after signing the consent form, you are assigned to one of the study groups by a computer system.

the groups may include pembrolizumab plus mrna-4157, pembrolizumab alone, or placebo.

a series of tests are performed to record your health status before treatment begins.

these tests may include blood work, imaging scans, and questionnaires about quality of life.

if you are assigned to the pembrolizumab group, a single injection of 790 mg of pembrolizumab is given under the skin (subcutaneous use).

if you are also assigned to receive mrna-4157, a single injection of 1 mg is given into the muscle (intramuscular).

if you are assigned to the placebo group, a matching injection that does not contain active drug is given.

additional injections of the same type and dose are given at intervals defined by the study protocol.

each injection follows the same route: subcutaneous for pembrolizumab and intramuscular for mrna-4157.

you attend scheduled visits to the clinic where health professionals check for side effects and overall well‑being.

blood samples and imaging scans may be performed to monitor disease status.

periodic scans are done to assess disease‑free survival, which means checking whether the cancer has returned.

the assessments are reviewed by an independent central review team.

any new symptoms or changes in health are recorded and reported to the study team during visits or by phone.

the study records the number of participants who experience adverse events and those who stop treatment because of them.

if severe side effects occur, the study protocol may require stopping the injections.

the decision is made according to predefined safety criteria.

at the end of the study period, a comprehensive evaluation is performed, including final imaging, blood tests, and quality‑of‑life questionnaires.

the results contribute to the overall analysis of the trial.