A Minnesota patient’s blood cancer has gone into complete remission after she was administered a strong dose of the measles vaccine as part of a clinical trial that confirms a “proof of concept” that some cancers can be eliminated with intravenous drugs.
Stacy Erholtz, a 50-year-old native of Pequot Lakes, was running out of treatment options for her blood cancer last year when she participated in a clinical trial at the Mayo Clinic, a nonprofit medical research group that has been conducting tests for 150 years.
Only one of two subjects in the experiment, Erholtz was injected with a measles vaccine strong enough to inoculate 10 million people. The disease, which had spread throughout her entire body, almost immediately became “undetectable” in front of Dr. Stephen Russell, the lead researcher on the project.
“It’s a landmark. We’ve known for a long time that we can give a virus intravenously and destroy metastatic cancer in mice,” Russell told the Star Tribune. “Nobody’s shown that you can do that in people before.”
Details of the research were first published Wednesday in the journal Mayo Clinic Proceedings.
Researchers have long known that viruses are capable of killing cancer in animals. The virus attaches itself to a cancerous tumor then uses it as a host to replicate its own genetic material. The overwhelmed cancer cells eventually buckle under the pressure and release the virus.
Doctors carry out this process either by injecting the virus directly into the tumor, thereby reducing the potential of error, or injecting the virus into the bloodstream and allowing it to find the tumor itself. The latter method was used on Erholtz, as much of her cancerous tumors were located in her bone marrow.
“Without trying to hype it too much, it is a very significant discovery,” Dr. John C. Bell of the Centre for Innovative Cancer Research in Ottawa told the Tribune, adding that the development represents a “benchmark to strive for and improve upon.”
Dr. Russell went on to explain that a single 11-year-old boy named David Edmonston has provided the strain that has been used to safely make all of the measles vaccines in the West. Though most people's immune systems attack the strain, patients with multiple myeloma – such as Erholtz – often have suppressed immune systems, which can allow the virus to spread and do its work.
Doctors were able to subvert Erholtz's immune system by extracting her cells, loading them with measles, and then injecting them back into her system.
“That way it doesn’t get destroyed before it reaches its target,” he said.
Ten-thousand infectious units of the measles virus are contained in a normal vaccine, yet patients in this case were given one million infectious units before the level was again increased to 100 billion infectious units.
However, the other patient tested in the study was not as lucky at Erholtz; that patient's immune system prevented doctors from administering another vaccine.
“I think that if we had been able to give a bigger dose, we might have got a better outcome in that second patient,” Russell told journalist Dan Browning.
The exciting revelation comes at a time when the Centers for Disease Control and Prevention is working to contain a growing measles outbreak in Ohio. The contagious disease has infected 68 people, adding to what was already the largest measles outbreak in 18 years in the US.
Vaccines normally prevent such situations, although several of the early cases were initially misdiagnosed, Dr. Julia Sammons wrote in an article published in the Annals of Internal Medicine.
“Because of the success of the measles vaccine, many clinicians have never seen measles and may not be able to recognize its features,” she wrote.