YS247 (Neoantigen-Pulsed DC Vaccine) for Metastatic Prostate Cancer

This phase I study tests a personalized cancer vaccine (Neo-DC) for men with advanced prostate cancer (metastatic castration-resistant prostate cancer, or mCRPC) that has continued to grow despite standard hormone therapies and other treatments. The vaccine is custom-made for each participant using their own immune cells (dendritic cells) mixed with specific tumor markers (neoantigens) unique to their cancer. These neoantigens are identified through genetic sequencing of the patient's tumor. The goal is to help the body's immune system recognize and attack the cancer cells specifically. The study will enroll approximately 9 to 18 men and will test three different dose levels to find the safest amount. Participants will receive the vaccine as an injection under the skin every two weeks for a total of 4 doses over an 8-week treatment period. The main purpose is to evaluate the safety of this vaccine, determine the maximum tolerated dose, and identify any serious side effects. Researchers will also look at whether the vaccine helps lower PSA levels (a blood marker for prostate cancer), slows cancer growth, and stimulates an immune response against the tumor. Participants will be monitored closely during treatment and followed for several months afterward to assess long-term safety and effects.