Dengue monoclonal antibody Phase III randomised double-blind clinical trial for the treatment of symptomatic dengue in children and adult participants
| ISRCTN | ISRCTN50970152 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN50970152 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | DNDi-DmAb-01-DEN |
| Sponsor | Drugs for Neglected Diseases Initiative |
| Funders | Drugs for Neglected Diseases initiative, German Federal Ministry of Research, Technology and Space (BMFTR) |
- Submission date
- 07/11/2025
- Registration date
- 12/11/2025
- Last edited
- 11/11/2025
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
Plain English summary of protocol
Background and study aims
Dengue is a viral illness spread by mosquitoes and affects millions of people each year, especially in tropical and subtropical regions. While many people recover without complications, some develop severe symptoms that can lead to hospitalization or even death. Currently, there is no specific treatment for dengue—only supportive care to manage symptoms.
This study aims to test a new potential treatment: a monoclonal antibody called SII Dengue mAb. Monoclonal antibodies are lab-made proteins that help the body fight infections. SII Dengue mAb is designed to neutralize all four types of dengue virus and may help people recover faster and avoid severe illness.
The purpose of this study is to find out whether a single dose of Dengue-mAb given through an intravenous (IV) infusion can safely and effectively reduce the time it takes for people with dengue to recover, and whether it can prevent the disease from getting worse.
Who can participate?
People can take part in this study if they meet the following conditions:
1. They are at least 5 years old.
2. They have symptoms of dengue and a positive test result for dengue (either NS1 antigen or PCR test).
3. Their symptoms started within the last 72 hours.
People will not be able to participate if they already have severe dengue, certain warning signs, serious medical conditions, allergies to the study drug, or have recently received certain vaccines or treatments.
What does the study involve?
This is a Phase III clinical trial, which means the treatment has already been tested in earlier studies and is now being evaluated in a larger group of people.
Participants will be randomly assigned to one of two groups:
• Group 1 will receive Dengue-mAb (the study drug).
• Group 2 will receive a placebo (a harmless solution that looks like the study drug but has no active ingredients).
Both treatments are given as a single IV infusion on the first day of the study. The infusion lasts about 1 hour, and participants will be monitored closely afterward.
After treatment, participants will have daily follow-up visits for 6 days, and possibly longer if symptoms continue. There will also be a visit on Day 28 and a phone call at Month 4 to check on their health and recovery.
During the study, doctors will monitor participants’ symptoms, vital signs, blood tests, and other health indicators. The study will look at how quickly participants recover, whether they develop severe symptoms, and whether the treatment is safe.
What are the possible benefits and risks of participating?
Benefits
• Participants may recover faster from dengue.
• The treatment may reduce the risk of developing severe dengue.
• Participants will receive close medical monitoring and care during the study.
Risks
• As with any medication, there may be side effects, such as reactions to the infusion (e.g. fever, rash, or fatigue).
• Blood tests and other procedures may cause minor discomfort.
• There is a chance the treatment may not work or may cause unexpected effects.
All participants will receive standard supportive care for dengue, regardless of which group they are in.
Where is the study run from?
This study is sponsored by the Drugs for Neglected Diseases initiative (DNDi), based in Geneva, Switzerland. The trial will be conducted at multiple hospitals and research centers in Brazil, Malaysia, and Thailand.
When is the study starting and how long is it expected to run for?
The study is expected to start in Q3 2026 and will run for approximately 4 months for each participant. The overall trial is expected to last approximatively 3 years, depending on how quickly participants will be enrolled.
Who is funding the study?
The study is funded and sponsored by the Drugs for Neglected Diseases initiative (DNDi), a non-profit organization that develops treatments for diseases affecting vulnerable populations.
Who is the main contact?
