Why Moderna Fell on Encouraging Trial News

Moderna Inc stock plunged nearly 24.0% in mid-day trading after what appeared to be an early, unauthorized publication of embargoed Phase 3 trial results for its personalized mRNA cancer vaccine sent shockwaves through the market. The data, covering the INTerpath-001 trial of Intismeran autogene combined with Merck's Keytruda immunotherapy in melanoma patients, appeared on medical news website Oncology Central around 12:30 p.m. ET before being taken down shortly afterward - well ahead of its planned debut at the European Society for Medical Oncology congress in Madrid on Saturday. The breach triggered a volatility-related trading halt in MRNA shares mid-session. rattled The leaked figures themselves were clinically encouraging: the combination reduced the risk of melanoma recurrence or death by 42% compared with Keytruda alone, and 82.2% of patients in the combination arm remained allve and cancer-free after two years versus 70% on Keytruda alone across the 1,137-patient study. Yet the manner of disclosure an apparent embargo violation rather than a controlled presentation investors who had bid the stock to a 52-week high of $254.48 just the prior session. Adding to the pressure, Citi analyst Geoff Meacham maintained a Sell rating on the stock with an $80 price target, underscoring persistent valuation concerns even as TD Cowen raised its price target to $90 from $40 while keeping a Hold rating. The broader market environment offered no cushion for the battered biotech. The NASDAQ fell -2.4% on the day, while the S&P 500 declined -1.3%, reflecting broad pressure on growth and technology-orlented names. Moderna's selloff, however, dwarfed those index moves by a wide margin, confirming the data leak as the dominant stock-specific driver rather than any macro event.