Moderna's shares experienced an extraordinary surge of 177% in overnight US trading, hitting a high of $174.38 apiece on the NYSE. This dramatic market reaction followed the announcement that the biotechnology company, in collaboration with Merck, had achieved primary endpoints in their Phase 3 personalized cancer vaccine trial for melanoma.
The experimental personalized cancer vaccine, known as intismeran autogene (mRNA-4157), is being studied for its efficacy in treating melanoma. This form of skin cancer, while accounting for only about 1% of all skin cancers, is responsible for the majority of deaths from the disease. Merck's shares also saw a significant climb, rising 12.60% to $152.20.
Landmark Results in Melanoma Treatment
The Phase 3 trial, INTerpath-001, specifically evaluated the combination of intismeran autogene with Merck's established cancer therapy, KEYTRUDA (pembrolizumab). At a pre-specified interim analysis, the combined therapy demonstrated statistically significant and clinically meaningful improvements in recurrence-free survival and distant metastasis-free survival compared to KEYTRUDA alone. This marks a pivotal moment, as it is the first and only regimen in the adjuvant melanoma setting to achieve such results.
Professor Georgina Long, the study’s principal investigator and medical director of Melanoma Institute Australia, hailed the findings as a "landmark moment for adjuvant melanoma treatment." She emphasized that intismeran, designed based on a patient's unique tumor 'fingerprint,' combined with pembrolizumab, significantly reduces the risk of recurrence or death for patients with completely resected stage IIB-IV melanoma.
Dr. Dean Y. Li, president of Merck Research Laboratories, underscored the potential of personalized approaches in cancer treatment, stating that intervening earlier in the disease course, when many cancers are most treatable, increases the possibility of cure. Stéphane Bancel, CEO of Moderna, echoed this sentiment, calling the findings a "pivotal moment for the field of cancer research" and a realization of the long-held aspiration to create individualized mRNA treatments for cancer.
Trial Details and Future Plans
The global Phase 3 INTerpath-001 trial enrolled 1,137 patients with high-risk, resected cutaneous melanoma. Patients, after complete surgical resection, were randomized to receive either intismeran and KEYTRUDA or KEYTRUDA alone. The primary endpoint was recurrence-free survival, with key secondary endpoints including distant metastasis-free survival, overall survival, safety, tolerability, and quality of life.
The companies reported that the safety profiles observed in the trial for the combination of intismeran and KEYTRUDA were consistent with previous studies, with no new safety signals identified. Building on earlier Phase 2b results, which showed a 49% reduction in the risk of recurrence or death, and a 59% reduction in the risk of distant metastasis or death, these Phase 3 findings solidify the therapy's promise.
Merck and Moderna plan to present the comprehensive data from the trial at an upcoming international medical meeting. Following this, they will engage with US regulatory authorities to initiate submissions for intismeran autogene in combination with KEYTRUDA. The broader INTerpath clinical development program continues, exploring the therapy's safety and efficacy across multiple tumor types and disease stages, including non-small cell lung cancer, bladder cancer, and renal cell carcinoma.
How the Personalized Vaccine Works
Intismeran autogene is an investigational mRNA-based individualized neoantigen therapy. It is uniquely designed and produced using a patient's specific tumor sample. This sample allows for the identification of the cancer's unique mutational signature, or "fingerprint," which is then used to generate an anti-tumor immune response. Each therapy consists of synthetic mRNA coding for up to 34 neoantigens, precisely tailored to the individual patient's tumor biology.
Once administered, the RNA-encoded neoantigen sequences are translated within the body and presented to the immune system. This process is intended to generate specific T-cell responses that target and fight the cancer cells. This personalized approach aims to harness the body's own immune system to combat one of the deadliest forms of skin cancer.