Monoclonal for Dengue Shows Promise in Hospitalized Cases

An experimental monoclonal antibody called Dengue-mAb showed promise in a recent trial in India, according to a placebo-controlled phase II study. The research, led by Prasad Kulkarni of Serum Institute of India, involved 249 hospitalized adults with dengue and a history of fever. The participants were randomized to receive one of four doses of Dengue-mAb or a placebo.

The results demonstrated that the monoclonal antibody significantly reduced viral loads and infection symptoms. Compared to placebo, 3 mg/kg, 5 mg/kg, 7 mg/kg, and 9 mg/kg doses of Dengue-mAb resulted in a lower viral load at 24 hours after treatment (P < 0.001). Additionally, the antibody improved virus clearance in the blood, with 71.4% of placebo patients becoming viremia-free eight hours post-treatment, compared to 71.4% to 100% of those who received the higher-dose treatments.

Notably, no participants in any of the study groups experienced treatment-related serious adverse events. The researchers highlighted this as the first evidence of a potential therapeutic effect in dengue patients. While the sample size was small, the observed reductions in viremia, RNAemia, and fever clearance could lead to a decrease in illness severity and dengue transmission.

Dengue virus, transmitted through mosquito bites, is a rapidly spreading mosquito-borne disease. In 2024, there were a record 14.1 million cases globally, resulting in 9,508 deaths with a 0.07% case fatality rate. The disease is more prevalent in tropical and subtropical regions, but U.S. cases surged to 3,798 in 2024, up from an average of 828 cases annually from 2010-2023.

Typically, dengue infections are asymptomatic or mild, presenting with symptoms like headache, fever, body aches, nausea, and rash. However, severe cases can result in neurologic complications, such as Guillain-Barré syndrome, and even death. Currently, no approved antiviral treatments exist for dengue, with standard approaches focusing on pain management and hydration.

The trial included adults aged 18 to 60 years who presented to a hospital within 48 hours of fever onset and had dengue confirmed through a rapid antigen test. The primary outcomes measured were viral log reductions and the percentage of patients with fever clearance at 24 hours after treatment. Overall, 23.3% of patients experienced adverse events, all of which were in the Dengue-mAb groups but resolved without sequelae.