Moderna and Merck released early results from a phase 3 trial of a personalized mRNA cancer vaccine after the data leaked on social media on Thursday, and the companies said the combined treatment reduced the chances that patients with high-risk melanoma would see their tumors return.1,3
The trial included 1,137 patients with high-risk melanoma, a type of skin cancer, and tested two treatments. The first, intismeran autogene, is a personalized mRNA vaccine that works by instructing the body in how to identify and fight cancer. The second, pembrolizumab, sold as Keytruda, is a drug designed to prevent cancer from hiding from the immune system, according to Merck.3
Compared with patients who received pembrolizumab alone, those who received the combination had a 42 percent lower risk of cancer recurrence or death after a median period of about two years, Moderna and Merck said. The companies also said the combination reduced the risk of the cancer spreading to other parts of the body or death by 38 percent compared with pembrolizumab alone.3
The leak also affected Moderna's stock. Moderna's shares plunged after the data leaked, even though the results were positive. How far the shares fell was not stated in the material available for this story.2,3
Karen Knudsen, chief executive of the Parker Institute for Cancer Immunotherapy, a nonprofit, called the results "really encouraging." She said a vaccine of this kind was "fiction" 10 years ago. "It was thought to be very difficult to do," she said.3
The findings do not yet include overall survival. Knudsen said, "Did people who got the vaccine live longer than people who didn't? And what was their quality of life?" She said those results are coming, and described the new findings as "really, really good milestones along the way."3
In a statement, Moderna CEO Stéphane Bancel said, "From the beginning, we believed mRNA technology could make it possible to develop cancer treatments uniquely matched to each patient's tumor." He added, "These results reinforce our conviction that mRNA has the potential to fundamentally change how we treat cancer."3
Moderna and Merck did not immediately respond to requests for comment from Scientific American. It was not known from the material available for this story whether the companies had addressed the drop in Moderna's shares.3
The results have been accepted for publication in the New England Journal of Medicine, Merck and Moderna said. The companies are "engaging with regulatory authorities" to seek approval for the mRNA vaccine.3
