As part of a two-person clinical trial to treat cancer, doctors at the Mayo Clinic injected two women with an exorbitant amount of the measles virus, resulting in one of the patients going into remission.
“Thirty-six hours after the virus infusion was finished, [myeloma patient Stacy Erholtz] told me, ‘[The tumor] has started shrinking,’” lead researcher Stephen Russell tells the Washington Post.
Fifty-year-old Erholtz of Minnesota suffered from a rare blood cancer that affects bone marrow. She had already undergone chemotherapy and two stem cell transplants before becoming a candidate for the clinical trial.
Russell and his research team had engineered the measles virus to make it more suitable for cancer treatment. For those of us who wonder how in the world this works, the Star Tribune explains:
[Viruses] bind to tumors and use them as hosts to replicate their own genetic material; the cancer cells eventually explode and release the virus. Antiviral vaccines that have been rendered safe can produce the same effects and can also be modified to carry radioactive molecules to help destroy cancer cells without causing widespread damage to healthy cells around the tumors. The body’s immune system then attacks any remaining cancer that carries remnants of the vaccine’s genetic imprint.
Russell tells the Washington Post the process took an hour. Five minutes in, Erholtz got a terrible headache. By the second hour, she was shaking and vomiting as her temperature hit 105 degrees. But over the following several weeks, Erholtz’ tumor on her forehead completely disappeared and eventually the other tumors in her body did, too.
The treatment was successful in Erholtz, whose cancer was in her bone marrow; however, the trial failed on the second patient, whose tumors were mainly in her leg muscles.
Russell says the trial taught them two things.
“Number one, you need a really big dose.” Russell’s team injected Erholtz with 100 billion units of the measles virus – enough to inoculate 10 million people. “And number two, the patient needs to not have an antibody to the virus.”
The next step is another clinical trial, which is expected to launch by September, to see if the massive measles dosage works on a large number of patients.
“What this all tells us is something we never knew before – we never knew you could do this in people,” Russell says. “It’s a very important landmark because now we know it can happen. It’s a game changer. And I think it will drive a development in the field.”