Moderna launches pivotal trial for mRNA RSV vaccine

The Data and Safety Monitoring Board for Moderna’s (NASDAQ:MRNA) respiratory syncytial virus (RSV) vaccine program has backed the launch of a Phase 3 clinical study of the mRNA-1345 vaccine candidate.

The study will focus on adults 60 years and older.

RSV leads to approximately 177,000 hospitalizations and 14,000 deaths among adults aged 65 years or older, according to CDC.

The Phase 3 trial will enroll roughly 34,000 volunteers internationally in the trial, known as ConquerRSV.

There are currently no authorized RSV vaccines available.

“We believe that our vaccine candidate against RSV has the potential to protect against over 1 million infections globally each year, improving quality of life for those at high risk of becoming infected and reducing the burden on health care systems.”

Jacqueline Miller

“RSV is one of the most widespread respiratory viruses, causing severe disease and hospitalization in older adults, and yet there is no vaccine available on the market,” said Stéphane Bancel, Moderna CEO, in a statement.

The mRNA-1345 vaccine candidate encodes for a prefusion F glycoprotein.

Moderna notes that the perfusion F glycoprotein elicits a superior neutralizing antibody response than the postfusion state. “The RSV F protein is highly conserved amongst RSV strains, and therefore is a good choice for an RSV vaccine candidate,” said Jacqueline Miller, senior vice president, therapeutic area head, infectious diseases at Moderna. “The RSV F protein mediates both viral entry and cell-to-cell spread and is critical for propagating RSV infection. There are two forms of the RSV protein: pre-fusion and post-fusion. Antibodies to the pre-fusion form have the highest neutralizing activity.”

The FDA has granted fast track designation for mRNA-1345 in adults 60 and older last year.

Moderna is also exploring the development of a booster vaccine that targets RSV, flu and COVID-19.

Pfizer (NYSE:PFE), Johnson & Johnson (NYSE:JNJ), GlaxoSmithKline (LON:GSK), Novavax (NSDQ:NVAX) and Bavarian Nordic (CPH:BAVA) are also working on RSV vaccines.