A 49 year old woman from Minnesota, diagnosed with myeloma years ago and having gone through chemotherapy and a pair of stem cell transplants, facing the prospect of no remaining options, enrolled in a two-patient, proof-of-principle clinical trial at the Mayo Clinic, where she received 100 billion units of a specially engineered measles virus.
This is enough to inoculate 10 million people.
Five minutes in, a vicious headache. Two hours in, severe vomiting and a temperature of 105 degrees.
Thirty-six hours in … her tumors had visibly shrunken. And several weeks in, she was cleared of the disease and in remission.
But before anyone gets too excited, remember that this was a two-person trial. The other person got the same injection but things didn't go the same way.
The patients received a single intravenous dose of a measles virus (MV-NIS) that had been engineered to be selectively toxic to myeloma plasma cells. It is an example of oncolytic virotherapy, therapy that uses a virus to infect and kill cancer cells while sparing normal tissue.
It is not a new field; this is not the first patient to be successfully treated with a virus; but it does serve as the first well-documented case of a patient with advanced cancer experiencing a complete remission following viral administration.
In an interesting side note, scientists engineered the virus to carry what they call a 'snitch gene'—an "easily identifiable marker" that allows it to be found wherever it is in the body using imaging studies.
Yes, there were two patients in this clinical trial, and the other patient did not have the same outcome. Their cancer didn’t respond as well.
This should serve as a reminder for people to remain very cautiously optimistic. This is going to require independent replication in larger studies to earn any credibility.
Nonetheless, Mayo researchers were clearly encouraged. "This is the first study to establish the feasibility of systemic oncolytic virotherapy for disseminated cancer," said Stephen Russell, MD, PhD, lead author of the study and a co-developer of the therapy. "These patients were not responsive to other therapies and had experienced several recurrences of their disease."
These findings were reported in the journal Mayo Clinic Proceedings.