EMA Backs Single-Dose Oral Treatment for Sleeping Sickness – Acoziborole Winthrop

Kinshasa / Paris / Geneva / Amsterdam – A significant step toward eliminating sleeping sickness has been achieved with the European Medicines Agency’s (CHMP) positive opinion for Acoziborole Winthrop, a single-dose oral treatment developed by the Drugs for Neglected Diseases initiative (DNDi) and Sanofi. The recommendation, issued on February 27, 2026, paves the way for approval in the Democratic Republic of Congo (DRC) and potential updates to World Health Organization (WHO) treatment guidelines, offering a simpler and more effective alternative to existing therapies for the most common form of the disease, Trypanosoma brucei gambiense (g-HAT).

The CHMP’s endorsement is based on a Phase II/III study demonstrating up to 96 percent success rates at 18 months across both early and advanced stages of g-HAT. This represents a major advancement in the fight against a disease that, without treatment, is almost always fatal. The treatment consists of a single dose of three tablets, a significant simplification compared to current regimens that require either a 10-day course of oral medication or a combination of injections and oral therapy.

A Collaborative Effort Yields Breakthrough Results

The development of Acoziborole Winthrop is a testament to the power of collaborative science. DNDi, a not-for-profit medical research organization focused on neglected diseases, partnered with pharmaceutical giant Sanofi to bring this new treatment to fruition. Sanofi will donate the medicine to the WHO through its philanthropic arm, Foundation S, ensuring free access to patients in endemic countries. This donation program builds on previous successful initiatives, such as the one established with Bayer to provide nifurtimox-eflornithine combination therapy (NECT) free of charge through the WHO, dramatically improving treatment options for sleeping sickness patients.

“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 Dr. Luis Pizarro, Executive Director at DNDi. This progress, he emphasized, is a “testament to the transformative power of collaborative science” and will bring the world closer to eliminating sleeping sickness by 2030.

Understanding Human African Trypanosomiasis

Human African trypanosomiasis, commonly known as sleeping sickness, is transmitted by the bite of an infected tsetse fly. The disease progresses in stages. Initially, symptoms can be vague, including headaches and fever. However, as the parasite crosses the blood-brain barrier and invades the central nervous system, more severe neurological and behavioral symptoms emerge, such as seizures, sleep disturbance, aggression, confusion, and death. Without treatment, the prognosis is grim.

The disease is endemic to several countries in Central and West Africa. In 1998, nearly 40,000 cases of g-HAT were reported, with an estimated 300,000 undiagnosed. Decades of investment in research and development have led to increasingly effective treatments, including NECT in 2009 and fexinidazole, the first all-oral treatment, in 2018. These efforts have resulted in a dramatic reduction in cases, with fewer than 600 reported in 2024.

The Regulatory Pathway and Accelerated Assessment

The CHMP positive opinion was granted through an accelerated assessment procedure specifically designed for medicines addressing unmet needs in countries outside the European Union. This pathway, known as EU-M4all, involves collaboration with WHO disease experts and regulators from endemic countries, ensuring that the medicine meets international standards and is tailored to the specific needs of affected populations. The positive opinion will facilitate regulatory approval in the DRC and is expected to inform updates to the WHO’s sleeping sickness treatment guidelines, potentially expanding access to the treatment across Central and West Africa.

Acoziborole Winthrop is available as 320 mg tablets. The active substance, acoziborole, is an antiprotozoal that appears to inhibit the maturation of T. Brucei messenger ribonucleic acid (mRNA) by binding to cleavage and polyadenylation specificity factor 3 (CPSF3). The boron atom within the molecule is believed to be crucial for its trypanocidal activity, though the precise mechanisms are still being investigated. Clinical trials have demonstrated high efficacy, with success rates of around 95.2% in patients with second-stage disease and 100% in those with first- and intermediate-stage g-HAT after 18 months. Common side effects observed during trials included pyrexia, asthenia, decreased appetite, tremor, and headache.

African Leadership and Local Production

The development and success of Acoziborole Winthrop are being hailed as a victory for African-led science. Dr. Erick Miaka, Director of the DRC’s national sleeping sickness control programme, emphasized that the breakthrough was made possible by African doctors and researchers conducting cutting-edge pharmaceutical research in challenging environments. There is growing momentum to explore local production of treatments like acoziborole in Africa, strengthening pharmaceutical manufacturing capacity and supply chain resilience across the continent. The Africa Centres for Disease Control and Prevention (Africa CDC) is actively supporting these efforts, aligning with its broader drive to expand local production capacity.

As stated by Director General of Africa CDC, H.E. Dr. Jean Kaseya, “This breakthrough brings Africa closer to eliminating sleeping sickness and reflects the growing strength of African scientific leadership.”

What Remains Unclear and What Happens Next

While the CHMP positive opinion is a major milestone, several steps remain before Acoziborole Winthrop becomes widely available. The DRC’s national regulatory authority must now formally approve the medicine for use within the country. Following DRC approval, the WHO will review the data and consider updating its treatment guidelines to include acoziborole. This process typically involves consultations with experts and stakeholders from endemic countries.

Currently, a separate study is underway in the DRC and Guinea to investigate the efficacy and safety of Acoziborole Winthrop in children aged 1 to 14. The results of this study will be crucial in determining whether the treatment can be extended to younger populations.

The long-term impact of Acoziborole Winthrop on sleeping sickness elimination efforts will depend on several factors, including sustained funding for control programs, effective surveillance systems, and continued collaboration between international organizations, governments, and local communities. However, the availability of a single-dose, highly effective oral treatment represents a significant leap forward in the fight against this neglected tropical disease.

Looking Ahead: Strengthening Regional Capacity

Beyond treatment, bolstering regional capacity for diagnosis and surveillance will be critical. The Africa CDC’s focus on strengthening laboratory networks and training healthcare workers will play a vital role in ensuring that cases are detected early and treated promptly. Continued investment in vector control measures, such as tsetse fly trapping and insecticide-treated nets, will be essential to interrupt the transmission cycle and prevent resurgence of the disease. The success of Acoziborole Winthrop, is not merely a pharmaceutical achievement, but a catalyst for broader improvements in public health infrastructure and disease control systems across affected regions.