Stacy Erholtz had little chance of treating her metastasized blood cancer when she went to the Mayo last June to undergo an experimental treatment. Doctors then intravenously injected her with 100 billion infectious units of the measles virus, enough to inoculate 10 million people.
The "measles blitzkrieg" made Erholtz, a 50-year-old mother, a part of history. Doctors found that the cancer had been completely eradicated from her body, and she was in remission.
"It's a landmark," said Dr. Stephen Russell, a professor of molecular medicine and head researcher for the trial at Mayo. "We've known for a long time that we can give a virus intravenously and destroy metastatic cancer in mice. Nobody's shown that you can do that in people before."
Erholtz is one of two patients to receive such a radical treatment, and the only one to go into complete remission. The other patient did not go into full remission; unfortunately, for now, this treatment is a one-shot deal because the immune system would recognize the virus, should another attack occur.
This is not a new idea for researchers. They have known for decades that certain viruses can kill cancer. When a virus binds to a tumor, it uses the tumor as host to replicate its genetic material. The cancer cells then explode and release the virus into the body. With safe antiviral vaccines, the same process can instead carry radioactive molecules to destroy the cancer cells in the body while only dealing minimal damage to the healthy cells.
The research team also found that certain viruses will hone in and attack certain organs. Pneumonia and influenza will cause most harm to the lungs, and hepatitis damages the liver.
"We have a virus that can do that selectively to a tumor without at the same time causing damage to normal tissues in the body," Russell explained.
The treatment was created from the same measles strain taken from the throat of an 11-year-old boy in 1954, which led to the creation of the vaccine that would inoculate millions and almost entirely eradicate the disease from the U.S.
People who have been inoculated will find this treatment ineffective, but patients with myeloma have suppressed immune systems, allowing the vaccine to attack the cancer cells, inoculation or no.
There is still more research to do and the treatment still must go through randomized clinical trials. Until then, the doctors are reserved in their excitement.
"Unless we get to the third stage of development, we are only cautiously optimistic," said Dr. Tanios Bekaii-Saab, who is working on treating pancreatic cancer using Reolysin, a variant of the virus that causes the common cold.
The measles treatment research was published Wednesday in the journal Mayo Clinic Proceedings.