Pfizer’s RSV Vaccine Shows Potential for High-Risk Adults
Pfizer announced promising results from a late-stage clinical trial of its respiratory syncytial virus (RSV) vaccine, Abrysvo. The data suggests that the vaccine could provide protection to high-risk adults aged 18 to 59 who are at an increased risk of severe illness from RSV. Currently, there are no approved RSV vaccines for this age group worldwide.
RSV is a virus that causes hospitalizations and deaths among older Americans and infants each year. It can also lead to severe illness in younger adults with weakened immune systems or underlying chronic conditions such as asthma and diabetes. According to Pfizer, nearly 10% of US adults aged 18 to 49 have a chronic condition that puts them at risk of severe RSV disease.
Dr. Iona Munjal, Pfizer’s executive director of clinical vaccine research and development, emphasized the importance of vaccination for high-risk adults. She stated that this population is at risk of getting RSV every winter without durable immunity through vaccination.
The potential expansion of Abrysvo’s approval to include adults aged 18 and up could greatly benefit a significant portion of the population. Pfizer plans to submit the data to regulatory agencies and file for expanded approval. The timeline for these plans has not been disclosed.
This development comes as Pfizer aims to gain a larger share of the RSV market, which was dominated by GlaxoSmithKline (GSK) last year. GSK’s RSV vaccine for adults aged 60 and above generated approximately £1.2 billion ($1.5 billion) in sales in 2023, while Pfizer’s shot recorded about $890 million in revenue.
Pfizer’s vaccine met the main efficacy and safety goals in high-risk adults aged 50 to 59 during the phase three trial. The company released data on a sub-study involving nearly 700 patients with underlying medical conditions and plans to release data on another sub-study involving approximately 200 patients with weakened immune systems later this year.
The results showed that a single dose of Abrysvo elicited an immune response against the two major subtypes of RSV, similar to the response observed in adults aged 60 and above. The levels of protective antibodies against RSV A and RSV B increased fourfold one month after vaccination. The vaccine was well-tolerated in the trial, with safety data consistent with results in older adults.
GSK also released late-stage trial data suggesting that its RSV vaccine could protect adults aged 50 to 59. The US Food and Drug Administration (FDA) granted “priority review” to GSK’s application to expand approval of its drug, Arexvy, to this new age group. The FDA is expected to make a decision on June 7.
Overall, Pfizer’s RSV vaccine shows promise in expanding protection to high-risk adults aged 18 to 59. The potential approval of Abrysvo for this age group could have significant implications for reducing the burden of RSV disease and improving the health outcomes of vulnerable individuals. Further research and regulatory processes will determine the future availability of this vaccine.
