Mayo Clinic scientists have converted the measles virus into a cancer-fighting agent that targets myeloma plasma cells. In a proof of principle clinical trial, one patient with multiple myeloma took a single dose of the engineered measles virus (MV-NIS) and had all signs and symptoms of her cancer disappear. The patient has now been cancer-free for six months.
"Ask an oncologist about the developing cancer treatments using virotherapy."
Stephen Russell, MD, a hematologist (doctor who treats blood disorders) with the Mayo Clinic in Rochester, Minnesota, co-developed this cancer-killing virus and served as first author of the study.
Virotherapy is an emerging form of cancer therapy that uses oncolytic viruses, which infect and kill cancer cells but do not harm healthy tissues.
In this trial conducted last year, two patients with multiple myeloma received the highest possible amount of vaccine in one hour-long intravenous dose — enough to inoculate 10 million people. The patients had not responded adequately to other therapies. Cancer had spread through their bodies and they had run out of treatment options.
One of the participants, a 49-year-old woman with late-stage cancer, had received chemotherapy and stem cell transplants, but these treatments were ineffective. Shortly after taking the MV-NIS, her temperature spiked at 105 degrees, and she was shaking and vomiting. Within two days, her tumors began to shrink. The woman was found to be in complete remission after six months.
Both participants experienced a decrease in bone marrow cancer and the myeloma protein. A high level of this protein in the blood is a major characteristic of myeloma.
The second patient, however, did not respond as well to the virotherapy, but imaging revealed that the vaccine was specifically targeting tumor sites.
“This is the first study to establish the feasibility of systemic oncolytic virotherapy for disseminated cancer,” said Dr. Russell is a statement. “These patients were not responsive to other therapies and had experienced several recurrences of their disease.”
The authors also noted that these two patients had fewer antibodies to fight the virus because they had had limited exposure to the measles. Because their bodies couldn’t sufficiently combat the measles virus, the virus has time to fight the cancer. Many individuals have antibodies to measles, and it is unclear how effective this treatment will be for them.
About 24,050 new cases of multiple myeloma will be diagnosed in 2014, according to the American Cancer Society. Men are more likely to get the disease than women, and the risk of getting myeloma increases with age.
While the complete remission of one patient’s cancer shows that virotherapy is promising in the fight against multiple myeloma, more research is needed. More of the MV-NIS treatment is being manufactured for a larger, phase 2 clinical trial, according to a statement from the Mayo Clinic.
These research findings appear in Mayo Clinic Proceedings. The investigation was supported by the National Institutes of Health-National Cancer Institute, Al and Mary Agnes McQuinn, The Harold W. Siebens Foundation, and The Richard M. Schulze Family Foundation. Drs. Russell, Federspiel and Peng and Mayo Clinic have a financial interest in the technology used in the study.