The medical lead for the study is:
Dr. André Siqueira, MD, PhD
Head of Dengue Global Programme
Email: asiqueira@dndi.org
Contact information
Scientific, Principal investigator
Drugs for Neglected Diseases initiative (DNDi)
Rua São José, 70 | Sala 601
Rio de Janeiro
20010-020
Brazil
| Phone | + 55 21 2529-0417 |
|---|---|
| asiqueira@dndi.org |
Public
Drugs for Neglected Diseases initiative (DNDi)
15 Chemin Camille-Vidart
Geneva
1202
Switzerland
| Phone | + 41 22 907 77 22 |
|---|---|
| apretre@dndi.org |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Multicentre parallel-group double-blind randomized placebo-controlled phase III interventional clinical trial with allocation by IVRS and masking of participants and clinical assessors |
| Secondary study design | Randomised parallel trial |
| Scientific title | A parallel-group, double-blind, randomised, two arms, placebo-controlled, multicentre Phase III clinical trial to evaluate the efficacy (time reduction to sustained recovery) and safety of a single-dose intravenous infusion of dengue monoclonal antibody in male and female children aged ≥5 years and adults aged ≥18 years with symptomatic dengue |
| Study objectives | Demonstrate that Dengue monoclonal antibody compared to placebo reduces the time to sustained recovery from dengue fever |
| Ethics approval(s) |
1. Not yet submitted 2. Not yet submitted 3. Not yet submitted |
| Health condition(s) or problem(s) studied | Dengue |
| Intervention | Participants will be randomized in a 1:1 ratio using an Interactive Voice Response System (IVRS) into one of two study arms: SII Dengue mAb or matching placebo. In Arm 1, participants will receive a single intravenous infusion of Dengue-mAb (VIS513) at a dose of 6 mg/kg over 1 hour, with the possibility of extending up to 3 hours in case of infusion-related adverse events. In Arm 2, participants will receive a matching placebo (formulation buffer without active ingredient) at 0.24 mL/kg body weight, administered under the same conditions. All participants will be followed for a total duration of up to 4 months, including: * Daily visits from Day 2 to Day 7 (intensive follow-up), * Optional daily visits from Day 8 to Day 27 if dengue symptoms persist, * A visit on Day 28, * A phone follow-up at Month 4 for final safety assessment and evaluation of late symptoms. |
| Intervention type | Drug |
| Phase | Phase III |
| Drug / device / biological / vaccine name(s) | SII Dengue mAb |
| Primary outcome measure(s) |
Time to sustained recovery is measured using clinical and laboratory assessments including temperature monitoring, haematocrit stability, platelet count, and absence of dengue warning signs and severe dengue criteria, assessed daily from Day 1 to Day 28. |
| Key secondary outcome measure(s) |
1. Treatment-emergent adverse events (TEAEs) are measured using clinical assessments and laboratory tests from Day 1 to Month 4 |
| Completion date | 30/06/2029 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 5 Years |
| Upper age limit | 99 Years |
| Sex | All |
| Target sample size at registration | 1266 |
| Key inclusion criteria | 1. At least 5 years of age inclusive, at the time of signing the informed consent 2. Diagnosed for Dengue by NS1 antigen or PCR positive 3. Start of investigational medicinal product (IMP) infusion within 72 hours of onset of any clinical symptom of dengue |
| Key exclusion criteria | 1. Presence of dengue warning signs 2. Presence of severe dengue criteria 3. Clinically unstable medical conditions that may interfere with drug metabolism, pose a risk during participation, or affect data interpretation 4. Known allergies or hypersensitivity to humanized monoclonal antibodies or any component of the investigational product 5. History or evidence of significant active bleeding or coagulation disorders 6. Recent or planned receipt of live-attenuated vaccines within 28 days prior to dosing or during the follow-up period 7. Recent treatment with biologic agents, including monoclonal antibodies, within 12 weeks or 5 half-lives (whichever is longer) prior to dosing |
| Date of first enrolment | 31/08/2026 |
| Date of final enrolment | 28/02/2029 |
Locations
Countries of recruitment
- Brazil
- Malaysia
- Thailand
Study participating centres
Rio de Janeiro
21040-360
Brazil
Bangkok
10700
Thailand
Klang
41000
Malaysia
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not expected to be made available |
| IPD sharing plan |
Editorial Notes
11/11/2025: Trial's existence confirmed by Federal Ministry of Research, Technology and Space.
