Ziresovir Eases Bronchiolitis Symptoms in RSV Babies

For infants and young children hospitalized with respiratory syncytial virus (RSV) infection, ziresovir has been found to alleviate signs and symptoms of bronchiolitis, according to a study published in the September 26 edition of the New England Journal of Medicine.

The research, conducted by Shunying Zhao, M.D., Ph.D., and colleagues from Beijing Children's Hospital, involved a phase 3, multicenter trial. Participants, aged 1 to 24 months and hospitalized due to RSV infection, were randomly assigned to receive either ziresovir or a placebo. The dosing of ziresovir was determined based on the body weight of the participants, ranging from 10 to 40 mg, administered twice daily for five days in a 2:1 ratio of ziresovir to placebo. The study's intention-to-treat population consisted of 244 participants, while the safety population included 302 participants.

The results demonstrated a significantly greater reduction in the Wang bronchiolitis clinical score by day three for those treated with ziresovir compared to those given the placebo (−3.4 versus −2.7 points). By the fifth day, the reduction in the RSV viral load was more substantial in the ziresovir group than in the placebo group (−2.5 versus −1.9 log 10 copies/mL). This trend was consistent in prespecified subgroups, including participants with a baseline bronchiolitis score of 8 or higher and those aged six months or younger.

The study also reported the incidence rates of adverse events related to the drug or placebo, which were 16 percent and 13 percent, respectively. These findings suggest that ziresovir treatment in infants and young children hospitalized with RSV infection leads to a significantly greater resolution of RSV-associated signs and symptoms and a more substantial decrease in viral load compared to a placebo.

The research received funding from Shanghai Ark Biopharmaceutical, the company developing ziresovir.