I would not chase Moderna at $174.38. I would rank the three choices:

1. Merck: best risk/reward

2. Wait for full data: best disciplined approach

3. Moderna: highest upside, but highest valuation risk

The Phase 3 result is genuinely important. INTerpath-001 hit both recurrence-free survival and distant-metastasis-free survival, validating the personalised neoantigen approach in a pivotal trial. 

But Moderna has already repriced the success very aggressively. The market is now capitalising not merely the melanoma indication, but the possibility that this becomes a platform across multiple solid tumours. That is where I would be cautious. Full hazard ratios, subgroup consistency, overall survival, durability, manufacturing economics and regulatory details are still needed. Reuters specifically notes that the detailed clinical data remain pending. 

Merck is more interesting to me. Keytruda is already an enormous commercial franchise, and intismeran potentially extends its oncology lifecycle while adding incremental revenue. Merck also gets the benefit of Moderna's platform without investors having to pay the full "mRNA platform" premium.

There is another reason I would not dismiss Moderna entirely: the Phase 2b foundation was unusually strong, with a sustained 49% reduction in recurrence/death risk after five years. 

So my strategy would be:

Don't chase MRNA after +177%. Hold/watch MRK, and wait for the detailed Phase 3 data before buying Moderna aggressively.

The key question now is no longer "Does the vaccine work?" It is **"How large and economically attractive can this platform become?"**