.
Sleeping sickness, also known as human African trypanosomiasis, is transmitted by tsetse flies. Without treatment, it is almost always fatal. Early symptoms include headaches and fever; if untreated, the parasite can invade the central nervous system leading to severe neurological complications and death.
“In just 20 years, we have gone from complicated treatments including arsenic derivatives with serious side effects, to today, when a single-dose, one-day therapy could safely cure patients,” said Luis Pizarro, MD, Executive Director at DNDi. “This progress is testament to the transformative power of collaborative science and will bring us closer to finally eliminating sleeping sickness, a disease that has killed millions on the African continent in the past century.”
The pivotal clinical trial supporting this decision was conducted by DNDi in partnership with national control programs in DRC and Guinea. Sanofi led regulatory activities. Results published in The Lancet Infectious Diseases showed up to 96 percent efficacy with good safety outcomes after 18 months.
“The development of acoziborole and today’s positive scientific opinion is a victory for Africa-led science, made possible thanks to African doctors and researchers who conducted cutting-edge pharmaceutical research in some of the most remote and difficult-to-reach areas on the continent,” said Erick Miaka, MD, Director of DRC’s national sleeping sickness control program.
Reported cases of gambiense sleeping sickness have dropped significantly over recent decades—from nearly 40,000 cases reported in 1998 (with an estimated 300,000 undiagnosed) to fewer than 600 cases reported globally in 2024. Earlier treatments included injectable arsenic derivatives with serious side effects; subsequent advances included combination therapies such as NECT (nifurtimox-eflornithine) introduced in 2009 and fexinidazole—the first all-oral treatment—approved in 2018.
“For decades, Sanofi has maintained an unwavering commitment to the fight against sleeping sickness, standing alongside DNDi, the World Health Organization, and other partners in one of the most enduring and successful public-private health collaborations,” said Audrey Duval, Executive Vice President, Corporate Affairs at Sanofi. “Together, we have helped drive cases to historic lows—achieving a remarkable 98% reduction since 2001—by putting patients first and investing in innovation where it is needed most. Acoziborole builds on this legacy and represents a decisive step forward in eliminating gambiense sleeping sickness by 2030.”
Sanofi will donate Acoziborole Winthrop free-of-charge through its philanthropic arm Foundation S – The Sanofi Collective – making it available via WHO distribution channels.
Research continues into using Acoziborole Winthrop for children aged one to fourteen years old through ongoing studies in DRC and Guinea.
The development program for Acoziborole Winthrop involved support from multiple international agencies including Germany’s Federal Ministry of Research through KfW; BBVA Foundation; Dutch Ministry of Foreign Affairs; European Union-supported partnerships; Gates Foundation; Médecins Sans Frontières International; Norwegian government agencies; Swiss government entities; Stavros Niarchos Foundation; Spanish Agency for International Development Cooperation; UK International Development; among others.
Acoziborole Winthrop originated from research involving Anacor Pharmaceuticals’ chemical library before being optimized with Scynexis and Pace University. It underwent initial safety studies successfully completed in France, UK, and Malaysia prior to selection as a candidate drug.
DNDi describes itself as a not-for-profit medical research organization focused on developing treatments for neglected diseases affecting vulnerable populations worldwide. Since its founding in 2003 it has delivered new therapies for six deadly diseases—including leishmaniasis and Chagas disease—and counts Acoziborole as its fourteenth treatment delivered.
Sanofi is described as an R&D-driven biopharmaceutical company leveraging artificial intelligence technologies with products distributed globally. The company trades publicly on EURONEXT: SAN and NASDAQ: SNY.
