Stocks
Moderna falls 17.6% after leaked melanoma vaccine data show a 42% cut in recurrence risk
Phase 3 results for the Moderna-Merck personalised cancer vaccine surfaced two days before their scheduled debut, and investors sold a stock that had more than tripled since August.
HedgeWeekly News Desk ·
Moderna shares closed down 17.6% at $202.63 on Thursday after detailed results from the late-stage trial of its personalised melanoma vaccine, developed with Merck, appeared online ahead of schedule. Reuters reported the stock down as much as 25.2% during the session, a drop it said erased about $24 billion of market value. Merck shares ended less than 2% lower.
The data were posted on the medical news site Oncology Central around 12:30 p.m. New York time and soon removed, according to reports. The European Society for Medical Oncology then lifted its embargo and released the abstract, and the two companies published the results. The full presentation remains on the ESMO Congress programme in Madrid on Saturday, October 24.
The INTerpath-001 trial enrolled 1,137 patients with high-risk melanoma whose tumours had been surgically removed. Adding the vaccine, intismeran autogene, to Merck's Keytruda cut the risk of recurrence or death by 42% versus Keytruda alone, with 82% of patients recurrence-free at two years against 70%. The risk of distant metastasis or death fell 38%. The companies said overall survival data were not yet mature but showed a favourable trend, and that they were in talks with regulators. Analysts at UBS and William Blair described the selloff as a sell-the-news reaction to solid data.
Why it matters: the reaction was about price, not efficacy. Before Thursday the stock had climbed to about $246 from its pre-August level, taking Moderna's value to nearly $90 billion, while its revenue fell from $6.85 billion in 2023 to $1.94 billion in 2025 as Covid sales faded. Citigroup cut the shares to sell on September 30, estimating Moderna would need about $13 billion a year of oncology revenue to justify the valuation. Investors will watch Saturday's full readout, the gap between the 38% metastasis benefit and the 59% seen in an earlier five-year mid-stage study, and progress in other tumour types, where intismeran is in nine Phase 2 and Phase 3 trials. Any melanoma sales would be split equally with Merck.