New benznidazole regimens
New benznidazole regimens
Evaluate new therapeutic regimens of benznidazole as monotherapy, or in combination with fosravuconazole, for the treatment of adult patients with chronic Chagas disease.
current phase of drug development




Benznidazole, currently the standard treatment and the best option for people with Chagas disease, is effective but has limitations: the treatment lasts 60 days, and some 20% of patients stop treatment due to side effects, which can include skin rashes, gastric intolerance, and neuromuscular problems. To improve adherence to treatment, DNDi and partners decided to test the efficacy of new regimens where exposure to benznidazole would be reduced, either due to shorter treatment, lower doses, or both.
In 2013, a proof-of-concept trial showed that fosravuconazole, an azole-class antifungal drug discovered by Eisai Ltd (Japan), had good safety and was effective at clearing the parasite, but efficacy was not sustained. A Phase I drug-drug interaction study assessed the safety and pharmacokinetic interactions of fosravuconazole and benznidazole administered separately and in combination. No major clinically relevant safety or tolerability issues were identified.
The BENDITA (Benznidazole New Doses Improved Treatment & Therapeutic Associations) study looked for regimens at least as effective as the standard treatment, with fewer side effects. From 2016 to 2018, a Phase II, randomized, placebo-controlled study was carried out in three sites in Bolivia to test six benznidazole treatments of differing lengths and dosages, both as a monotherapy and in combination with fosravuconazole, against a placebo. The aim was to improve efficacy, safety, and tolerability of treatment of adults with chronic indeterminate Chagas disease, thereby improving patients’ adherence and making the treatment more acceptable to physicians.
Results showed that the new regimens’ main benefits were related to an improved safety profile, as well as a better adherence, but further assessment was required to confirm non-inferiority compared to standard regimens. DNDi continues to work with national programmes, partners, and health ministries of endemic countries to confirm these results and encourage the necessary steps to register the new regimen. In 2023, DNDi started a Phase III clinical trial in Argentina to validate a two-week and four-week regimen with benznidazole for adults in the chronic phase of the disease.
Project updates
2024
The NuestroBen study continued recruitment at six sites in Argentina (four in Buenos Aires and two in the north of the country), and recruitment of a total of 300 participants is expected by the end of 2025. At least one study site in Bolivia is expected to open in the first quarter of 2025.
The reanalysis of the BENDITA study based on individual patient data was completed, and the results and findings on healthcare provider acceptability of the shorter regimens will be published in early 2025.
2023
Working together with partners Mundo Sano Foundation and Laboratorio ELEA-Phoenix in Argentina, the NuestroBen study was reinitiated in the second quarter of 2023 following receipt of ethical and regulatory approvals and preparation of study sites. The first participant entered the study in August in accordance with the revised study protocol. Four study sites were opened by the end of the year in Buenos Aires and northern Argentina. A total of 300 participants are expected to be recruited by the first quarter of 2025.
2022
Based on new evidence from post-hoc analyses of the BENDITA study, the NuestroBen study was redesigned. The primary objective will be to compare the safety and efficacy of 2-week and 4-week regimens, versus the 8-week standard regimen, in adults in the chronic phase of Chagas disease of indeterminate form or with mild cardiac progression.
Together with partners Mundo Sano Foundation and Laboratorio Elea Phoenix in Argentina, DNDi reviewed the current clinical research landscape for Chagas and the suitability of short regimens of benznidazole. An agenda was developed in collaboration with the scientific community and lead statisticians to evaluate potential options for the study design of the Phase III clinical trial in Argentina. The updated study design was developed through a technical-scientific collaboration with Fiocruz – which leads a Phase III trial in Colombia and Bolivia with a similar approach – with the aim of harmonizing efficacy results across the Phase III trials. Ethical/regulatory submissions are expected by end of the first quarter 2023.
2021
In conjunction with partners Mundo Sano Foundation and Laboratorio Elea Phoenix in Argentina, DNDi embarked on Phase III study to compare the safety and efficacy of a two-week treatment regimen of benznidazole to the current standard eight-week treatment. After obtaining all ethical and regulatory approvals, the study was initiated in July 2021. DNDi also began contributing as a key collaborator in a Fiocruz-led Phase III study of a short-course benznidazole treatment regimen in Colombia, Bolivia, and Brazil, as part of a Unitaid-funded project to interrupt congenital transmission of Chagas disease. This study is currently being reviewed by the relevant ethical committees.
