Abrysvo is currently endorsed across various continents — in America, Europe, and Japan to cite a few — safeguarding expectant mothers, adults aged 60 and above, and subsequently their unborn babies. However, an approved vaccine specialized to guard younger high-risk adults against RSV globally does not exist until now.
RSV holds a significant imprint on American healthcare records, leading to a considerable number of hospitalizations and deaths amidst infants and older Americans annually. High-risk adults with underlying health conditions like asthma and diabetes or compromised immune systems are susceptible to severe illness induced by RSV. As reported by Pfizer, chronic conditions that amplify the risk of acute RSV disease impact around 10% of American adults aged 18 to 49 and approximately 24% of individuals between 50 to 64 years old.
Dr. Iona Munjal, Pfizer’s Clinical Vaccine Research and Development Executive Director, stated that their next target is high-risk adults aged 18 to 59 in their endeavor to reduce RSV disease rates across older populations.
This promising data came at the right time as Pfizer, after trailing behind GlaxoSmithKline (GSK) last year, is now focused on gaining more traction in the RSV market. GSK’s RSV solution catering to adults aged 60 and above garnered around $1.5 billion in sales last year, while Pfizer’s shot gained momentum with approximately $890 million in revenue in 2023.
Pfizer is preparing to present the clinical data to regulatory bodies and pursue expanded approval for Abrysvo for individuals aged 18 and older. However, the proposed timeline and details remain unrevealed by the company.
The stage III trial’s primary objectives addressing efficacy and safety in high-risk adults aged 50 to 59 were met, Pfizer confirmed. They focused on roughly 700 patients with underlying health issues prone to severe RSV. The company is due to share data on another group of around 200 patients with weakened immune systems later this year.
A single dose of Abrysvo elicited immune responses against RSV A and RSV B — the critical residing virus subtypes. According to Pfizer, the induced reaction is on par with that observed in adults aged 60 and older. The vaccine elicited a four-fold augmentation in protective antibodies against RSV A and RSV B, one month post-vaccination, compared to pre-vaccination levels.
Pfizer conveyed that safety data for high-risk adults aged 18 to 59 correlated with results seen in adults aged 60 and above. The vaccine was well-received and tolerated in the trial.
In another development, GSK reported late-stage trial data last October, indicating that its shot could safeguard adults aged 50 to 59. The FDA (Food and Drug Administration) bolstered GSK’s application to broaden the drug’s approval, Arexvy, to this new demographic by granting a “priority review” last February. If approved, it could speed up the review procedure for specific drugs treating severe conditions. The decision on whether to ratify GSK’s RSV vaccine for adults aged 50 to 59 is due on June 7.
