There are several challenges to be overcome if therapeutic anticancer vaccines, which are designed to boost the patient's anticancer immune response, are to be successfully developed. For example, the viruses used to deliver the tumor protein to the patient's immune system are themselves targeted by the patient's immune system, inducing neutralizing and suppressive responses. But now, a team of researchers, led by Michael Morse, at Duke University Medical Center, Durham, has developed a way to overcome these neutralizing and suppressive responses by using an alphavirus packaged in virus-like replicon particles.

Repeated administration of such particles carrying the tumor protein CEA to patients with metastatic cancer expressing CEA induced clinically relevant immune responses targeted to CEA. As the presence of such immune responses was associated with longer overall patient survival, the authors hope their approach might be of therapeutic use in many cancer settings.