Moderna closes at $202.63 after falling more than 17% despite melanoma vaccine cutting recurrence by 42%
Key Facts
Moderna and Merck said Moderna’s personalized vaccine intismeran autogene, when added to Keytruda, reduced the risk of melanoma recurrence or death by 42% over the first two years, compared with Keytruda alone, in a Phase 3 trial. Moderna shares closed at $202.63 on Oct. 22, down more than 17%, while Merck shares fell about 1.8%, according to Reuters. Moderna’s decline followed a leak of the results on an oncology-focused website earlier in the day, ahead of their scheduled presentation at the European Society for Medical Oncology conference. Reuters reported that the drop erased about $24 billion from the company’s market value. Still, the stock remained more than 200% above its late-August level, before the initial announcement that the trial had succeeded, according to the Associated Press.
The INTerpath-001 trial included more than 1,100 patients with surgically removed high-risk melanoma, according to the Associated Press. Participants received Keytruda and were then randomly assigned to receive the personalized vaccine or a placebo. After two years, 82.2% of those who received the vaccine with Keytruda were cancer-free, compared with 70% in the Keytruda-only group, according to Reuters. These percentages measure participants’ status at the two-year mark, while the relative risk reduction compares the likelihood of disease recurrence or death between the two treatment groups. The results also showed a 38% reduction in the risk of distant metastasis or related death, compared with Keytruda alone. The trial continues to track participants to assess longer-term outcomes, according to the Associated Press.
The vaccine targets neoantigens associated with mutations in each patient’s tumor and is given in a regimen of 9 doses spaced 3 weeks apart, according to the Associated Press. The treatment is personalized because its design starts with an analysis of the tumor’s genes to identify antigens the immune system may recognize. Moderna Chairman Stephen Hoge said manufacturing the dose itself takes a few days, but the process from tumor analysis to determining the vaccine formula can take about 6 weeks or more. That timeline makes preparing the treatment for each patient central to how it is delivered, alongside the defined dosing regimen. “The field has been looking for a win, and I think this is a big win,” researcher Hussein Tawbi told the Associated Press.
The stock’s decline followed a rally after the initial announcement of the trial’s success in August; the Associated Press reported that shares remained more than 200% above their level in late that month. Reuters quoted analysts as saying investors had been looking for a reduction in recurrence risk of 40% or more. The 42% reduction exceeded that level, while a Reuters report said one analyst described the stock move as a sell-the-news reaction after the rally. Reuters reported that the Oct. 22 decline erased about $24 billion from Moderna’s market value, despite the stock having risen more than 500% during the year through that date. Positive trial data thus coincided with a contrary market move after details leaked, at a time when expectations were already high.
Moderna and Merck said they are engaging with regulators on next steps for an approval application and are preparing to submit a U.S. approval application. Moderna’s chief executive expects the vaccine to launch in 2027, according to Reuters. Merck said INTerpath-001 results will be presented in a presidential session at the 2026 European Society for Medical Oncology conference, which runs in Madrid from Oct. 23 to 27. Reuters had reported that overall survival data were not yet mature, but showed a trend it described as “positive.” The trial continues to follow participants to assess longer-term outcomes, according to the Associated Press.