Moderna falls 17.57% to $202.63 despite positive melanoma vaccine results
Key Facts
Moderna shares closed down 17.57% at $202.63 on October 22, after falling more than 25% during the session, following the release of advanced results for its personalized melanoma vaccine. Phase 3 results showed that adding the vaccine to Keytruda reduced the risk of melanoma recurrence or death by 42% compared with Keytruda alone, according to Reuters. The full disclosure came after the data appeared earlier in the day on a specialist oncology website, ahead of their scheduled presentation. Reuters described the share move as a sell-the-news reaction after months of gains. The market response appeared at odds with the positive clinical indicators, as investors focused on the expectations for the program already reflected in the share price.
The trial included more than 1,100 patients and also showed that the combination treatment reduced the risk of cancer spreading by 38%, Reuters reported. After two years of treatment, 82.2% of patients who received the vaccine with Keytruda remained cancer-free, compared with 70% of those who received Keytruda alone. The comparison shows the two-year follow-up result alongside the indicators for the risk of recurrence or death and spread. The study enrolled patients with high-risk melanoma that had been surgically removed; participants then received Keytruda and were randomly assigned to receive either the personalized vaccine or a placebo, according to The Associated Press. The trial continues to track participants’ long-term outcomes.
The personalized vaccine is designed to match each patient’s tumor by identifying its genetic mutations and preparing a vaccine that trains the immune system to detect and attack new antigens, according to The Associated Press. The company said the process, from analyzing the tumor’s genes to preparing a vaccine prescription, can take about 6 weeks or longer, although manufacturing the dose itself takes a few days. The treatment is given as part of a post-surgery regimen, while the study tracks outcomes over a longer period. Researcher Hussein Tawbi said, "The field was looking for a win, and I think this is a major achievement." The results put the program among the company’s leading clinical bets, but come amid investment expectations that rose rapidly before the follow-up details were complete.
Moderna shares had more than doubled in August after the company announced preliminary trial results, according to The Associated Press. The two companies did not disclose details at the time on the duration of recurrence-free survival or improvement in overall survival, making the awaited full results a focal point for investors. Despite Thursday’s decline, the shares remained more than 200% above their level in late August, before the preliminary results were announced, the news agency reported. That came before the October 22 drop and does not establish that Citi’s recommendation caused that day’s move.
Merck shares also fell about 1.8% at the close on October 22, according to Reuters, despite the company’s role in developing the treatment with Moderna. The melanoma results were scheduled to be presented at the European Society for Medical Oncology meeting in Madrid on Saturday, October 24, after Merck said on October 13 that Phase 3 data would be presented in a presidential session at the 2026 conference. The leak accelerated the companies’ release of the results ahead of the scheduled presentation. The companies said they are preparing to file for U.S. approval, while Moderna’s chief executive expects the vaccine to launch in 2027. The Associated Press reported that the companies are discussing next steps for an approval application with regulators, while long-term follow-up of participants continues.