In April 2021, a manuscript on the earlier BENDITA study was published in The Lancet Infectious Diseases.
2020
BENDITA, the first Phase II study of new treatment regimens of benznidazole, was finalized and a manuscript describing the results was accepted for publication in Lancet Infectious Diseases. The results, indicating good efficacy and safety in shorter regimens of benznidazole and combination therapies with fosravuconazole, supported a strategy to validate a shortened treatment regimen in a Phase III clinical trial.
DNDi began leading, in conjunction with partners Mundo Sano Foundation and ELEA, a Phase III study to compare the efficacy and safety of a 2-week treatment of benznidazole compared to the current standard (an 8-week treatment). The study will take place in Argentina and begin recruitment in mid-2021.
The positive BENDITA results also provided the basis for a wider regional initiative with funding support from Unitaid to interrupt congenital transmission of Chagas disease; DNDi actively participated in the construction, along with Fiocruz, FIND, and other partners. The initiative will include a Phase III study of a short treatment of benznidazole in Colombia, Bolivia, and Brazil, which will help answer the question of whether a shortened treatment can be effective in different areas with different T. cruzi strains. DNDi is a key collaborator in the Fiocruz-led initiative.
2019
Phase II trial results available in early 2019 showed that all treatment arms were effective compared to placebo and the new regimens presented good safety profiles. The two-week course of treatment with benznidazole monotherapy was particularly promising. While significantly shorter than the standard eight-week treatment, it showed 83% efficacy and none of the patients assigned to this arm had to discontinue treatment due to side effects. Based on these results, DNDi is planning to run an international, multi-site confirmatory Phase III study.
2018
This proof-of-concept trial was completed in the third quarter of 2018 and results will be available in early 2019. A total of 210 patients were recruited for this study, which was conducted in three sites in Bolivia and aims to improve efficacy, safety and tolerability of treatment of adults with chronic indeterminate Chagas. The trial assessed the efficacy of different doses of benznidazole in monotherapy and in combination with fosravuconazole. The primary measure of efficacy is a sustained parasitological response at six months follow-up with a final assessment at 12 months.
2017
The trial is being conducted in three sites in Bolivia, with recruitment completed in late 2017. The primary efficacy parameter is sustained parasitological response at six months. The final assessment will include 12 months of follow-up, with final results available in early 2019.
2016
Regulatory approvals were secured in Bolivia to start a Phase II Proof of Concept (PoC) study to determine if the safety (known as the “BENDITA” study) and tolerability issues of benznidazole could be managed by reduced doses and treatment duration, or by combining it with fosravuconazole. Benznidazole in monotherapy or in combination with fosravuconazole at selected doses and treatment durations will be assessed versus placebo in 210 patients with chronic Chagas disease. Recruitment started at the end of November; 10 patients had been enrolled by the end of 2016.
News & resources
- 3 December 2024 - Early assessment of antibodies decline in Chagas patients following treatment using a serological multiplex immunoassay, Nature Communications
- 14 April 2021 - Un medicamento en Fase II para la enfermedad de Chagas podría darse sólo dos semanas y ayudar a más pacientes, Infobae
- 7 April 2021 - Confirman la efectividad del tratamiento breve en la enfermedad de Chagas, Estrella digital
- 6 April 2021 - Chagas disease: Shorter treatment just as effective as longer one, according to study in Bolivia published by The Lancet
- 14 March 2019 - Study shows dramatically shorter treatment for Chagas disease could be just as effective, and significantly safer
- Centro de Enfermedad de Chagas y Patologia Regional Hospital Independencia, Argentina
- Collective of Applied Studies and Social Development (CEADES), Bolivia
- Eisai Co., Ltd., Japan
- FP Clinical Pharma – Ethel Feleder, Argentina
- Fundacio Investigacio Hospital General Valencia, Spain
- Fundación Huésped, Argentina
- Fundación Mundo Sano, Argentina
- Hospital Donación Francisco Santojanni, Argentina
- Hospital Francisco Javier Muñiz, Argentina
- Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
- INP Dr. Mario Fatala Cháben, Argentina
- ISGlobal, Barcelona Institute for Global Health, Spain
- Instituto de Cardiología de Corrientes, Argentina
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Argentina
- Laboratorio Elea Phoenix S.A., Argentina
- Luxembourg Institute of Health, Luxembourg
- Ministry of Health (Bolivia), Bolivia
- Ministry of Health Argentina, Argentina
- Núcleo de Desenvolvimento Farmacêutico e Cosmético (NUDFAC), Brazil
- Oswaldo Cruz Foundation – Fiocruz, Brazil
- Platforms of Integral Care for Patients with Chagas Disease, Bolivia
- Universidad Autónoma Juan Misael Saracho, Bolivia
- Universidad Mayor de San Simon, Bolivia
- Vall d’Hebron University Hospital, Spain
- Centro de Enfermedad de Chagas y Patologia Regional Hospital Independencia
- ,Argentina
- Collective of Applied Studies and Social Development (CEADES)
- ,Bolivia
- Eisai Co., Ltd.
