Moderna Stock Soars More Than 100% on Cancer Vaccine Breakthrough: What Investors Are Betting On

Moderna shares more than doubled on Wednesday after the company and Merck said their personalised mRNA cancer treatment met its primary and key secondary goals in a late-stage melanoma trial.

The Phase 3 INTerpath-001 trial evaluated intismeran autogene in combination with Merck's Keytruda in patients with completely resected stage IIB to IV melanoma, compared with Keytruda alone. The study met its primary endpoint of recurrence-free survival and a key secondary endpoint of distant metastasis-free survival, according to the companies.

Moderna shares rose as much as about 150% during intraday trading, while Merck also gained. The companies said they released topline results and have not yet disclosed full data from the study, including detailed efficacy measures and overall survival results.

Why the Melanoma Result Matters to Moderna

The trial enrolled 1,137 patients whose melanoma had been surgically removed but who remained at high risk of recurrence or metastasis.

According to Moderna and Merck, the combination of intismeran and Keytruda showed statistically significant improvements in both recurrence-free survival and distant metastasis-free survival compared with Keytruda alone. No new safety signals were reported.

The result follows earlier-stage evidence from the Phase 2b KEYNOTE-942 study, presented in June, which showed that intismeran plus Keytruda reduced the risk of recurrence or death by 49% and reduced the risk of distant metastasis or death by 59% compared with Keytruda alone.

The Phase 3 study is a larger confirmatory trial of the same treatment approach. The companies have not yet provided full data from the study.

What Investors Are Reacting To

The share price move followed the announcement of positive topline results from the Phase 3 trial.

A successful outcome in melanoma could support regulatory submissions for the combination therapy, subject to review by health authorities.

Analysts cited by Reuters said the data could support potential regulatory filings, with a possible launch timeline as early as 2027.

Regulatory approval has not yet been granted, and the companies have not submitted full trial data to regulators.

Intismeran is also being studied in other tumour types, including non-small cell lung cancer, bladder cancer and renal cell carcinoma, as part of Moderna's oncology development programme.

About the Treatment

Intismeran autogene is an investigational personalised mRNA therapy designed to target neoantigens derived from mutations in an individual patient's tumour.

After surgical removal of a tumour, genetic sequencing is used to identify tumour-specific mutations. The treatment is then designed to encode selected neoantigens to stimulate an immune response against cancer cells.

The therapy is being developed as part of Moderna's collaboration with Merck, which includes evaluation in combination with Keytruda.

Outstanding Data and Next Steps

The companies have not yet released full efficacy data from the Phase 3 trial, including detailed breakdowns of recurrence-free survival results. Overall survival data have not yet been reported.

The complete dataset is expected to be presented at a future medical meeting. Regulatory submissions will depend on the full data package. Pricing, manufacturing scale-up and commercial rollout plans have not been disclosed.

Moderna has previously said its oncology programme includes multiple ongoing studies of intismeran across different cancer types, with development timelines varying by indication.