Moderna Shares Surge Over 200% as Personalized Cancer Vaccine Clears Key Trial

Moderna shares jumped over 200% in pre market trading, climbing to $174.51 after the company and Merck announced the first successful Phase 3 result for a personalized mRNA cancer vaccine. The stock had closed Tuesday at $62.96, and the surge occurred entirely in pre-market activity before regular trading began.

A New Approach to Fighting Cancer

The trial, known as INTerpath-001, tested a treatment built around each patient’s individual tumor. Doctors analyze the specific mutations present in a patient’s cancer, and Moderna then creates a custom mRNA shot targeting up to 34 unique tumor markers, training the immune system to recognize and attack them directly.

The study enrolled 1,137 patients with advanced melanoma following surgery. Those who received the personalized vaccine alongside Merck’s existing drug Keytruda remained cancer-free longer than patients treated with Keytruda alone, and also saw slower cancer spread to other organs. This marks the first time an mRNA-based cancer treatment has succeeded in a Phase 3 trial.

Why the Results Matter

Merck projects roughly 112,000 new melanoma cases and more than 8,500 deaths in the US this year alone. An earlier mid-stage trial of the same approach had already shown a significant reduction in recurrence risk. Moderna CEO Stéphane Bancel described the results as a major milestone, saying the long-standing goal of personalized cancer treatment is now becoming reality. The companies reported no new safety concerns compared to earlier studies.

Stock Still Recovering From Pandemic-Era Highs

Moderna’s shares had already more than doubled in value earlier this year, aided by a recent flu vaccine approval and a broadening product pipeline. Even with Wednesday’s gain, the stock remains far below its 2021 peak above $480, when COVID-19 vaccine demand drove its valuation sharply higher before falling more than 90%.