FDA Committee Strongly Supports RSV Vaccine to Protect Infants

An FDA panel strongly endorsed Thursday that it could be the first maternal respiratory syncytial virus (RSV) vaccine approved to protect infants from the annual epidemic.

All 14 members of the Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted unanimously to conclude that the available data suggest that Pfizer’s RSV prefusion F administered to mothers in the second or third trimester of pregnancy He said that the protein vaccine is effective in preventing RSV. Illnesses associated with lower respiratory tract disease in infants, including severe cases.

VRBPAC also favored the safety profile of the vaccine 10 to 4, citing that most of the concerns centered on imbalances in preterm births.

Overall, however, the focus has been on the potential of this first-of-its-kind vaccine to prevent severe RSV disease in infants.

“If the vaccine actually lives up to the data we see today, we can guarantee that many babies and their parents will breathe easier in the years to come,” said Jay Portnoy, M.D., of Children’s Mercy Hospital in Kansas City, Missouri. I can,” he said. He voted in favor of vaccine efficacy and safety.

As for safety, he said, “I’m not worried about adverse effects on mothers.” “I’m worried that my child will be born a little earlier.”

“The problem is that if the child is born early, the treatment will be less effective, because fewer antibodies will be transferred,” Portnoy continued. “So this is a very complicated thing because the harm actually reduces the benefit. So there is an interaction between the two.”

During the discussion leading up to the vote, CDC’s Amanda Cohn, M.D., said the Phase 3 trial data supporting the vaccine was “incredible.”

“Having done this vaccine trial in pregnant women is a big achievement in itself,” said Cohn, who voted “yes” to both questions. “I feel we need to set the bar higher.”

He noted that several vaccine trials, including those for COVID-19, are involving more participants to assess safety.

“That’s not to say we don’t think this vaccine is incredibly valuable,” Cohn said, adding, “We’re going to get more people into clinical trials and see very strong post-licensing evaluations. Getting a … will be necessary to reassure the public,” he said. It is intended to provide pregnant women with the data they need to make vaccination decisions. “

The data supporting Pfizer’s vaccine, given the proposed trade name Abrysvo, is largely Global Phase III Study (MATISSE) Nearly 7,000 infants were enrolled, and mothers were vaccinated with 120 μg in the third trimester. (The maternal vaccine is identical to the company’s geriatric vaccine candidate, VRBPAC support It took place earlier this year and is currently under review with the FDA. )

This product demonstrated a vaccine efficacy (VE) of 81.8% (99.5% CI 40.6-96.3) and a VE of 69.4% (97.58% CI 44.3) for severe RSV-associated lower respiratory tract disease in infants <90 days of age. showed. -84.1) At 180 days of age, cases occurred in 0.5% of the vaccine group and 1.8% of the placebo group.

According to safety data released Thursday, no significant difference was observed between the vaccine and placebo groups among pregnant women in terms of the overall incidence of unanticipated adverse events (AEs) within one month after vaccination. it wasn’t. Common adverse events for vaccinees included fatigue (46% vs. 44% in the placebo group), headache (31% vs. 28%), myalgia (27% vs. 17%), and injection site pain (41%). 10%) were included. However, most were mild to moderate and resolved within a few days.

One maternal death in the vaccine group was due to postpartum hemorrhage and hypovolemic shock, which both the investigators and the FDA considered unrelated to the product.

AEs and serious AEs in infants were reported with similar frequency across the two study arms. However, a statistically non-significant imbalance was observed for preterm birth. In the vaccine group, 5.7% of her infants were born prematurely, compared with 4.7% of him in the placebo group.

At the time of data cutoff, the sponsor identified 5 infant deaths in the vaccine group compared with 12 in the placebo group. One death from prematurity-related complications associated with an infant born very prematurely in the vaccine group 10 days after maternal vaccination could not be ruled out as vaccine-related by the FDA.

Pfizer said during the conference that pharmacovigilance studies will continue to monitor results in both maternal and child populations.

FDA is not obligated to follow advisory committee recommendations, but it usually does.