Moderna Inc (NASDAQ:MRNA, XETRA:0QF) and Merck & Co Inc (NYSE:MRK, XETRA:6MK) said Wednesday their personalized mRNA cancer vaccine, intismeran, combined with Merck's Keytruda slowed melanoma recurrence and spread in a Phase 3 trial, in what would be the first randomized late-stage validation of a personalized neoantigen cancer vaccine.
Moderna shares jumped 150% Wednesday morning, while Merck rose 10.3%.
The trial, known as INTerpath-001, tested the combination in 1,137 patients with Stage IIB-IV melanoma following surgery. An independent panel found the treatment met the study's first prespecified interim analysis, beating Keytruda alone on recurrence-free survival, the primary endpoint, as well as distant metastasis-free survival, a key secondary endpoint. The study was stopped early after the positive results.
Detailed efficacy data have not yet been released and are expected to be presented at a medical meeting, according to Jefferies. The trial will continue to gather data on secondary endpoints including overall survival.
Analysts at Jefferies said the result could carry over to Moderna's more than eight other Phase 2 and 3 programs testing the vaccine, known as INT, in solid tumors including renal cell carcinoma, bladder cancer, non-small cell lung cancer and metastatic melanoma, with some near-term readouts expected in late 2026 and 2027.
Moderna and Merck have a 50/50 profit-sharing collaboration on the vaccine. Jefferies said Moderna plans to recognize revenue from its share of profits and reimbursement of costs paid by Merck, meaning reported revenue would not reflect full end-market sales.
The vaccine could enter the melanoma market in 2027, with pricing potentially competitive with Keytruda, which costs about $200,000, according to Jefferies.
Moderna has described its pipeline as spanning three horizons: late-stage and commercial products, early-stage programs, and AI/ML-enabled drug discovery. Jefferies said the company could be marketing more than seven products by 2027-28 across respiratory, oncology and rare-disease categories, with 2026 revenue potentially growing as much as 10% from $1.9 billion in 2025.