The latest

Moderna shares surged 177% on Wednesday, the largest one-day gain by an S&P 500 company in more than two decades, after the drugmaker and Merck announced successful late-stage results for a personalized mRNA melanoma vaccine. Moderna’s market value ended the week near $60 billion, up from about $25 billion before the announcement. Together, Moderna, Merck and BioNTech, which is developing its own personalized mRNA cancer vaccine, added roughly $80 billion in market capitalization within days.

Details

• Trial outcome: Moderna and Merck said patients receiving the vaccine with Keytruda were significantly less likely to experience melanoma recurrence than those given Keytruda alone. The companies will present the data at an upcoming conference. The study is the first late-stage validation of an mRNA cancer vaccine and supports Moderna’s broader cancer-vaccine platform.
• Sales outlook: Daina Graybosch of Leerink Partners models annual sales in the low single-digit billions by 2032. In a bullish scenario with $10 billion in peak annual partnership sales, she estimates the therapy could support about $40 billion in added value for Moderna and Merck combined—less than the market added in one afternoon.
• Melanoma advantage: The vaccine sequences a patient’s tumor, selects up to 34 mutations and trains the immune system to recognize them. Graybosch said typically only two or three targets produce a meaningful response. Melanoma’s abundance of mutations provides more targets, while its sensitivity to immunotherapy improves the chance of an immune response.
• Harder cancers: Kidney cancer offers fewer mutations to target, while bladder cancer has a more suppressive tumor environment. Pancreatic cancer is notoriously resistant to immune-based treatment. Those biological differences leave open whether success in melanoma can extend across the next tumors pursued by Moderna and Merck.
• Production economics: Unlike drugs made in bulk, each dose requires surgery to remove a tumor, laboratory sequencing and algorithmic selection of vaccine targets. Based on comparable therapies, a full course could cost around $300,000. European health systems negotiate aggressively, while Trump administration policies seek to link US prices more closely to those in other wealthy countries.
• Margin limits: Graybosch estimates initial gross margins of 50% to 80%, well below the more than 90% possible for conventional drugs. RBC Capital Markets analyst Luca Issi said investors are pricing a possibility that the vaccine could resemble Keytruda or Opdivo, checkpoint therapies effective across multiple cancers, rather than remain useful in a narrower group of tumors.

Between the lines

The bigger mRNA opportunity may be cancer prevention in people at high risk before disease takes hold, which Graybosch described as a vaccine in the truest sense. That possibility could be transformative, but remains far from clinical use.

What’s next

Moderna and Merck will next present the full melanoma trial data at an upcoming conference; kidney and bladder cancer studies will provide the next tests of whether the platform can work beyond melanoma.