A layman's question: is it implied to be a universal cure, or for a specific type?
Both. It's targeted by injecting into one tumour, but many different tumours can be targetted. Once targetted, this tumour is eliminated along with all "copies" in body. If you had breast cancer and colon cancer you would need two injections.
It's also not clear what toxicities were incurred with this therapy (in mice), which is a significant concern for the approval of any drug in humans.