Oncolytic Virus - History

History

A connection between cancer and viruses has long been theorized, and case reports of cancer regression (cervical cancer, Burkitt lymphoma, Hodgkin lymphoma) after immunization or infection with an unrelated virus appeared at the beginning of the 20th century. Efforts to treat cancer through immunization or deliberate infection with a virus began in the mid-20th century. As the technology for creating a custom virus did not exist, all early efforts focused on finding natural oncolytic viruses. During the 1960s, promising research involved in using poliovirus, adenovirus, Coxsackie virus, and others. The early complications were occasional cases of uncontrolled infection, resulting in significant morbidity and mortality; the very frequent development of an immune response, while harmless to the patient, destroyed the virus and thus prevented it from destroying the cancer. Only certain cancers could be treated through virotherapy was also recognized very early. Even when a response was seen, these responses were neither complete nor durable. The field of virotherapy was nearly abandoned for a time.

With the later development of advanced genetic engineering techniques, researchers gained the ability to deliberately modify existing viruses, or to create new ones. All modern research on oncolytic viruses involves viruses that have been modified to be less susceptible to immune suppression, to more specifically target particular classes of cancer cells, or to express desired cancer-suppressing genes.