Big promise of personalised mRNA cancer vaccine: Death risk down dramatically

Covered by Bloomberg Business, Morningstar and 9 more since

  • Merck & Co.
  • Moderna
A gloved hand holds a small clear vaccine vial in a bright, modern laboratory with blurred equipment behind it.

What happened

A personalized mRNA melanoma vaccine from Moderna and Merck, called intismeran, cut the risk of cancer returning or death by 42% when added to the immunotherapy Keytruda after surgery. The Phase 3 trial of 1,137 patients was presented Oct. 24 in Madrid. Whether it helps people live longer is not yet known, and approval is expected in 2027.

Summary

For people whose high-risk melanoma has been surgically removed, a vaccine built from their own tumor may lower the chance the cancer comes back. In the Phase 3 INTerpath-001 trial, 1,137 patients with stage IIB to IV skin melanoma got Keytruda plus either intismeran or a placebo. Adding the vaccine cut the risk of recurrence or death by 42%. After two years, 82.2% of patients on the combination were alive and cancer-free, compared with 70.0% on Keytruda alone. The risk of the cancer spreading to distant parts of the body, or death, fell by 38%. [4] [5] [7] [10] [11]

Georgina Long of Melanoma Institute Australia, the study's global principal investigator, presented the results Oct. 24 at the European Society for Medical Oncology meeting in Madrid. "It's a penicillin moment," she said. The vaccine reads a tumor's genetic makeup to find neoantigens, abnormal proteins unique to that cancer, then uses mRNA to teach the immune system to attack them. It is a treatment for people who already have cancer, not a preventive shot. Overall survival data are still early and show no statistically significant difference yet. Fever, injection-site pain and fatigue were the most common side effects, and those tied to the injections were generally mild and brief. [5] [7] [10] [11]

The detailed data leaked before the presentation because an embargo was broken. Moderna shares fell 18% on Oct. 22 as analysts focused on a smaller benefit against distant spread, and they dropped about 7% more on Monday. Moderna CEO Stéphane Bancel told STAT the companies are racing to file for FDA approval, which he expects in 2027. Analysts and doctors say open questions remain: whether the approach works in other cancers, how it compares with giving immunotherapy before surgery, and how to make each vaccine individually. Trials are already under way in lung, bladder and kidney cancer. [2] [6] [7] [8] [10]

Summary written by Vox Populi News from the 11 sources below. See all sources

Key questions

Does the melanoma vaccine help patients live longer?

It is too soon to say. Overall survival data were still immature at this analysis and showed no statistically significant difference, and researchers are continuing to follow patients. [5] [7] [10]

Can healthy people get this vaccine to prevent melanoma?

No. Intismeran is made individually for each patient from their own tumor, and it is meant to help clear leftover cancer cells after surgery, not to prevent cancer in people without it. [5] [7] [11]

When could intismeran be approved?

Moderna CEO Stéphane Bancel said he expects FDA approval in 2027, though experts note timing is uncertain and manufacturing costs could affect access. [5] [6]

Sources 11

  1. 1Bloomberg Business

    How Melanoma Became the Proving Ground for a Personalized Cancer Vaccine

    Study findings validate a novel approach for fighting deadly skin cancer, while its potential in other tumors remains unproved A few months ago, Georgina Long received a message asking her to call a…

    Jason Gale

    Read on Bloomberg Business (opens in a new tab)
  2. 2Morningstar

    The excitement around Moderna's cancer vaccine is cooling. Here's why.

    Investors had 'incredibly high' expectations around the Phase 3 data for the drugmaker's experimental cancer treatment Moderna's stock is down as investors digest the highly anticipated Phase 3…

    Read on Morningstar (opens in a new tab)
  3. 3Investor's Business Daily

    Moderna Recovers, But Muted Expectations Haunt Cancer Vaccine

    Moderna (MRNA) stock wavered Monday on more muted expectations for its Merck (MRK)-partnered cancer vaccine following Saturday's presentation at the European Society of Clinical Oncology Congress.

    Allison Gatlin

    Read on Investor's Business Daily (opens in a new tab)
  4. 4Inc.

    This Breakthrough Cancer Treatment Can Cut Risk by 42 Percent

    A groundbreaking phase 3 clinical trial reveals that a personalized mRNA vaccine from Merck and Moderna significantly cuts the risk of melanoma returning.

    Sage Swaby

    Read on Inc. (opens in a new tab)
  5. 5New Atlas

    Landmark melanoma vaccine cuts deaths in landmark trial

    The results of a landmark cancer vaccine trial demonstrate the power of treatments tailored to the person receiving them, hinting at a future where cancer treatments are personalized to seek out…

    Science Photo Library

    Read on New Atlas (opens in a new tab)
  6. 6STAT

    Five biotech updates to read after ESMO this weekend

    Moderna's vaccine possibility, another autoimmune CAR-T death, and more biotech news Soundtrack at present: Iggy Pop, The Idiot.

    Meghana Keshavan

    Read on STAT (opens in a new tab)
  7. 7News-Medical.net

    Personalized mRNA cancer vaccine cuts melanoma recurrence risk when added to immunotherapy

    European Society for Medical Oncology (ESMO)Oct 24 2026Reviewed Adding a personalized mRNA-based cancer vaccine to immunotherapy after surgery for high-risk melanoma reduced the risk of recurrence or…

    Read on News-Medical.net (opens in a new tab)
  8. 824/7 Wall St.

    Moderna Tumbles 7% as Cancer Vaccine Selloff Deepens; BioNTech Falls 3%, Pfizer Holds Steady

    A closely tracked personalized melanoma vaccine met its main goal. Its effect on distant spread came in far smaller than an earlier study suggested in a late-stage trial.

    David Moadel

    Read on 24/7 Wall St. (opens in a new tab)
  9. 9The Columbian

    New vaccine ushers in hope for cancer patients

    An experimental vaccine developed by Merck and Moderna could become the first vaccine of its kind used to treat cancer. Scientists hope it won't be the last.

    Read on The Columbian (opens in a new tab)
  10. 10Advisor Perspectives

    How Melanoma Became the Proving Ground for a Personalized Cancer Vaccine

    A few months ago, Georgina Long received a message asking her to call a collaborator at Merck & Co. She feared the worst.

    Read on Advisor Perspectives (opens in a new tab)
  11. 11Knowridge Science Report

    Personalized skin cancer vaccine cuts recurrence or death risk by 42%

    A vaccine designed around each patient's own melanoma reduced the relative risk of cancer returning or death by 42% when added to immunotherapy after surgery, according to results from a large…

    Read on Knowridge Science Report (opens in a new tab)