- ,Japan
- FP Clinical Pharma – Ethel Feleder
- ,Argentina
- Fundacio Investigacio Hospital General Valencia
- ,Spain
- Fundación Huésped
- ,Argentina
- Fundación Mundo Sano
- ,Argentina
- Hospital de Niños Ricardo Gutiérrez, Buenos Aires
- ,Argentina
- Hospital Donación Francisco Santojanni
- ,Argentina
- Hospital Francisco Javier Muñiz
- ,Argentina
- INP Dr. Mario Fatala Cháben
- ,Argentina
- Instituto de Cardiología de Corrientes
- ,Argentina
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET)
- ,Argentina
- ISGlobal, Barcelona Institute for Global Health
- ,Spain
- Laboratorio Elea Phoenix S.A.
- ,Argentina
- Luxembourg Institute of Health
- ,Luxembourg
- Ministry of Health (Bolivia)
- ,Bolivia
- Ministry of Health Argentina
- ,Argentina
- Núcleo de Desenvolvimento Farmacêutico e Cosmético (NUDFAC)
- ,Brazil
- Oswaldo Cruz Foundation – Fiocruz
- ,Brazil
- Platforms of Integral Care for Patients with Chagas Disease
- ,Bolivia
- Universidad Autónoma Juan Misael Saracho
- ,Bolivia
- Universidad Mayor de San Simon
- ,Bolivia
- Vall d’Hebron University Hospital
- ,Spain
- Centro de Enfermedad de Chagas y Patologia Regional Hospital Independencia, Argentina
- Collective of Applied Studies and Social Development (CEADES), Bolivia
- Eisai Co., Ltd., Japan
- FP Clinical Pharma – Ethel Feleder, Argentina
- Fundacio Investigacio Hospital General Valencia, Spain
- Fundación Mundo Sano, Argentina
- Laboratorio Elea Phoenix S.A., Argentina
- Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina
- ISGlobal, Barcelona Institute for Global Health, Spain
- INP Dr. Mario Fatala Cháben, Argentina
- Luxembourg Institute of Health, Luxembourg
- Núcleo de Desenvolvimento Farmacêutico e Cosmético (NUDFAC), Brazil
- Platforms of Integral Care for Patients with Chagas Disease, Bolivia
- Universidad Autónoma Juan Misael Saracho, Bolivia
- Universidad Mayor de San Simon, Bolivia
- Vall d’Hebron University Hospital, Spain
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Argentina
- Fundación Huésped, Argentina
- Hospital Donación Francisco Santojanni, Argentina
- Hospital Francisco Javier Muñiz, Argentina
- Instituto de Cardiología de Corrientes, Argentina
- Oswaldo Cruz Foundation – Fiocruz, Brazil
- Ministry of Health Argentina, Argentina
- Ministry of Health (Bolivia), Bolivia
- Germany - Federal Ministry of Education and Research (BMBF) through KfW
- Germany - Federal Ministry for Economic Cooperation and Development (BMZ) through KfW
- Japan - Global Health Innovative Technology Fund (GHIT Fund)
- Switzerland - Swiss Agency for Development and Cooperation (SDC)
- The Netherlands - Dutch Ministry of Foreign Affairs (DGIS)
- UK - UK International Development
- Mundo Sano (PRV)
- Médecins Sans Frontières International
- Other private foundations and individuals
- Starr International Foundation
- The Rockefeller Foundation (through the “Next Century Innovators Award”)
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