In 1904, a physician wrote about a patient with leukemia who went into remission when he got the flu. Though the patient was not cured, it was a ray of hope at a time when there were no treatments for leukemia. Other cases were reported throughout the years of people with Burkitt’s Lymphoma and Hodgkin’s Lymphoma going into remission when they had the measles. Since then, these observations stimulated experimental efforts to find a way of using viruses to cure cancer.
In the early days, with limited strategies to treat cancers, these experiments included harvesting infected tissues from sick individuals and giving these infections to patients with cancer. Cancer patients were infected with mumps, hepatitis, west nile virus among others, each experiment resulting in some patients having remissions or reductions in the size of their tumors. Unfortunately the remissions were short-lived and many of these experiments were less than scientific and ethically questionable.
Since 1974, studies have become more scientific and are guided by Institutional Review Boards or IRBs protect the welfare of research participants.
Genetically engineering and modifying virus genomes moved forward in the 1990’s and mid 2000’s. One such modification that scientists use to create oncolytic virus treatments involves removing the gene in the virus that is necessary for the virus to cause disease in normal, healthy cells. Another modification is to remove the gene that the virus uses to hide from the immune system.
These two modifications ensures that an oncolytic virus kills only cancer cells and that these viruses attract an immune response. Cancer cells also use special tricks to hide from the immune system but as the oncolytic virus kills cancer cells, it makes those cancer cells visible to the immune system. Then the immune system can identify cancer cells as other and attack uninfected cancer cells.
In this video, a head and neck tumor patient in Great Britain experiences remission using this treatment.