A phase 1 clinical trial suggests that the m102.4 antibody is well tolerated and safe for use as a treatment against henipaviruses.
The emerging henipavirus group has generated concern about its potential to cause a pandemic. Nipah virus, which was identified about 2 decades ago in Malaysia, caused serious outbreaks in India in 2018 and 2019.
There are currently no approved vaccines or treatments in place to address the potentially fatal infections caused by henipaviruses. But an antibody treatment designed to neutralize the virus has been deemed safe and well-tolerated, according to a study team which published results from a phase 1 clinical trial in The Lancet Infectious Diseases.
The monoclonal antibody assessed, m102.4, has successfully neutralized henipaviruses in previous experiments with non-human primates. While this trial took place in healthy human participants, the promising findings likely clear the way for further trials of efficacy in infected human patients.
The clinical trial enrolled 40 healthy adults between 18 and 50 years of age. Between March 27, 2015 and June 16, 2016, participants were randomly assigned to 1 of 5 groups. A total of 8 individuals were placed in each cohort, wherein 6 received the treatment and 2 received a placebo.
In the first 4 groups, trial participants received the antibody treatment in single doses ranging from 1 mg/kg to 20 mg/kg. The fifth group received 2 doses of 20 mg/kg, 72 hours apart.
The most common treatment related adverse event was headache, which occurred in 12 of 30 participants in the various m102.4 treatment groups and 10 of the participants who received a placebo.
A total of 86 treatment emergent adverse events were reported, at similar rates between the treatment and placebo groups. Of these, 29 events in 20 participants were considered treatment related. There were no deaths, no severe adverse events, and no adverse events leading to discontinuation of the study.
The investigators tested blood samples from participants, finding that the circulating antibody did not generate an immune response against itself and displayed activity against Hendra and Nipah viruses in all samples. The antibody was found to remain active for at least 8 days following intravenous administration.
While further evaluation of m102.4 efficacy in real-world clinical situations will be necessary, m102.4 could be a helpful tool for post-exposure prophylaxis against henipaviruses.
“Based on the results of our trial, we suggest offering a single dose of 20mg/kg of m102.4 to people likely to have been exposed to one of the viruses, or two doses separated by 48 hours to patients with clinical signs of infection," study author Heidi Carroll, MBBS, MPH, medical director of the Communicable Diseases Branch at Queensland Health, said in a press release.