Moderna shares fell more than 20% on Thursday after detailed results for its personalized melanoma vaccine, intismeran, developed with Merck, were apparently leaked online. A medical news website reportedly published the data and then removed it.
The results were scheduled to be presented on Saturday at the European Society for Medical Oncology congress. According to the inadvertently released report, intismeran combined with Merck’s Keytruda reduced the risk of cancer recurrence or death by 42%.
Investors appeared underwhelmed by the result compared with findings from an earlier, different study. Moderna and Merck shares both sold off.