Global Courant
An independent Food and Drug Administration advisory committee voted Thursday to recommend an injectable drug that could protect babies up to 2 years old from RSV.
The 21-member panel voted unanimously to recommend the injection for newborns and infants during their first months of exposure to RSV. The group also voted 19 to 2 to give a second dose to children up to age 2 who are vulnerable to severe infections — such as children with chronic heart or lung disease — during their second season of RSV.
The FDA must now decide whether to approve the injection, but will likely follow the committee’s recommendation.
Respiratory syncytial virus causes lower respiratory tract disease and is most serious for older adults and adults babies under 6 months. In children under 5 years what the virus leads to up to 80,000 hospitalizations and up to 300 deaths per year in the US. Most people become infected at the age of 2 years.
The monoclonal antibody drug under consideration is administered as a single injection and functions similarly to a vaccine. But instead of prompting the immune system to develop antibodies against the virus, it delivers those antibodies directly to the bloodstream. Scientists call this passive immunization. Monoclonal antibodies were also used to treat Covid before new variants rendered them ineffective.
“It’s a temporary shield, whereas when there’s active immunization, you have memory immunity that can come to the rescue months or years later,” said Dr. Ofer Levy, the director of the Precision Vaccines Program at Boston Children’s Hospital, who was not. involved in Thursday’s vote.
Active immunization refers to the protection against vaccines, but no RSV vaccine for infants has been approved.
The new monoclonal antibody, called nirsevimab, is sold under the name Beyfortus and is already approved in Europe, Canada and the United Kingdom. It was developed by pharmaceutical giant AstraZeneca in collaboration with Sanofi.
In a study of nearly 1,500 infants, the injection reduced the risk of developing respiratory disease from RSV that required a doctor’s visit by nearly 75% for at least five months.
In a study of more than 1,400 premature babies – a group at particular risk – the injection was found to reduce the risk of developing a respiratory disease from RSV, which required doctor visits, by about 70% for at least five months. It lowered the risk of hospitalization from RSV by about 78% over that time.
“The studies presented showed clear evidence of efficacy and reassuring evidence of safety in all subgroups presented, and I think this could be a real game changer,” said Dr. George Siberry, a member of the FDA panel and a medical officer with the US Agency for International Development.
Sally Hunsberger, a biostatistician at the National Institutes of Health, was one of two committee members who voted not to recommend the injection for high-risk children up to age 2.
“It’s a bit of a weak ‘no,’ but hopefully that will just emphasize that I feel like we need more data,” Hunsberger said.
Rates of RSV infections typically increase in the fall and peak in the winter. However, last year’s season began in June and peaked in November, and resulted in a dramatic spike in serious illnesses overwhelming children’s hospitals.
AstraZeneca said Thursday that if the drug is approved, babies born from April to October before the upcoming RSV season could be immunized at their pediatrician’s office. Babies born between November and March can be immunized after birth before they leave the hospital.
The company estimated that the injection could prevent up to 500,000 medical visits per year, including up to 60,000 hospitalizations.
In a briefing paper, the FDA determined that the injection was safe based on the results of three studies involving a total of more than 3,600 participants. Of the healthy and preterm infants vaccinated during their first RSV season, a small minority developed a rash as a side effect. Some infants at high risk for severe RSV developed a fever.
The FDA noted that there was a higher number of deaths among infants who received the injection compared to those who received a placebo or other antibody injection, but the agency determined that the discrepancy was likely unrelated to AstraZeneca’s drug.
The company said on Thursday it should be safe to give the shot alongside routine childhood vaccines, such as flu shots.
The FDA has already approved one monoclonal antibody injection to protect babies against RSV: a drug called Synagis. But it’s only approved for high-risk babies and must be given monthly during RSV season. The drug reduced the risk of RSV hospitalization by 45% to 55% in studies.
A vaccine given to mothers during pregnancy to protect babies against RSV may also be approved soon: FDA advisers voted last month to recommend that shot. The vaccine, made by Pfizer, reduced the risk of serious illness from RSV in infants by 82% within about three months of birth. After about six months, the efficacy was about 69%.
The FDA said Thursday it wasn’t sure whether babies who already had protection from Pfizer’s injection would see an added benefit or new safety concerns if they also received the AstraZeneca injection.
The FDA approved the world’s first RSV vaccine for adults age 60 and older in early May. Last week, the agency approved a second vaccine for older adults, made by Pfizer and using the same formulation that could be given to pregnant people.
