Promising early results from a clinical trial at the Mayo Clinic out this week suggest that a modified version of the measles virus can be used to target cancer cells and put the condition into remission. Researchers intravenously delivered 10,000 times the typical dosage of measles vaccine to two women, 49- and 65-years-old, who had multiple myeloma, a rare cancer affecting white blood cells in bone marrow. The virus, which was modified to specifically target cancer cells, reduced or eliminated tumors in the two patients. The 49-year-old woman responded particularly well; other than one local relapse that was treated with radiotherapy, her tumors have disappeared and cancer has remained in remission for over six months.
The idea of using viruses to attack cancer isn't a new one — scientists have been studying the technique since the 1950s. However, researchers say that this is the first time they've been able eliminate cancer in a human subject using the virus through an intravenous injection. The virus was able to target the tumors itself and even treat affected bone marrow. Other similar studies have used direct injection into tumor sites rather than intravenous delivery methods.
"We believe it can become a single-shot cure."
That's part of what has the researchers particularly optimistic about the results. Dr. Stephen J. Russell, the study's lead author, said, "What we're really excited about with this particular approach is that we believe it can become a single-shot cure." Traditional cancer treatments require months of visits to continue battling the cancer cells. One hurdle for the technique, however, is that patients who've built up antibodies — close to 95 percent of the US public has been vaccinated to measles — are not eligible for the treatment. However, myeloma does weaken patients' immune systems, which makes the virus more effective.
Despite promise in the treatment, it's important to note that this is still extremely early. Other promising virus-based cancer treatments have been tested many times in the past but none have advanced far through clinical trials. Incredibly thorough trials with far more patients will be required as these results are far from definitive. Dr. Stephen Russell warned: "We have an enormous amount of work to do to determine if this is generalizable and how to best apply the approach to other cancer patients." He added, "We haven’t discovered a cure for cancer here."