Moderna shares plunge 25% after leak of cancer vaccine data, despite positive results
Moderna and Merck shares fell after partial data leaked, but full phase 3 results showed the personalized vaccine with Keytruda cut melanoma recurrence risk by 42%.
At a glance
- Moderna shares fell as much as 25% Thursday after partial data on its cancer vaccine with Merck leaked ahead of full release.
- The personalized vaccine plus Keytruda cut melanoma recurrence or death risk by 42% versus Keytruda alone in phase 3 trial.
- Analysts called the data positive but said the stock drop reflected inflated expectations; Moderna shares are up over 530% this year.
Moderna shares dropped as much as 25% on Thursday after partial data on its closely watched cancer vaccine, developed with Merck, leaked ahead of a medical conference. Shares of both drugmakers fell even though the full data, released later Thursday, appeared meaningful for patients and positive relative to Wall Street expectations.
The personalized vaccine, called intismeran autogene, paired with Merck's immunotherapy Keytruda reduced the risk of recurrence or death in certain melanoma patients by 42% compared with Keytruda alone. The combination also reduced the risk of cancer spreading to distant parts of the body or death by 38%.
About 82% of patients who received the vaccine alongside Keytruda were alive without their melanoma returning at two years, compared with 70% of those who received Keytruda alone.
"This is a huge development for our patients," said Dr. Hussein Tawbi, a melanoma expert and trial investigator at the University of Texas MD Anderson Cancer Center. He said the added benefit comes with much milder toxicity, such as injection-site pain, compared with other cancer treatments.
The detailed phase 3 trial results were set to be presented at the European Society for Medical Oncology conference this weekend.
Analyst and company reaction
"Whenever you put a therapy on top of something that works really well, like Keytruda, sometimes it's harder to show additional benefit. We have no problems of showing additional benefit here," Dr. Dean Li, Merck Research Laboratories president, said in an interview ahead of the results.
A separate analysis showed a 58% reduction in risk of recurrence or death after the six-month vaccine regimen. The companies said it is still too early to determine whether the treatment helps patients live longer overall.
BMO Capital Markets analyst Evan Seigerman said in a research note that the relative reduction in recurrence and death is "clinically meaningful." He added that the stock reaction "likely reflects inflated expectations into the full data release, rather than a true indictment on the efficacy of the combo therapy."
UBS analysts called it "overall a strong data set" and said it gives more confidence in upcoming studies of the vaccine in kidney and bladder cancers.
Broader potential
Oncologists and investors see the targeted vaccine as a possible breakthrough, with potential use in other cancers. Merck and Moderna are studying it in non-small cell lung cancer, bladder cancer and renal cell carcinoma. But Li cautioned: "I can dream of creating a log cabin, but we got some wood chops, and we've just knocked down one tree. Knocking one tree does not give you a cabin or a village."
The shot is designed to target specific mutations in each patient's tumor, training the immune system to recognize and kill unique cancer markers, then pairing that response with Keytruda.
It could offer Moderna another commercial product after its Covid-19, flu and RSV vaccines. Moderna shares have spiked more than 530% year-to-date as of Thursday afternoon. Merck shares fell about 1% on Thursday and have climbed nearly 41% this year.
Since the vaccine is personalized, manufacturing can take six weeks. Merck CEO Robert Davis told CNBC last week that the company believes it can shorten that timeline, potentially reaching more patients more quickly.
Source: CNBC Top News.
Questions and answers
- Why did Moderna shares drop despite positive cancer vaccine data?
- Shares fell as much as 25% after partial data leaked, but analysts said the reaction likely reflected inflated investor expectations rather than disappointing results.
- How effective is Moderna and Merck's cancer vaccine?
- In a phase 3 trial, the personalized vaccine with Keytruda reduced the risk of melanoma recurrence or death by 42% compared with Keytruda alone, and 82% of patients were alive without recurrence at two years.
- What cancers is the vaccine being tested in?
- Merck and Moderna are studying it in non-small cell lung cancer, bladder cancer and renal cell carcinoma, in addition to melanoma.
