Moderna stock plummets after reported leak of disappointing cancer-vaccine data

Stock in the pharmaceutical and biotechnology company Moderna plummeted Thursday after details from its closely guarded mRNA-based cancer-vaccine study were reportedly shared early.

The shares dropped by nearly 18% at the close of the day, according to the Wall Street Journal, as apparently positive results still fell short of expectations.

The company had claimed in August that its vaccine, when taken with Merck's cancer therapy Keytruda, had prevented melanoma, which is a serious form of skin cancer, from returning or spreading. 

The study found that the vaccine reduced the risk of the cancer spreading by 38% in patients with high-risk melanoma when compared against a standard immunotherapy treatment, the Wall Street Journal reported, and the vaccine reduced the risk of a recurrence or death from melanoma by 42%. 

The drop comes after the study's results were scheduled to be released on Saturday at the European Society for Medical Oncology conference, but were leaked by the cancer-focused website OncologyCentral early. The article containing the leak has since been deleted.

Shares of Merck dropped 1.7% on Thursday.

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.