Investors were awaiting full data from the late-stage trial of intismeran autogene plus Merck’s Keytruda at the European Society for Medical Oncology Congress on October 24.

  • ESMO on Thursday confirmed in a post on X that the embargo on the study data has been “breached.” 
  • Merck and Moderna subsequently unveiled the full data. 
  • The companies said that the combination of the vaccine and Keytruda reduced the risk of cancer recurrence or death by 42% compared to Keytruda alone in the trial after a media follow-up of 24.6 months.

Shares of Moderna (MRNA) slumped about 18% on Thursday after the company’s trial data on its melanoma vaccine, slated to be announced over the weekend, leaked and fell short of elevated Wall Street expectations.

In August, Moderna announced that the late-stage trial of its cancer vaccine intismeran autogene plus Merck’s Keytruda had met its primary endpoint of recurrence-free survival in patients with resected high-risk melanoma. The trial also met a key secondary endpoint of improvement in distant metastasis-free survival, or the length of time after cancer treatment during which a patient does not develop cancer that has spread to distant organs or die. Investors were awaiting full data at the European Society for Medical Oncology (ESMO) Congress on October 24.

MRNA, MRK Trial Data Breach

ESMO on Thursday confirmed in a post on X that the embargo on the study data has been “breached.”

“As the data are now publicly available, ESMO has released the information contained in the abstract and has lifted the embargo on the full dataset,” ESMO said.

According to a report from Barron’s, details of the trial were published on the website Oncology Central and later pulled. Merck and Moderna subsequently unveiled the full data.

Companies Release Full Data

Merck and Moderna said that the combination of the vaccine and Keytruda reduced the risk of cancer recurrence or death by 42% compared to Keytruda alone in the trial after a media follow-up of 24.6 months. The combination also reduced the risk of distant cancer metastasis or death by 38% compared to Merck’s drug alone, the companies added.

The companies also said that a favorable overall-survival trend was observed with the combination, though the data is yet to mature. Overall survival refers to the time from diagnosis or start of treatment until the patients’ demise. The study is still ongoing with no new safety signals identified, the companies said.

An earlier trial had found that the combination reduced the risk of disease recurrence or death by 49% and the risk of distant metastasis or death by 59%. The study involved a different group of patients.

Wall Street Weighs In

TD Cowen said earlier today, after the data was leaked, that while it is compelling and favorable, it is below elevated expectations. The firm has a 'Hold' rating on Moderna with a $90 price target, implying a potential downside of over 50% from the stock’s last closing price.

Wells Fargo, which has an 'Overweight' rating and a $165 price target on Merck, meanwhile, said that the data concerns “maybe overdone” and recommended buying MRK shares on weakness.

Bernstein, meanwhile, termed the MRNA selloff a “sell the news event.”

How Did MRNA, MRK Retail Traders React?

On Stocktwits, retail sentiment for MRNA stock fell from 'neutral' to 'bearish' territory over the past 24 hours, while message volume stayed at 'high' levels.

Meanwhile, sentiment around MRK fell from 'bullish' to 'neutral' territory, coupled with 'normal' retail chatter.

A Stocktwits user pinned the MRNA stock drop to the data being not as good as expected.

View this Stocktwits post

Another user highlighted that the vaccine only reduces the risk of cancer but is not a cure.

View this Stocktwits post

While MRNA stock has gained about 600% year-to-date, MRK has added 40%. 

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