GlaxoSmithKline’s RSV vaccine Arexvy is now available for at-risk adults age 50-59 in addition to those age 60 and older.

  1. The FDA approved GSK’s RSV vaccine, Arexvy, for adults aged 50-59 with increased risk, expanding its use beyond those aged 60 and older.
  2. The approval is based on positive Phase III trial results showing effective immune response and safety in adults aged 50-59, including those with chronic conditions.
  3. GSK is seeking to extend the vaccine’s use to this age group in Europe, Japan, and other regions, with ongoing trials for adults aged 18-49 and immunocompromised individuals.

The US FDA has expanded the approval of Arexvy to the prevention of RSV lower respiratory tract disease (LRTD) in adults 50 through 59 years of age who are at increased risk, according to GlaxoSmithKline (GSK).

The vaccine was previously approved for use in adults aged 60 and older and recommended by CDC/ACIP using shared clinical decision-making.  

A systematic review of studies in the US showed that RSV is estimated to cause 42,000 hospitalizations each year in adults aged 50-64 years old. Adults with underlying medical conditions, such as chronic obstructive pulmonary disease (COPD), asthma, heart failure and diabetes are at increased risk for severe consequences from an RSV infection compared to those without these conditions. RSV can exacerbate these conditions and lead to pneumonia, hospitalization or death.

“Today’s approval reflects the importance of broadening the benefits of RSV immunization to adults aged 50-59 who are at increased risk. For those with underlying medical conditions, RSV can have serious consequences, so we are proud to be the first to help protect them from RSV-LRTD,” said Tony Wood, Chief Scientific Officer. 

The regulatory application was supported by positive results from a phase III trial [NCT05590403] evaluating the immune response and safety of GSK’s RSV vaccine in adults aged 50-59, including those at increased risk for RSV-LRTD due to certain underlying medical conditions. 

“I am thrilled that GSK’s RSV vaccine is now approved for adults aged 50-59 at increased risk of RSV-LRTD. When it comes to the risks associated with RSV, age is just a number, an important number, but not the only factor to consider. Many adults in this age group have underlying health conditions that place them at increased risk for serious illness with RSV infection compared with those without these conditions. Now there is a vaccine approved that can help protect them,” said professor Ann R. Falsey, University of Rochester School of Medicine. 

GSK has also filed regulatory submissions to extend the use of its RSV vaccine to adults aged 50-59 at increased risk in Europe, Japan and other geographies with regulatory decisions undergoing review. Trials evaluating the immunogenicity and safety of the vaccine in adults aged 18-49 at increased risk and immunocompromised adults aged 18 and over are expected to read out in H2 2024.   

Arexvy RSV vaccine 

Respiratory Syncytial Virus Vaccine, Adjuvanted, contains recombinant RSV glycoprotein F stabilized in the prefusion conformation (RSVPreF3). This antigen is combined with GSK’s proprietary AS01adjuvant.  

In May 2023, the FDA approved GSK’s RSV vaccine for the prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus (RSV) in individuals 60 years of age and older. The use of this vaccine should be in accordance with official recommendations. As with any vaccine, a protective immune response may not be elicited in all vaccines. 

The vaccine has also been approved for the prevention of RSV-LRTD in individuals 60 years of age and older in over 40 countries, including Europe, Japan and US. Regulatory reviews in multiple countries are ongoing. The proposed trade name remains subject to regulatory approval in other markets. 

The GSK proprietary AS01 adjuvant system contains STIMULON QS-21 adjuvant licensed from Antigenics Inc, a wholly owned subsidiary of Agenus Inc. STIMULON is a trademark of SaponiQx Inc., a subsidiary of Agenus. 

NCT05590403 trial  

NCT05590403 is a phase III, placebo-controlled, observer-blind, randomized, multi-country immunogenicity trial to evaluate the non-inferiority of the immune response and evaluate safety in participants aged 50 to 59, including those at increased risk for RSV-LRTD compared to older adults aged 60 years and above after a single dose of GSK’s RSV vaccine.  

The study assessed the immune response in participants aged 50 to 59 with pre-defined stable chronic diseases leading to an increased risk for RSV disease (n=570). Immune responses in a broader group of participants aged 50-59 years without these pre-defined chronic diseases (n=570) were also evaluated compared to adults aged 60 and older. The trial’s primary endpoints were RSV-A and RSV-B neutralization titres of both groups at one month after the vaccine administration compared to adults aged 60 and older. There were also safety and immunogenicity secondary and tertiary endpoints. Safety and reactogenicity data were consistent with results from the initial AReSVi-006 data read out. The most common local adverse event was pain. The most common systematic adverse events were myalgia, fatigue and headache, which were largely transient and mild to moderate in intensity. 

Results from this trial have been presented at the ACIP meeting of October 2023 and at ReSVinet in February 2024, and have been submitted for peer-reviewed publication. The data are being submitted to other regulators to support potential label expansions.