Moderna shares climbed more than 14% after positive Phase 3 trial results for intismeran autogene, the company’s personalized mRNA cancer vaccine.

Clinical data showed that intismeran, when combined with Merck’s Keytruda, extended recurrence-free survival in melanoma patients compared with Keytruda alone. The results marked the first successful late-stage trial for an mRNA-based cancer vaccine, and the first Phase 3 win for the broader field of personalized neoantigen vaccines, where rivals including BioNTech — working with Roche’s Genentech on a similar therapy, autogene cevumeran — are pursuing comparable approaches. The Phase 3 success builds on mid-stage results reported in late 2022, when the same combination reduced the risk of melanoma recurrence or death by 44% versus Keytruda alone, prompting the larger trial.

Shares of Moderna were trading near $154.94 during Tuesday’s session, up about 12% and making the stock the best performer in the S&P 500 for the day. The move followed a familiar pattern: Moderna’s stock initially surged after last week’s Phase 3 announcement, pulled back as investors took profits, and then resumed its advance.

The momentum centers on intismeran autogene (formerly code-named mRNA-4157/V940), Moderna’s customized mRNA-based cancer therapy developed with Merck under a collaboration that splits development costs and any future profits. The trial data indicated that the combination with Keytruda kept melanoma patients disease-free longer than treatment with Keytruda alone. For Moderna, the program carries outsized weight: the company’s revenue has fallen steeply from pandemic-era peaks as COVID-19 vaccine demand faded — Spikevax sales alone exceeded $18 billion in 2022 — and management has pointed to its oncology pipeline as its path back to growth.

The study enrolled 1,100 participants who received the investigational treatment after surgical removal of their melanoma tumors. Melanoma is the most serious form of skin cancer and accounts for the large majority of skin-cancer deaths; the American Cancer Society estimates roughly 100,000 new U.S. diagnoses each year. Intismeran is designed to target up to 34 neoantigens unique to each patient. These are abnormal proteins found on cancer cells that help the immune system identify and attack malignant tissue.

Each dose is tailored through genetic sequencing of a patient’s removed tumor to determine its specific mutational profile. The production process takes about six weeks from the initial cell sample collection to final vaccine delivery. During that period, patients can begin Keytruda treatment while waiting for their personalized therapy.

Wall Street Raises Targets and Upgrades Ratings

Barclays analyst Eliana Merle raised the firm’s price target on Moderna from $48 to $125 while keeping an Equal Weight rating. Merle said intismeran has favorable odds of successfully advancing through the regulatory approval process.

Wolfe Research upgraded Moderna from Underperform to Peer Perform on Tuesday. Analyst Alexandria Hammond said investor confusion over what qualifies as a cancer vaccine may have intensified last week’s sharp stock reaction.

BofA Securities and William Blair also upgraded Moderna after the trial results were released.

Wolfe’s models project unadjusted peak revenue of $9.2 billion across four indications: adjuvant melanoma, renal cell carcinoma (RCC), muscle-invasive bladder cancer (MIBC), and non-small cell lung cancer (NSCLC), before revenue sharing with Merck.

Leerink Partners expects intismeran to generate annual revenue in the low single-digit billions by 2032. Merck has projected about $6 billion in sales by 2035.

Questions Remain About Valuation

Last Wednesday, Moderna and Merck each added more than $40 billion to their market capitalizations in a single trading session. Against that backdrop, some analysts have warned that much of the potential upside may already be reflected in current valuations if peak sales reach the levels now being discussed.

Intismeran’s performance in other cancer types has not yet been proven. Nine additional trials are underway across solid tumors, including lung, kidney, and pancreatic cancers. Analysts generally view the melanoma data as encouraging for those studies, but further positive results are not guaranteed. Those readouts — along with the full melanoma dataset and the timing of any regulatory filings — are the next milestones markets are watching.

Current expectations point to 2027 as a realistic commercialization timeline, assuming interim data remains supportive. Moderna’s 52-week high is $176.66.

On Tuesday, Wolfe Research and Argus also raised their price targets on Merck, citing the company’s pipeline. Merck has been seeking a new major revenue source as it prepares for the eventual patent expiration of Keytruda, its top-selling drug and one of the world’s best-selling medicines, which generated $29.5 billion in sales in 2024 and begins losing key U.S. patent protection later this decade.