默沙东与Moderna个性化mRNA黑色素瘤疫苗III期初步数据达标，但股价已在当日大幅重定价

An experimental personalized cancer vaccine from Merck and Moderna showed positive initial results in its first-ever late-stage trial, the companies announced Wednesday, bringing them one step closer to filing for approval of the treatment option.
The mRNA-based shot in combination with Merck's immunotherapy Keytruda met key goals in the Phase 3 trial in more than 1,100 patients with higher-risk or advanced melanoma whose detectable cancer had been completely removed through surgery.
Merck shares climbed more than 12% on Wednesday, while Moderna's stock soared about 177%. The size of those moves reflect the companies' relative size entering Wednesday: Merck's market cap was around $333 billion, while Moderna's sat near $25 billion.
The combination regimen met the main study goal of significantly extending the time patients lived without their melanoma returning, compared with Keytruda alone. The treatment also reduced the risk of the cancer spreading to distant parts of the body. Those results build on positive Phase 2 trial data on the same regimen earlier this year.
"It's a big moment for medicine, a big moment for patients," Moderna CEO Stephane Bancel said in an interview on CNBC's "Squawk Box."
The Phase 3 study will continue to assess other outcomes, including the overall survival benefit of the regimen. The drugmakers plan to present the data at an upcoming international medical meeting, but it's unclear when they plan to submit applications for approval in the U.S.
The drugmakers will likely start talking to regulatory agencies about the treatment and its safety "in the next few months," Dr. Dean Li, president of Merck Research Laboratories, told "Squawk Box."
The initial data suggests that the combo could serve as a new treatment option for melanoma, which accounts for only about 1% of skin cancers but causes the large majority of deaths among them. Most recurrences of melanoma develop in the first two to three years after initial treatment and removal.
Melanoma patients are "stuck having to deal with the new gravity of that diagnosis and then undergo uncomfortable treatments like surgery, and after that, they're worried about their cancer coming back," Dr. Jane Healy, Merck's head of oncology early development, said in an interview.
She called it "very exciting" that the therapy led to a "clinically meaningful improvement" over Keytruda – the standard of care for melanoma – and was well tolerated by patients. Side effects were similar to other vaccines that people typically get for other diseases, Healy noted.
The results also validate a personalized treatment approach that Merck and Moderna have been developing for decades, she added.
Every tumor has a unique set of mutations, even among patients with the same type of cancer, Healy said. Merck and Moderna's personalized vaccine is designed to target the specific mutations in each patient's tumor rather than using a one-size-fits-all approach. The idea is to train the immune system to recognize and kill those unique cancer markers and then pair that response with Keytruda, which helps the body attack the cancer more effectively.
"We think [the results are] very meaningful for patients with this disease and really the potential of what it can mean for other patients for cancer in future trials with this particular new class of therapy," she said.
In a June note ahead of the results, Leerink Partners analyst Mani Foroohar said the Phase 3 results are a make-or-break event for Moderna's stock.
Analysts said the company's valuation already reflected expectations that the personalized cancer vaccine could eventually work across multiple types of cancers – not just melanoma — before Wednesday's stock move.
Merck and Moderna are studying the vaccine in several trials across other tumors, such as non-small cell lung cancer, bladder cancer and renal cell carcinoma.