A segment on last Sunday’s edition of 60 Minutes highlighted the remarkable effects of injecting poliovirus into brain tumors. Three years after receiving the poliovirus treatment at the Preston Robert Tisch Brain Tumor Center at Duke University, a young woman featured in the program remains cancer-free and has just graduated from nursing school. Her glioblastoma, an aggressive and treatment-resistant brain cancer, has shown no signs of returning. Is she cured? She and her doctors certainly hope so!
What do these results mean for myeloma patients? Unfortunately, the poliovirus is too toxic and dangerous to be used in the bloodstream to target myeloma in the bone marrow. However, other carefully selected and engineered viruses show promise in treating myeloma. This is known as “systemic virotherapy,” in contrast to injecting a virus directly into a localized tumor, such as a brain tumor.
We’ve seen promising early results using an engineered version of the measles virus, the same virus used for vaccination, adapted to attack myeloma. Similar to the poliovirus trial, the measles virus dose was gradually increased to assess both safety and effectiveness. In this phase I study, three patients were treated at each dose level before escalating to the next dose, while monitoring for safety. Striking the balance between effective responses and ensuring safety is challenging. As shown in the 60 Minutes segment, the lower dose of poliovirus worked remarkably well for the young woman, but it triggered significant immune responses, including brain swelling and inflammation as the cancer was destroyed. Higher doses in later patients caused excessive swelling and inflammation, leading to critical complications.
These early trials with novel treatments demand careful caution.
So, do these viruses work against cancer, and what is the optimal dose? For the measles virotherapy, a phase II study began at the Mayo Clinic in the fall of 2014. Dr. Martha Lacy from the Mayo Clinic recently mentioned at the San Francisco IMF Patient & Family Seminar that about a dozen patients have been treated so far, though official results have not yet been released. One challenge is that most patients already have antibodies from the measles vaccine, which can block the virus, causing high fevers and other side effects like headaches. Researchers are eager to learn more about the progress of this trial, led by Dr. Stephen Russell and the Mayo Clinic team.
In the meantime, the Mayo team is preparing to launch a trial with another virus that may be a safer option for systemic virotherapy in myeloma treatment. The vesicular stomatitis virus (VSV), which can cause blistering of the lips like herpes, has shown potential. Because the body does not have antibodies against VSV, all myeloma patients are eligible for treatment. Laboratory studies suggest that VSV could be even more effective than the measles virus, making it a very promising option. If FDA approval comes through, clinical trials are expected to begin later this year.
What does this mean for myeloma patients? The potential of viral therapy is significant. Dr. Russell has described the approach as a possible “one-shot cure,” with some patients experiencing remarkable benefits after just one IV infusion. While it’s still too early to know the full impact, the possibilities are exciting.
This research represents a bold new frontier, with hope for a cure on the horizon. As we watch this progress unfold, we can look ahead with optimism.
