Shares of Moderna surged as much as 104.8% to $128.92 Wednesday after the company and partner Merck announced that their personalized mRNA cancer vaccine hit both primary and secondary goals in a pivotal late-stage trial — the first randomized Phase 3 clinical trial aimed at definitively proving the benefit of so-called "neoantigen" vaccines. The result instantly reframed Moderna from a shrinking COVID-vaccine company into a potential oncology player, but the stock's new implied market cap of roughly $50 billion demands scrutiny against a business still running deep in the red.
A First-of-Its-Kind Win, but Key Numbers Are Missing. The trial enrolled 1,137 patients with surgically removed high-risk melanoma and showed "statistically significant and clinically meaningful" improvements in recurrence-free survival and distant metastasis-free survival. However, the topline release lacks effect sizes, mature survival data and a regulatory timetable.
Citi analysts had set a hazard ratio at or below 0.65 — meaning a 35% risk reduction — as a "clear win," but investors are flying blind until the full dataset is presented at a medical conference.
The Revenue Gap Is Still Enormous. Moderna's 2025 revenue was $1.9 billion, largely from COVID vaccine sales.
The company is spending roughly $3 billion on research this year and remains unprofitable. Analysts estimate an approved cancer vaccine could generate more than $6 billion in annual sales in melanoma alone, with additional upside if the approach works in lung, kidney, and bladder cancers. But approval, manufacturing scale-up, and launch could take years — Moderna sought accelerated approval for this vaccine in 2024 and was rebuffed by the FDA.
Making a Custom Drug for Every Patient Is Hard. Personalized manufacturing may complicate cost, capacity and access. Each dose is tailored to a patient's tumor DNA, coding for up to 34 unique targets. Scaling that from a 1,137-patient trial to tens of thousands of commercial patients is an unproven industrial challenge that will directly determine profit margins.
The Market Is Pricing In More Than Melanoma. Analysts said the company's valuation already reflected expectations that the vaccine could eventually work across multiple types of cancers before Wednesday's stock move.
Merck and Moderna are studying the vaccine in several trials across other tumors, such as non-small cell lung cancer, bladder cancer and renal cell carcinoma. With shares having fallen 85% over the five years before Wednesday's announcement, the doubling prices in a future that remains clinically and commercially unproven.