In what they describe as a proof of principle study, doctors in the US were able to keep a woman with deadly multiple myeloma - an incurable bone marrow cancer - free of all signs of living cancer cells for over 6 months by giving her just one high dose of measles virus.
The team, from the Mayo Clinic in Rochester, MN, says both patients responded to the treatment, showing reduced bone marrow cancer and levels of myeloma protein.
But one patient, a 49-year-old woman, experienced complete remission and remained disease-free for over 6 months.
A report on this first study to establish the feasibility of the treatment appears in the journal Mayo Clinic Proceedings.
Proof virotherapy works for disseminated cancer
First author Dr. Stephen Russell, hematologist and co-developer of the therapy, says:
"This is the first study to establish the feasibility of systemic oncolytic virotherapy for disseminated cancer. These patients were not responsive to other therapies and had experienced several recurrences of their disease."
The treatment is an example of oncolytic virotherapy - using engineered viruses to fight cancer - an approach that dates back to the 1950s. Thousands of patients have received this type of therapy, using oncolytic viruses from various families, including common cold viruses, herpes viruses and pox viruses.
But the authors say this is the first well-documented case of a patient with cancer that has spread experiencing complete remission at all disease sites after receiving oncolytic virus therapy.
The video below details the patient's treatment and remission:
Myeloma is a cancer that develops in plasma cells - a type of blood cell made in the bone marrow. According to the American Cancer Society, the disease is relatively uncommon, and in the US, there is a 1 in 149 risk of developing it.
Myeloma can arise in any part of the body where there is bone marrow, including the spine, rib cage and pelvis. Multiple myeloma means it is occurring in more than one place.
The disease, which also causes skeletal or soft tissue tumors, usually responds to drugs that stimulate the immune system, but it eventually overcomes them and is rarely cured.
First use of highest possible dose of engineered measles virus
Dr. Russell and colleagues explain in their article that they chose to report these two cases in particular because they were the first patients they had studied who had received the highest possible dose, and with limited previous exposure to measles, so their immune systems did not have many antibodies to the virus. They had also exhausted other treatment options.
Senior author Dr. Angela Dispenzieri, an expert in multiple myeloma, says in very simple terms, the measles virus makes the cancer cells join together and explode. The treatment also appears to trigger another lasting benefit:
"There's some suggestion that it may be stimulating the patient's immune system to further recognize the cancer cells or the myeloma cells and help mop that up more effectively than otherwise."
Having effectively completed a phase I clinical trial - to prove the concept that the measles virus can fight cancer - the team is now moving quickly into a phase II trial involving more patients.
They also intend to test the virus's effectiveness as a tool to fight other cancers, such as head and neck, brain and ovarian cancers and mesothelioma. And they are engineering other viruses that may be able to kill cancer cells.
Dr. Russell says they have recently started to think along the lines of "a single shot cure for cancer, and that's our goal with this therapy."
He and two other authors of the study, as well as the Mayo Clinic, have declared a financial interest in the methods used in the study, which was funded by the National Cancer Institute of the National Institutes of Health, Al and Mary Agnes McQuinn, The Harold W. Siebens Foundation and The Richard M. Schulze Family Foundation.
Medical News Today recently reported on a study in Nature Genetics, where scientists from The Institute of Cancer Research in the UK found a gene involved in aging is linked to multiple myeloma. The team said the discovery brings the total genetic variants linked to myeloma to seven and may help establish the genetic causes of the disease.
Written by Catharine Paddock PhD