Moderna shares nearly tripled after Moderna and Merck reported positive Phase 3 results for intismeran autogene, also known as mRNA-4157, a personalized mRNA vaccine used with Merck’s Keytruda to treat patients with resected melanoma. The treatment met its primary goal of preventing melanoma recurrence and a secondary goal of preventing the cancer from spreading elsewhere, making it the first successful Phase 3 readout for a customized mRNA cancer treatment. The move added about $44 billion to Moderna’s market value and marked its strongest day as a public company, after shares had fallen more than 90% from their pandemic peak. Earlier results showed the combination reduced the risk of melanoma recurrence or death by 44% versus Keytruda alone, while the companies have not disclosed the latest treatment’s effectiveness, patient response rate, durability or production cost. Moderna and Merck plan to present detailed data at a medical conference later this year and are targeting potential U.S. approval next year, although regulatory and manufacturing hurdles remain. The program is central to Moderna’s effort to diversify after COVID-19 revenue fell from $19.3 billion in 2022 to $1.9 billion in 2025.