Moderna's RSV vaccine catches the fast track on heels of Pfizer's leapfrog into the queue

Moderna has its next act lined up: an mRNA respiratory syncytial virus vaccine, which the FDA has just put on the fast track.

The biotech, which made its name in 2020 with its COVID-19 vaccine, has been granted fast-track designation for mRNA-1345, which is under investigation as a single-dose vaccine for RSV.

Moderna has high hopes for the vaccine to prevent RSV infection in both young children and older adults. RSV typically causes a mild cold-like illness but can be serious in young children and older adults. Infection can cause bronchiolitis and pneumonia and leads to about 177,000 hospitalizations in older adults and 14,000 deaths.

Fast track designations help expedite the review of therapies and vaccines for serious conditions that can fill an unmet need.

RELATED: Moderna's first seasonal flu vaccine slides into clinic as pharma giants crowd into mRNA

Moderna is conducting a phase 1 study of mRNA-1345 spanning children to the elderly to determine tolerability and the vaccine's ability to create antibodies to protect against the virus. Interim results from one month post-vaccination presented in April showed that the vaccine raised neutralizing antibodies compared to baseline at least 11-fold, the company said.

The biotech also plans to investigate mRNA-1345 in combination with its vaccines for other respiratory pathogens in children and separately in adults.

Just one preventative RSV shot, called Synagis, has been approved. The monthly vaccine from Swedish Orphan Biovitrum can be used in high-risk infants. So far a broader protective vaccine has remained elusive, but the pipeline is rich and seems to have hit overdrive in the past few weeks.

While GlaxoSmithKline announced a setback to its RSV program last week, Pfizer jumped in the next day to drop some surprise data from a challenge study that showed the Big Pharma’s candidate was 100% effective in preventing mild-to-moderate symptomatic infection in adults over 50.

RELATED: GSK culls phase 2 RSV vaccine in kids, as feladilimab flops again in lung cancer

GSK abandoned its RSV candidate in children but will move forward with a maternal vaccine test to protect mothers and children during and from birth.

RSV tends to resurface each fall, winter and spring, but over the pandemic, the virus took a break as people around the world locked down and masked up.

But the virus is back with a vengeance now as the U.S. has begun to reopen. Peak infections are now occurring later into the year than usual. RBC Capital analysts said rates are up 30-100 fold compared to the year before, according to a Monday note to clients.

“The seasonal offset observed in the current spike in cases is likely driven by the unique events associated with the pandemic and complicates forecasting for the typical seasonality,” RBC said.

This means that companies with active RSV trials, such as Enanta Pharmaceuticals, are rapidly enrolling volunteers to begin gathering evidence on the effectiveness of their vaccines. Enanta specifically had paused enrollment in three trials of its oral candidate, EDP-938, while RSV laid dormant.

RELATED: Surprise! Pfizer jumps the queue and leaps into RSV vax contention as COVID helps turbo charge work

“Though cases appear to be declining from a relative peak in the past couple of weeks, a lack of pre-existing immunity could drive an even greater surge as older infants and toddlers increasingly come in contact with the virus,” RBC wrote.

With the RSV race heating up, RBC said the market has room for an oral option that could be easier to administer, especially for children who will need the vaccine. 

Sales for Enanta’s candidate could hit $475 million upon approval for use in infants and older adults, RBC estimates.