Level 1 — Absolute Beginner
Moderna and Merck are two big companies. They make medicine.
They have a new cancer vaccine. It works with another drug called Keytruda.
The vaccine helps people with skin cancer called melanoma. A big test shows it works well.
Moderna's stock price goes up a lot. Merck's stock price also goes up.
- vaccine
- a medicine that helps the body fight sickness
- cancer
- a serious sickness where bad cells grow in the body
- skin
- the outer part that covers the body
- drug
- a medicine used to treat sickness
- test
- a study to see if something works
- company
- a business that makes or sells things
- stock
- a small piece of a company that people can buy
- patient
- a person who gets medical care
Level 2 — Elementary
On Wednesday, Moderna and Merck shared good news about a new cancer vaccine. The vaccine is made just for each patient, so doctors call it 'personalized.'
Patients in the study used the vaccine together with a drug called Keytruda. All of the patients had melanoma, which is a serious type of skin cancer, and doctors had already removed it with surgery.
The study included 1,137 patients. The results showed that the vaccine plus Keytruda worked better than Keytruda alone, because the cancer came back less often and spread less often.
After the announcement, investors got excited. Moderna's stock price jumped by more than 100%, and Merck's stock price also went up.
- personalized
- made specially for one person
- melanoma
- a serious kind of skin cancer
- surgery
- an operation to remove or fix something in the body
- recurrence
- when a sickness comes back after treatment
- immunotherapy
- treatment that helps the body's immune system fight disease
- investor
- a person who buys stock hoping to make money
- combination
- two or more things used together
- announcement
- official news that is shared publicly
Level 3 — Intermediate
On Wednesday, August 19, 2026, Moderna and Merck announced that their personalized mRNA cancer vaccine, known as Intismeran (or mRNA-4157), had produced positive results when combined with Merck's immunotherapy drug Keytruda (pembrolizumab) in a large, late-stage clinical trial.
The trial, named INTerpath-001, enrolled 1,137 patients whose melanoma, a serious form of skin cancer, had already been completely removed through surgery, ranging in severity from stage IIB to stage IV.
The combination therapy met both its primary goal, reducing the recurrence of melanoma, and its secondary goal, reducing the cancer's spread to other parts of the body, when compared with patients who received Keytruda alone.
Because this is the first positive late-stage trial result for any mRNA cancer vaccine, analysts described it as a milestone for personalized cancer medicine, and investors reacted immediately: Moderna's shares soared as much as 106% in premarket trading, while Merck's shares climbed about 7%.
- clinical trial
- a scientific study that tests a treatment on real patients
- late-stage
- an advanced phase of testing, close to possible approval
- enrolled
- officially signed up to take part in a study
- resected
- surgically removed
- primary goal
- the main result a study is designed to measure
- secondary goal
- an additional result a study also measures
- milestone
- an important point marking progress or achievement
- premarket trading
- stock buying and selling that happens before the official market opens
Level 4 — Advanced
Moderna and Merck announced on Wednesday, August 19, 2026, that a large, late-stage clinical trial of their personalized mRNA cancer vaccine, Intismeran (mRNA-4157), administered alongside Merck's immunotherapy drug Keytruda (pembrolizumab), had returned unambiguously positive results, a development that industry observers immediately characterized as a watershed moment for the field of personalized oncology.
The trial, INTerpath-001, enrolled 1,137 patients whose melanoma, an aggressive form of skin cancer ranging from stage IIB through stage IV, had already been completely resected surgically, positioning the therapy as an adjuvant treatment intended to prevent the disease's return rather than to treat active tumors.
The combination regimen met both endpoints set out in the trial design: it significantly reduced the recurrence of melanoma, the study's primary objective, and it also reduced the cancer's spread to distant sites in the body, its secondary objective, when measured against Keytruda administered alone.
Because no mRNA cancer vaccine had previously delivered a positive result in late-stage testing, the announcement carried outsized weight, and financial markets responded accordingly: Moderna's shares soared as much as 106%, roughly doubling in premarket trading, while Merck's stock advanced by approximately 7%, reflecting investors' assessment that a durable, scientifically validated approach to personalized cancer treatment may now be within reach.
- oncology
- the branch of medicine dealing with the study and treatment of cancer
- adjuvant treatment
- additional therapy given after the main treatment (such as surgery) to lower the risk of the disease returning
- regimen
- a planned course of medical treatment
- endpoint
- a measurable outcome that a clinical trial is designed to assess
- durable
- lasting for a long time; not quickly fading
- watershed moment
- a turning point that marks a significant change
- distant sites
- parts of the body far from where a cancer originally started
- validated
- confirmed as accurate or effective through evidence