mRNA-1345 RSV vaccine could be more than 80% effective

mRNA vaccine company Moderna (Nasdaq:MRNA) plans on submitting for regulatory approval for its investigational RSV mRNA-1345 vaccine after it met primary efficacy endpoints in the Phase 3 ConquerRSV study (NCT05127434).

The RSV data are “a clear positive for MRNA” and represent a good omen for upcoming mRNA Phase 3 influenza data, noted UBS in a briefing note.

MRNA shares were up 5.70% in after-hours trading, hitting $201.55.

“Importantly, we think this is a milestone for MRNA’s pipeline beyond COVID in demonstrating the competitive efficacy of mRNA vaccines,” noted UBS Eliana Merle. “We think RSV could be a meaningful opportunity with no vaccine yet approved.

UBS sees an opportunity worth more than $5 billion in RSV.

The Moderna study, enrolling roughly 37,000 adults aged 60 or older in 22 countries, tested mRNA-1345 in older adults divided into two groups. One group had two or more symptoms of RSV-associated lower respiratory tract disease (RSV-LRTD). The other had three or more symptoms.

In the study, vaccine efficacy was 83.7% against RSV-associated lower respiratory tract disease (RSV-LRTD) in participants with two or more symptoms. Vaccine efficacy was 82.4% effective in individuals with three or more symptoms.

An independent Data and Safety Monitoring Board reviewed the data in the ConquerRSV study.

Investigators found the vaccine to be generally well tolerated, identifying no safety concerns. The most common adverse events included injection site pain, fatigue, headache, myalgia and arthralgia.

The ConquerRSV study is ongoing. Moderna anticipates it will be completed by November 30, 2024.

Last November, Pfizer (NYSE:PFE) also revealed positive topline data from the Phase 3 MATISSE clinical trial for its bivalent respiratory syncytial virus (RSV) prefusion vaccine candidate.

Other companies, including Bavarian Nordic (CPH: BAVA), Janssen (NYSE:JNJ) and GSK (NYSE:GSK), are also developing RSV vaccines.

After releasing its latest data, Moderna said it would also submit manuscripts to a peer-reviewed publication. It also plans on presenting it at a scientific meeting.

Moderna intends to continue studying safety and tolerability in an ongoing study.

The company also plans to develop a respiratory combination vaccine to protect against respiratory diseases, including RSV, COVID-19 and influenza. In addition, Moderna is also developing a vaccine for the human metapneumovirus, which can cause upper and lower respiratory illness in people of all ages.

Moderna is also testing mRNA-1345 in an ongoing Phase 1 study in pediatric populations.

The company launched the pivotal trial for its RSV vaccine candidate in February 2022.