Moderna and Merck's personalized mRNA cancer vaccine intismeran autogene met its primary endpoint in the Phase 3 INTerpath-001 trial, reducing melanoma recurrence risk versus Keytruda alone. Moderna shares surged 177 percent, adding roughly $44 billion in market value, in the first positive Phase 3 readout for an individualized neoantigen therapy.
Moderna and Merck's experimental mRNA cancer therapy met its main goal in a Phase 3 melanoma study, sending Moderna shares up 177 percent.
"The results represent a landmark moment for adjuvant melanoma treatment," Georgina Long, the trial's principal investigator and a researcher at Melanoma Institute Australia, said. "This is the first Phase 3 study to show that intismeran, a treatment designed based on the unique mutational fingerprint of a patient's own tumor, given in combination with pembrolizumab can reduce the risk of recurrence or death."
The INTerpath-001 trial enrolled 1,137 patients with completely resected stage 2B to 4 melanoma, randomized 2-to-1 to receive intismeran autogene (V940/mRNA-4157) plus Keytruda or Keytruda alone. The combination achieved statistically significant improvements in both recurrence-free survival and distant metastasis-free survival. Earlier Phase 2b data from KEYNOTE-942 showed the combination cut recurrence or death risk by 49 percent and distant metastasis or death risk by 59 percent at five years.
Moderna shares surged 177 percent in a single day, adding approximately $44 billion in market value, the largest single-day gain since the company's IPO. Combined with Merck, the two companies added more than $50 billion in market value.
The clinical success also lifted oncology sequencing stocks. Tempus AI, which confirmed it would serve as sequencing partner if the vaccine receives regulatory approval, rose 24 percent in the weeks following the data release. Piper Sandler estimates the vaccine could generate at least $50 million in annual sequencing revenue for melanoma alone, while BTIG analyst Mark Massaro projects more than $600 million if the therapy expands to lung, bladder and kidney cancers.
The result has complicated Tempus AI's pending $1.5 billion acquisition of Personalis, the sequencing partner for Moderna's clinical programs. Personalis shares climbed to $18, above Tempus AI's $16.25 per share offer, fueling speculation of a higher bid. Proxy filings revealed Personalis received a verbal offer of $17 per share from another buyer before agreeing to Tempus AI's terms.
Clinical risk in personalized cancer vaccines remains unresolved. One week after Moderna's positive readout, BioNTech terminated a Phase 2 trial of its personalized mRNA vaccine autogene cevumeran in colorectal cancer after an independent data safety monitoring board identified more deaths in the vaccine arm. Moderna's success was aided by melanoma's high immunogenicity and abundant neoantigens, while BioNTech faced a more challenging "cold tumor" indication.
The companies plan to present full results at an upcoming international meeting and engage with regulators on approval submissions. Intismeran autogene is also being studied in nine Phase 2 and Phase 3 trials spanning non-small cell lung, bladder, kidney, pancreatic and gastric cancers.
The Phase 3 success confirms the mRNA platform's reach beyond infectious disease vaccines into oncology, where each dose is manufactured individually based on a patient's tumor sequencing. Investors will watch for regulatory submission timelines and whether Moderna can replicate the result across additional tumor types.
This article is for informational purposes only and does not constitute investment advice.
