Merck and Moderna have announced groundbreaking positive Phase 3 results for an investigational cancer treatment that combines an individualized mRNA therapy with Merck’s established immunotherapy, KEYTRUDA. This marks a pivotal clinical milestone for personalized cancer treatment, particularly for patients with high-risk melanoma.
Trial Success in Melanoma
The INTerpath-001 trial successfully met both its primary endpoint of recurrence-free survival (RFS) and a key secondary endpoint of distant metastasis-free survival (DMFS). These results were observed in patients with completely resected stage IIB-IV melanoma, demonstrating a statistically significant and clinically meaningful improvement compared to KEYTRUDA alone.
Professor Georgina Long, principal investigator for the study and Medical Director of Melanoma Institute Australia, highlighted the significance: “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 in patients with completely resected stage IIB-IV melanoma compared to KEYTRUDA alone.”
How the Personalized Vaccine Works
The investigational treatment, known as intismeran autogene (also V940 or mRNA-4157), is a personalized neoantigen therapy. It works by analyzing a sample of an individual patient's tumor to identify its unique genetic mutations. A synthetic mRNA therapy is then created, encoding up to 34 neoantigens – specific markers on the cancer cells.
The aim of this innovative approach is to train the patient's immune system to recognize and effectively attack cancer cells carrying these tumor-specific markers, thereby preventing recurrence and metastasis.
Trial Design and Participants
The global Phase 3 trial enrolled 1,137 patients diagnosed with high-risk, resected cutaneous melanoma. Patients were randomized in a 2:1 ratio to receive either the combination of intismeran plus KEYTRUDA or KEYTRUDA alone. The treatment regimen involved intismeran administration every three weeks for up to nine doses, alongside KEYTRUDA every six weeks for approximately one year, following complete surgical removal of the melanoma.
Future Implications and Next Steps
For Merck, these positive findings expand the potential applications for KEYTRUDA, which is already a cornerstone in melanoma treatment. The company is actively pursuing a strategy to test cancer medicines earlier in the disease course, with over 30 ongoing studies across various cancer types.
Moderna views this trial as a crucial validation of its mRNA technology's potential beyond infectious diseases and into oncology. Stéphane Bancel, CEO of Moderna, expressed enthusiasm: “These Phase 3 findings represent a pivotal moment for the field of cancer research... We are now helping turn that vision into a reality.”
The companies are jointly developing intismeran across a broader clinical program, including nine Phase 2 and Phase 3 studies for melanoma, non-small-cell lung cancer, bladder cancer, renal cell carcinoma, pancreatic, gastric, and other lung cancers.
Dr. Dean Y. Li, president of Merck Research Laboratories, emphasized the goal: “By intervening earlier in the course of disease, when many cancers are considered most treatable, the goal of adjuvant therapy given after surgery is to increase the possibility of cure for more patients.”
The safety profile of the combination treatment in INTerpath-001 was consistent with prior studies, with no new safety signals reported. Merck and Moderna plan to present detailed data at an upcoming international medical meeting and will engage with regulatory authorities regarding potential filing submissions for intismeran in combination with KEYTRUDA.
The trial will continue to assess other endpoints, including overall survival, as part of its ongoing evaluation.