Moderna falls after positive melanoma vaccine results emerge

Moderna shares plunged on October 22 after late-stage results for its personalized melanoma vaccine, developed with Merck, became public, even as the companies reported reduced risks of recurrence and cancer spread. Merck shares also fell, but by less. The results had circulated online ahead of a scheduled conference presentation, and the market reaction followed a long rally in Moderna stock. The companies said that adding intismeran autogene to Merck’s Keytruda reduced the risk of melanoma recurrence or death by 42% compared with Keytruda alone. They also reported a 38% reduction in the risk of distant metastasis or death. The findings came from a late-stage trial involving more than 1,100 patients with high-risk melanoma. Moderna fell as much as 25% during the October 22 session, then recovered some losses. One report said trading was briefly halted because of volatility. Merck shares declined by about 1% to 1.4%, depending on the time of observation. On October 23, Moderna was down 4% at $193.62 in morning trading, extending the previous session’s drop. The company’s market value fell by about $24 billion on October 22, according to one report. The European Society for...