Measles is the latest virus to be turned into a weapon against cancer

A false color image of the measles virus.

Arizona Department of Health

This week, clinical researchers at the Mayo Clinic announced some promising early results from a clinical trial that turned a killer into a therapy: their work harnessed a modified measles virus to attack a specific type of cancer. A larger clinical trial is still ongoing, but the people running this trial decided to describe two of the patients who received the virus, one of whom ended up in remission.

It's important to note that a short-term remission in one of the two patients who are described here doesn't come anywhere close to being a general cure for this type of cancer. Equally important is the fact that attempts to turn viruses into cancer killers go back decades, and a lot of the early trials also looked very promising. But to date, none of the viruses have been turned into treatments.

The idea behind using a virus to target cancer is the same one behind most other cancer treatments: cancer cells, although they look a lot like normal ones, have some key differences. Cancer cells express different proteins on their surface and control their growth differently. So it's possible to use these differences to design the right virus to specifically target cancer cells or only proliferate when infecting them. This may then lead to the death of the cancer cell, either by the virus itself killing it or because the virus attracts an aggressive immune response.