The purpose of the PerVision clinical trial is to evaluate the safety and effectiveness of a personalized peptide vaccine in treating pediatric and young adult patients with metastatic fusion-driven sarcoma. The vaccine is designed to target specific mutations and gene fusions found in each patient's tumor.

To be eligible for the study, patients must have metastatic fusion-driven rhabdomyo-, Ewing-, or synovial sarcoma and be in either their first or second complete remission or partial response. In addition, the tumor's sequencing data must be available. 

The vaccine is generated based on the individual patient's tumor mutations and specific gene fusion. The neopeptide with the highest binding prediction score and a second peptide derived from the sarcoma-specific fusion breakpoint are selected.

The study's primary objective is to evaluate the immunogenicity and safety/toxicity of the vaccine. Secondary objectives include comparing the immunogenicity of the predicted neopeptide with the sarcoma-specific fusion breakpoint peptide, evaluating event-free survival and overall survival, assessing the patients' quality of life during the trial, and correlating inducibility of immune responses with clinical patient characteristics.