This study is testing a new vaccine called mRNA-0523-L001 to treat advanced endocrine tumors. Endocrine tumors affect glands that release hormones, like the thyroid or adrenal glands. Current treatments for these tumors often don’t work well, so this study is exploring a vaccine that uses neoantigens. Neoantigens are substances created by cancer cells that the immune system can target.

The main goal is to see if the vaccine is safe and if people can handle it well. They also want to see if it helps patients by activating certain immune cells called T-lymphocytes, which fight off the tumors, and to observe any tumor shrinkage or control.

• Participation requires being at least 18 years old with advanced endocrine tumors and no other treatment options.
• Participants must visit the clinic for tests and agree to use birth control during and after the study.
• The study excludes anyone who had recent surgeries, other cancer treatments, or certain health issues like severe heart disease.

If you're interested, you'll first need to sign a consent form and meet all the necessary criteria.