TradingKey - On October 22, Eastern Time, shares of Moderna (MRNA) plummeted as much as 25% intraday. As of press time, the stock was still down 24.24% at $186.23.
It is reported that the company and Merck (MRK) are set to release full Phase 3 data for their jointly developed melanoma vaccine. Meanwhile, rumors are circulating in the market that trial results were leaked prematurely, though this has not been officially confirmed.

Moderna stock chart, Source: TradingView
According to company announcements, the two sides will present the results of the INTerpath-001 study at the European Society for Medical Oncology (ESMO) Congress in Madrid on October 24. The study compares the efficacy of the individualized mRNA therapy intismeran autogene combined with Keytruda against Keytruda alone in treating patients with resected Stage IIB to IV melanoma.
This investigational vaccine targets patients who still face the risk of recurrence after surgery, aiming to improve treatment outcomes through individualized immunotherapy.
For investors, the full data will help evaluate its clinical value and future sales potential. Judging from the sharp volatility ahead of the release, the market may be reassessing the optimistic expectations previously priced into the stock. Meanwhile, leak rumors have added to this uncertainty.