GSK Secures First FDA Approval for an RSV Vaccine for Older Adults

Despite valiant efforts by other pharmaceutical companies — namely, Pfizer — GSK has secured its spot in the respiratory syncytial virus (RSV) vaccine market, becoming the first-ever FDA-approved RSV vaccine for older adults. The approval, announced by GSK and the FDA on May 3, 2023, was a long-time coming as pharmaceutical manufacturers have raced to fill this healthcare gap.

According to GSK, Arexvy is a dual-component vaccine with recombinant subunit prefusion RSV F glycoprotein antigen (RSVPreF3) and an AS01E adjuvant.

Like the flu and other seasonal illnesses, RSV is a cyclical respiratory virus commonly contracted in the fall and winter. In most individuals, the infection causes mild, flu-like symptoms, including congestion, runny nose, dry cough, fever, sore throat, headache, and more. However, some patient populations, including infants, young children, immunocompromised people, and elderly adults, are significantly more at risk for severe infection.

In higher-risk patient populations, including adults over 60, RSV has been linked to life-threatening conditions such as pneumonia and bronchiolitis. The FDA notes that RSV is linked to 60,000–120,000 hospitalizations in adults over 65 annually. Additionally, an estimated 6,000–10,000 deaths yearly among people over 65 are connected to RSV.

With the considerable risks and lack of available treatment options, the healthcare industry has been eyeing preventative measures for this infection.

“Older adults, in particular those with underlying health conditions, such as heart or lung disease or weakened immune systems, are at high risk for severe disease caused by RSV,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, in the FDA press release.

The approval was based on data from an ongoing clinical trial that recruited 25,000 adults over 60. Half of the participants received Arexvy, while the other half received a placebo. Based on data from one RSV season, the drug reduced the risk of RSV lower respiratory tract disease by 82.6%. In addition, the risk of severe disease was 94.1% lower in the experimental group.

Despite the benefits of this drug, there are some notable side effects, including injection site pain, muscle pain, headache, joint pain, and fatigue. Some patients also had atrial fibrillation; however, the percentage of patients was relatively low, with only ten reported cases for experimental group participants.

In addition, previous studies on the drug identified some concerning adverse effects. Two patients who received Arexvy and a flu vaccine simultaneously developed acute disseminated encephalomyelitis. Additionally, one patient developed Guillain–Barré syndrome.

Despite these complications, Marks added, “Today’s approval of the first RSV vaccine is an important public health achievement to prevent a disease which can be life-threatening and reflects the FDA’s continued commitment to facilitating the development of safe and effective vaccines for use in the United States.”

Although the drug has been approved and is expected to roll out by the next RSV season, the FDA has asked GSK to conduct post-marketing studies. Additionally, GSK will continue following the trial participants for two more RSV seasons.