Moderna Stock Doubles, Adding $26.4 Billion After Cancer Vaccine Meets Both Phase 3 Goals

Moderna stock more than doubled at its premarket peak Wednesday after the company’s personalized mRNA cancer treatment, developed with Merck, succeeded in a pivotal Phase 3 melanoma trial.

MRNA rose by approximately 105% from Tuesday’s $62.96 closing price, reaching an estimated peak near $129.07. The stock later traded around $122.19, representing a gain of 94.08%.

Merck shares also advanced approximately 7.5% as investors assessed the commercial implications for Keytruda, the company’s blockbuster cancer treatment.

The rally pushed Moderna shares to their highest level in roughly two years and represented one of the company’s largest price moves since the COVID-19 pandemic. Premarket gains differed slightly across market-data providers because the stock remained highly volatile.

Moderna Temporarily Adds $26.4 Billion in Market Value

Moderna had approximately 399.24 million outstanding shares and a market capitalization of $25.14 billion before the trial announcement.

At the estimated $129.07 premarket peak, each share had gained approximately $66.11. Multiplying that increase by the outstanding share count indicates that Moderna temporarily added about $26.4 billion to its market value.

That placed its implied capitalization near $51.5 billion.

At the later price of $122.19, the increase was approximately $23.6 billion, giving Moderna an implied market value of roughly $48.8 billion.

These calculations represent changes in stock-market valuation—not cash received by Moderna. The totals can also change considerably as the stock moves during premarket and regular trading.

Cancer Treatment Meets Both Major Phase 3 Goals

The ongoing Phase 3 INTerpath-001 trial evaluated Moderna’s intismeran autogene, also known as V940 or mRNA-4157, in combination with Merck’s Keytruda.

The study included 1,137 patients whose high-risk stage IIB-IV melanoma had been surgically removed.

Intismeran is not a conventional preventive vaccine. It is an experimental individualized neoantigen treatment manufactured using mutations identified within each patient’s tumor. The therapy is intended to train the immune system to recognize and attack cancer cells carrying those mutations.

Patients received either intismeran plus Keytruda or Keytruda alone. An interim analysis found that the combination produced statistically significant and clinically meaningful improvements in:

• Recurrence-free survival, which measures how long patients remain alive without their cancer returning.
• Distant metastasis-free survival, which measures how long patients avoid the cancer spreading to distant parts of the body.

The companies reported no new safety signals. They plan to present detailed results at a medical conference and discuss potential regulatory submissions with health authorities.

Overall-survival monitoring is continuing. Therefore, the announcement does not yet prove that the combination helps patients live longer than Keytruda alone.

Phase 3 Effect Sizes Have Not Been Disclosed

Moderna and Merck have not released the Phase 3 hazard ratios, complete numerical results or detailed safety data.

The frequently reported 49% reduction in the risk of recurrence or death and 59% reduction in distant metastasis or death came from the smaller Phase 2b study, not the new Phase 3 trial.

Those earlier figures should not be presented as Phase 3 results. The magnitude of the benefit observed in the larger study will remain unknown until the companies release the complete data.

Why Moderna Stock Reacted So Sharply

The result represents a major late-stage validation of an individualized mRNA cancer treatment and provides evidence that Moderna’s technology could produce commercially important products beyond respiratory vaccines.

The Financial Times described the result as the first success of its kind in a late-stage trial for an mRNA cancer therapy. However, regulatory approval has not yet been granted.

Barclays previously estimated that intismeran could generate approximately $3 billion in annual melanoma sales by 2035. The potential market could become larger if ongoing studies establish benefits in lung, bladder, kidney and other cancers.

Short covering may also have amplified the rally. Published data showed that approximately 52.4 million Moderna shares, representing about 14.8% of its public float, were sold short as of July 15.

A sudden doubling in the stock can force bearish traders to buy shares to close their positions. However, real-time short-position data are unavailable, so it is impossible to determine how much of Wednesday’s rally resulted from short covering.

MRNAon Surges With Moderna Stock

MRNAon, Ondo Finance’s tokenized version of Moderna stock, also surged following the Phase 3 announcement.

CoinMarketCap showed MRNAon trading near $118.80, up approximately 87.2% over 24 hours. The token reached a record high of $124.39, while reported trading volume climbed to approximately $230,000.

MRNAon had a circulating supply of only about 842 tokens and a token market capitalization near $100,000. That figure represents the value of circulating MRNAon tokens—not Moderna’s corporate market capitalization.

The token’s limited supply and liquidity mean its price can temporarily differ from Nasdaq-listed MRNA, particularly during periods of extreme volatility.

Verdict for MRNA and MRNAon

The Phase 3 success substantially reduces the scientific risk surrounding Moderna’s cancer platform and confirms that the promising Phase 2b results were not confined to a small study.

Nevertheless, several uncertainties remain. Moderna and Merck must disclose the size of the Phase 3 benefit, complete safety findings and eventually overall-survival data. Regulatory approval, commercial pricing and the challenge of manufacturing individualized treatments at scale also remain important.

The result is potentially transformative for Moderna. However, a stock gain exceeding 100% means investors have already priced in considerable confidence that intismeran will secure approval and become a multibillion-dollar cancer treatment.