Moderna shares more than doubled after its personalized cancer vaccine cleared a late-stage melanoma trial

Moderna's personalized mRNA cancer vaccine, intismeran, has passed a late-stage clinical trial in melanoma, marking what researchers are calling a first for the field and sending the company's stock surging by more than 145% in a single session.

What the Trial Found

The study, run jointly by @moderna_tx and Merck, enrolled 1,137 high-risk patients with stage 2b to 4 melanoma whose tumors had been surgically removed. Patients were randomized to receive up to nine doses of Keytruda combined with intismeran, or Keytruda alone, over roughly one year. Interim results showed the combination met both its primary goal of reducing cancer recurrence and its secondary goal of preventing the disease from spreading to other parts of the body, compared with Keytruda alone. The companies said no new safety signals emerged during the trial.

Intismeran works by analyzing the unique mutations in each patient's tumor and generating tailored mRNA instructions that help the immune system identify and attack up to 34 different tumor-specific targets. This makes it fundamentally different from conventional cancer therapies, which apply the same treatment regardless of a tumor's individual characteristics. The trial is the first randomized Phase 3 study to produce positive results for any mRNA-based cancer therapy.

Moderna and Merck said they plan to file for regulatory approval within months, though no specific timeline was provided. Moderna President Stephen Hoge said patients who have undergone surgery for high-risk melanoma could benefit as soon as next year.

Market Reaction and What Comes Next

$MRNA shares surged more than 145%, rising from a previous close of $62.96 to trade at $158.29, touching an intraday high of $163. The move left short sellers facing roughly $5 billion in losses, according to Bloomberg. Merck shares also climbed more than 10% on the news.

J.P. Morgan analysts said the commercial launch of intismeran in adjuvant melanoma will be critical to Moderna returning to profitability. William Blair analysts called the data "a clear positive for shares and Moderna's fundamental business." The treatment remains unapproved and the companies released only initial results from the ongoing study.

Sources:
STAT News: Moderna and Merck say mRNA cancer vaccine succeeded in late-stage melanoma trial
CNBC: Moderna, Merck cancer vaccine shows promise in late-stage trial
CNN: Moderna and Merck say melanoma vaccine succeeded in large trial