RIO DE JANEIRO — A Phase III clinical trial of an experimental monoclonal antibody treatment for dengue is scheduled to begin in Brazil, Malaysia and Thailand, according to a clinical-trial registry, in a study that could help advance one of the leading candidates for a specific treatment for the mosquito-borne disease.
The trial, sponsored by the Drugs for Neglected Diseases initiative (DNDi), is listed as due to begin on Aug. 31 and is not yet recruiting. It is designed to enroll 1,266 people aged five and older with symptomatic dengue and will compare a single intravenous dose of the investigational antibody with a placebo.
The treatment, known as SII Dengue mAb and formerly called VIS513, was developed by Serum Institute of India (SII). The trial will be conducted at research sites including Fiocruz in Rio de Janeiro, Siriraj Hospital in Bangkok and a health clinic in Klang, Malaysia, according to the registry.
The primary objective is to determine whether the antibody reduces the time needed for patients to achieve sustained recovery. Researchers will also assess safety, viral-load reduction, progression to warning signs or severe dengue, hospitalization and death related to disease progression. Participants will receive either the antibody or matching placebo alongside standard supportive care.
The registry says the first participant is expected to be enrolled on Aug. 31, with final enrollment planned for February 2029 and overall study completion targeted for June 2029. It lists the trial as not yet recruiting.
The schedule differs from a July announcement by DNDi and SII, which said the multinational Phase III study was expected to begin in the first quarter of 2027. DNDi said at the time that about 1,000 participants were expected across the three countries. The newer registry record lists a target of 1,266 participants and a third-quarter 2026 start.
SII has already conducted preclinical studies and Phase I and II trials of the antibody and is leading a separate pivotal Phase III trial in India, DNDi said. SII will supply the investigational medicine and oversee refrigerated transportation for the multinational study.
Dengue has no specific antiviral treatment, according to the World Health Organization, which in May issued target product profiles to guide development of treatments for both non-severe and severe disease. Current management relies primarily on supportive care and monitoring for complications.
The three-country trial remains listed as not yet recruiting, with enrollment scheduled to begin later in August, according to the clinical-trial registry.
