On August 19, pharmaceutical giant Merck and biotechnology firm Moderna announced that their personalized mRNA vaccine for melanoma has successfully met its primary and one of its key secondary endpoints in the third phase of clinical trials.

The experimental treatment involved the use of intismeran autogene (also known as V940 or mRNA-4157) in conjunction with Merck's anti-cancer drug Keytruda.

Trial Results

The INTerpath-001 study included 1,137 patients with stages IIB-IV melanoma who had undergone complete tumor removal. Participants were divided into two groups: one received the intismeran autogene alongside Keytruda, while the other was treated with Keytruda alone.

The combination treatment demonstrated a statistically significant improvement in two metrics: recurrence-free survival and distant metastasis-free survival.

This marks the first positive outcome in phase three for personalized neoantigen therapy and mRNA cancer treatments.

However, specific efficacy metrics have not yet been disclosed, with plans to present the findings at an international medical conference.

The study will continue, with researchers assessing overall survival and other parameters. No new safety risks have been identified compared to earlier trials.

In the second phase, the combination also outperformed Keytruda alone. After five years of observation, the risk of recurrence or death was reduced by 49%, while the risk of distant metastasis or death decreased by 59%.

AI's Role in Vaccine Development

Unlike traditional vaccines, intismeran autogene is tailored for each individual patient.

Initially, specialists sequence tumor and blood samples. Then, Moderna's algorithms analyze the identified mutations and select up to 34 neoantigens, which are potential targets for the immune system.

Based on these findings, the company manufactures a personalized mRNA vaccine. Once administered, it is designed to train the immune system to recognize tumor-specific targets and attack cancer cells.

Moderna employs various integrated AI tools in this process. These tools assess genetic data and predict which neoantigens are most likely to elicit an immune response.

The company also utilizes artificial intelligence in its production logistics. Each vaccine is unique, prompting Moderna to use algorithms for optimizing manufacturing capacity and scheduling the release of thousands of individual batches.

In contrast, Keytruda works by blocking the mechanism through which tumor cells suppress the immune response. Together, one therapy helps the immune system identify the target while the other enhances its attack.

Moderna's Stock Skyrockets by 130%

Following the announcement of the trial results, Moderna's stock surged by approximately 131%, reaching $163, marking the largest single-day increase in the company's history.

As of the time of writing, the stock price has adjusted downwards by nearly 15%.

Source: Yahoo Finance.

This sharp rise has impacted traders who had bet against Moderna, as reported by Reuters, citing analytics platform ORTEX. Unrealized losses for market participants reached approximately $4.8 billion. Prior to this event, around 13.5% of the company's shares in circulation were sold short.

Merck and Moderna plan to present the results to regulators and discuss filing for approval of the intismeran autogene and Keytruda combination. The therapy remains experimental and has not yet received approval for use.

The companies are also exploring the use of intismeran autogene for other cancer types, including lung, bladder, and kidney tumors.

In October 2025, a Google AI model predicted a drug combination that could make "cold" tumors detectable to the immune system, a hypothesis confirmed in laboratory experiments.

Previously, a neural network from Redmod learned to identify pancreatic cancer in CT scans on average 475 days prior to diagnosis.