The Food and Drug Administration (FDA) notified Moderna Inc ( MRNA ) on Friday that its review of a new vaccine has been delayed.

The agency, citing administrative constraints, does not expect to complete its review of the Biologics License Application (BLA) for mRNA-1345, Moderna’s investigational respiratory syncytial virus (RSV) vaccine, by the Prescription Drug User Fee Act date of May 12, 2024. 

The FDA has informed Moderna ( MRNA ) that it is working to conclude the review by the end of May 2024.

The FDA has not informed Moderna ( MRNA ) of any issues related to vaccine safety, efficacy, or quality that would prevent the approval of mRNA-1345.

Related: Moderna Reports Smaller Than Expected Q1 Loss, Prepares For RSV Vaccine And Spikevax 2024-2025 Formula, Stock Soars.

Moderna ( MRNA ) remains on track for mRNA-1345 to be reviewed at the CDC’s Advisory Committee on Immunization Practices June 26-27, 2024, meeting, which is necessary before commercial launch.

In February, Moderna ( MRNA ) released a longer-term trial analysis that showed a faster decline in the effectiveness of its experimental RSV vaccine.

Follow-up data from the Phase 3 mRNA-1345 Trial At ReSViNET suggests the vaccine efficacy is declining faster than RSV vaccines from GSK Plc ( GSK )   and Pfizer Inc ( PFE ) .

The data showed that the efficacy of the mRNA-1345 vaccine was about 63% after 8.6 months, from 84% at 3.3 months.

Top-line data released a year ago showed that mRNA-1345 demonstrated vaccine efficacy of 83.7% against RSV lower respiratory tract disease.

William Blair writes that although regulatory delays are disappointing and usually create noise around the probability of approval, the update on Moderna’s RSV vaccine does not alter the expectation that mRNA-1345 will receive approval under the current review cycle. 

Management has pinned the RSV vaccination target addressable market at about $10 billion.

The analyst models $1.46 billion in peak U.S. sales for mRNA-1345.

“The product remains an important contributor to Moderna’s return to growth in 2025 and 2026 breakeven story,” William Blair writes.  

The analyst reiterates the Market Perform rating on Moderna ( MRNA ) shares.

Price Action: MRNA shares are down 2.20% at $119.99 during the premarket session at last check Friday.

Now Read: Moderna Reports Smaller Than Expected Q1 Loss, Prepares For RSV Vaccine And Spikevax 2024-2025 Formula, Stock Soars

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