Virotherapy recently became touted as a new landmark in destroying cancer after 50-year old Stacy Erholtz, chose to participate in an experimental trial at the world-renowned Mayo Clinic. Lead researcher, Dr. Stephen Russell, a professor of molecular medicine, commented that this is now proof that this type of therapy can be done in humans. Although researchers do stress that human trials are still in early stages, they are calling this a proof of principle that when cancer receives a blast of high dose measles virus that has been specially engineered, it can work, as it did for Erholtz.
Stacy Erholtz had been in a battle with blood cancer that affected the bone marrow, known as myeloma. After undergoing two stem cell transplants, along with chemotherapy treatment, she was willing to try anything. The effect was that this cancer had been growing tumors all over her body. She even had one growing on her forehead, which was pushing in on her brain as a result of a bone that was being destroyed in her skull. Her children named this tumor Evan. It was apparent that her bone marrow was saturated with cancer, which is why these tumors were erupting all over her body.
The doctors at Mayo Clinic were offering a two-patient clinical trial. A total of 100 billion units of the measles virus, enough to inoculate 10 million people, was injected into Erholtz. She and the doctors knew that they were entering into unchartered territory. Although the method had been proven to work in mice, it was totally unknown as to how her (or any other person’s) body would respond.
The injection was an hour-long process, but five minutes in, she got a horrific headache. Shaking and vomiting began two hours later, and then her temperature rose to 105 degrees. This process was monitored by Dr. Russell, and 36 hours after the virus was finished, “Evan” began to shrink. That tumor, as well as all of the other tumors disappeared over the next several weeks. The virus had been engineered by Russell and a team of researchers to make it more palatable for therapies targeting this specific type of cancer. Erholtz’s cancer went into remission after just one inoculation. Russell wrote in the Mayo Clinic journal Proceedings, that there is no more disease to be found.
The Mayo Clinic released a statement on Wednesday, that virotherapy, can be effective against the deadly cancer multiple myeloma. Virotherapy defined, is the destroying of cancer with a virus that infects and kills the cancer cells, but will spare normal tissues. Oncolytic virotherapy, dating back to the 1950s, is the use of re-engineered viruses to fight cancer. Although thousands of patients have been treated through the years with oncolytic viruses from different virus families, this new study provides the first well-documented case where the patient, after virus administration, went into complete remission.
Dr. Russell said that this is an important landmark because it tells them something that they never knew before: this can be effective for people. He feels that this will drive development further into this field of study. According to Russell, two things were taught to the researchers in this trial: the patient cannot have an antibody to the virus; and a really large dose is needed. So, destroying cancer through virotherapy is a new landmark in the future of cancer treatment.
Since this trial only included two patients, it was unfortunate that the treatment in the other patient was unsuccessful. The tumors in the other patient were in her leg muscles, so that tells doctors that more information is needed about the nature of the tumor and how it ultimately affects the virus. As for Erholtz, she is six-months cancer free.
Typically, patients with myeloma have weakened immune systems, and that is what allows the virus to work. Future trials will look at the breaking down of the immune system before treatment begins. It is hopeful that this technique of virotherapy will become a standardized treatment for cancers like myeloma or pancreatic cancer. Much work lies ahead as large randomized clinical trials are needed to confirm this study. Tanios Bekaii-Saab, who is a researcher at James Cancer Hospital and Solove Research Instititute in Ohio, said that they are cautiously optimistic.
Dr. Russell confirms that this is a very simple concept. In this case, since multiple myeloma is a cancer of plasma cells, a specific single dose of an engineered measles virus was targeted because it was selectively toxic to the myeloma plasma cells, which had caused the skeletal or soft tissue tumors. Science is hopeful that they could be moving toward a “single shot cure” for cancer, which would truly be a game changer in the field of medicine. Hope marches forward as a treatment through virotherapy stamps a new landmark in the destruction of cancer.
By Jill Boyer-Adriance