With no filing yet, can the FDA approve Moderna's vaccine?

Moderna's stock nearly doubled on Wednesday after Merck and Moderna announced that their Phase 3 melanoma trial, INTerpath-001, hit both its main endpoints at a planned interim look. Polymarket's skin cancer vaccine market opened the same afternoon at 72.5 cents for the FDA approving the shot by December 31, 2027. Here's why we are betting against that to capture 257% in 16 months.

The contract resolves on one document: an FDA approval letter for intismeran autogene, the individualized therapy also known as mRNA-4157.

So the question is not whether the drug works. It is whether an application nobody has written yet can be filed, reviewed and signed inside 16 months.

Nothing has been submitted. The two companies said on Wednesday they will engage with regulators on filings. Stéphane Bancel, Moderna's chief executive, said the medicine could be approved as soon as 2027, depending on the review.

The problem is that the last time they asked the agency to move fast, Moderna told investors in September 2024 that early feedback had not been supportive of an accelerated path.

Many traders are reaching for the Keytruda precedent, which went from melanoma results to approval in about 10 months in 2019. But that was a supplement to a medicine the FDA had already licensed, made in a plant it had already inspected.

On the other hand, Intismeran needs an original license, and every dose is built for one patient out of as many as 34 targets, in a Massachusetts factory that only began supplying clinical batches in September 2025 and has never been inspected for commercial use.

Priority review of an original application runs about eight months, and two of those are the agency deciding whether the file is even complete. The submission has to land by roughly the middle of next year for the calendar to work.

Not to mention, the most important fact is that the trial itself is not even scheduled to finish until October 2029.