The market has just witnessed one of the most significant events in modern oncology. Moderna (MRNA) shares surged more than 100% in pre-market trading, reaching $122.51. The reason is the successful Phase 3 trial results of a personalized mRNA cancer vaccine developed in partnership with Merck (MRK).
The explosive growth has so far only been recorded in over-the-counter trading. On Tuesday, Moderna shares closed at $62.96, so the morning surge effectively doubled the company's market capitalization before the main session even opened.
First-ever success of personalized mRNA therapy
This concerns the INTerpath-001 study, which tested a fundamentally new approach. Doctors analyzed mutations in each individual patient's tumor, after which Moderna created a personalized vaccine encoding up to 34 tumor targets — so-called neoantigens. In essence, the drug trains the immune system to precisely attack the cells that pose a threat to that specific person.
The study involved 1,137 patients with stage IIB–IV melanoma after surgical removal of the tumor. The results are impressive: the combination of the vaccine with Merck's Keytruda (the standard of care) significantly increased the recurrence-free period compared to Keytruda monotherapy. Moreover, the combination slowed the spread of cancer throughout the body.
This is particularly important because no agent had previously outperformed Keytruda in adjuvant therapy. As Moderna CEO Stéphane Bancel stated, this is a "turning point for oncology," since the idea of creating a vaccine for a specific patient seemed unattainable until recently. The safety profile remained unchanged — no new serious side effects were identified.
Outlook for Moderna shares: from peak to resurgence
It is worth recalling that few stocks have fallen as hard as Moderna. In August 2021, shares traded above $480 amid the wave of COVID vaccine sales, but then lost more than 90% of their value. The recovery began even before this news: in 2026, the stock had already more than doubled thanks to the approval of a flu vaccine and the expansion of its product portfolio.
On Wednesday, shares briefly rose to nearly $130, closing around $122. Merck shares also gained about 6%. However, caution remains: detailed data on efficacy and overall survival have not yet been published, and the companies only plan to present full results at medical conferences and discuss them with regulators.
The same drug combination is currently being tested in nine studies against lung, bladder, and kidney cancers. The key question for investors is whether the morning surge can hold after the market opens.
My view: This is not just an ordinary success, but a paradigm shift. If the data are confirmed, mRNA technology will get a second wind, and Moderna will transform from a "post-COVID disappointment" into a leader in personalized medicine. However, volatility will be high, and investors should wait for the full data publication before making long-term decisions.