Shares of Moderna (NASDAQ:MRNA | MRNA Price Prediction) are rocketing higher Wednesday morning, with the stock up 93% to $121.76 in early Wednesday trading after the company and partner Merck (NYSE:MRK) announced that their Phase 3 melanoma trial met its primary endpoint. Merck stock is up 7% to $144.60 on the news.
The catalyst is the first positive Phase 3 readout for a personalized mRNA cancer therapy, an outcome that validates a platform Moderna has spent years building. Moderna shares closed Tuesday at $62.96, down 2% on the session, and the stock has already climbed 114% year to date through Tuesday’s close.
Merck stock closed Tuesday at $135.17 and is up 30% year to date through Tuesday’s close. If early levels hold, Moderna is on track for its biggest ever single-day gain and could open at more than two-year highs.
Phase 3 Melanoma Trial Delivers on Primary Endpoint
The Phase 3 INTerpath-001 trial tested Intismeran Autogene alongside Merck’s immunotherapy Keytruda in patients with high-risk stage IIB-IV melanoma whose tumors had been completely removed by surgery. The combination produced statistically significant and clinically meaningful improvements in recurrence-free survival and in distant metastasis-free survival compared with Keytruda alone.
Enrollment reached 1,137 patients, with two-thirds receiving Intismeran plus Keytruda and the remainder receiving Keytruda alone. No new safety concerns emerged, and the trial will continue to assess overall survival.
Dean Y. Li, President of Merck Research Laboratories, summed up the results succinctly:
These first Phase 3 findings for Intismeran in combination with Keytruda as adjuvant therapy reinforce the promise of a more personalized approach to cancer treatment. We believe individualized neoantigen therapies have the potential to redefine how patients with completely resected stage IIB-IV melanoma are treated.
The results reinforce the earlier Phase 2b Keynote-942 study, where at five years the combination reduced the risk of recurrence or death by 49% and the risk of distant metastasis or death by 59% versus Keytruda alone. The companies are now exploring the approach across nine Phase 2 and Phase 3 trials covering melanoma, lung, bladder, kidney, pancreatic and gastric cancers.
Peers Trade Higher, but the mRNA Read-Across Is Uneven
Pfizer (NYSE:PFE) stock is up 1% to $27.50 in early Wednesday trading, and Pfizer shares are up 15% year to date through Tuesday’s close. The pharma giant benefits indirectly from renewed enthusiasm around oncology combinations, though it has no direct role in the trial.
BioNTech (NASDAQ:BNTX) is the more interesting peer read. Its shares rose 1% Tuesday to close at $92.75 and are down 3% year to date through Tuesday’s close. As the other major mRNA cancer developer, BioNTech has been roughly flat in 2026 while Moderna has run hard, and today’s validation of individualized neoantigen therapy could reset that narrative.
XLV ETF Reflects a Diluted Move
The Health Care Select Sector SPDR Fund (NYSEARCA:XLV) is up 2% to $172.36 in early Wednesday trading, and the ETF is up 11% year to date through Tuesday’s close. As a broad healthcare sector fund holding dozens of large-cap names, any single biotech carries a small weight.
That means Moderna’s outsized jump translates into a modest lift at the fund level, even with Merck’s participation adding weight to the move. Investors seeking direct exposure to mRNA oncology innovation would need the underlying names rather than a diversified sector fund.
What to Watch Next
Retail sentiment on Moderna tracked very bullish heading into the U.S. session, and Moderna options flow is skewed to calls, with the full-chain put/call ratio at 0.46. The Wall Street consensus price target of $50.84 now sits far below the indicated open, so revisions are likely.
The next data checkpoints will come at an upcoming international medical meeting, where the companies plan to present detailed trial results and discuss regulatory submissions. Traders could look for signs that the combination expands into the other tumor types under active study.
Investors may want to keep an eye on whether Moderna shares hold their early gains through the close. A durable move above $120 could confirm a genuine platform re-rating rather than a one-day squeeze.
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