A team of U.K. researchers from the University of Surrey and Royal Surrey County Hospital used a common cold virus to treat 15 patients with non-muscle invasive bladder cancer (NMIBC). The team recently published the trial results in the Clinical Cancer Research journal.
Overall, the study produced positive outcomes. In one patient, the virus eradicated the tumor.
Current Treatment Options
According to the American Cancer Society, about 80,470 new cases of bladder cancer will occur in the United States in 2019, with the disease claiming about 17,670 lives. Furthermore, nearly half of all bladder cancers get discovered while the disease is contained inside the inner layer of the bladder wall (aka non-invasive cancer).
In early-stage bladder cancer, surgeons often remove tumors. However, more tumors can form in different parts of the bladder over time. Therefore, sometimes patients have a radical cystectomy (complete bladder removal) as a preventative measure.
However, this procedure carries risks such as bleeding, blood clots, infection, and heart attack, among others. Moreover, other organs might require removal, along with the bladder.
Non-surgical cancer treatments include chemotherapy, radiation, intravesical therapy, and more. In all forms of treatment, a relapse of the disease can occur.
“Non-muscle invasive bladder cancer is a highly prevalent illness that requires an intrusive and often lengthy treatment plan,” said Hardev Pandha, lead investigator of the study and Professor of Medical Oncology at the University of Surrey in a press release. “Current treatment is ineffective and toxic in a proportion of patients, and there is an urgent need for new therapies.”
The U.K. research team’s clinical trial may have provided a promising treatment alternative.
Cancer-Killing Cold Virus
Study participants received a strain of the common cold virus called “coxsackievirus” (CVA21). Researchers injected the virus straight into trial members’ bladders via a catheter, one week before surgery.
Remarkably, the patients’ post-surgery tissue samples showed the virus only infected (and attacked) cancerous cells. Healthy tissues remained intact. Furthermore, upon analyzing patient urine samples, researchers discovered the cold virus continued replicating and infecting more cancerous cells.
Even more astounding, one trial patient showed no signs of cancer at all during surgery, after receiving viral therapy for only a week.
Pandha commented on the potentially game-changing clinical results saying, “Coxsackievirus could help revolutionize treatment for this type of cancer. Reduction of tumor burden and increased cancer cell death was observed in all patients and removed all trace of the disease in one patient following just one week of treatment, showing its potential effectiveness.”
Unfortunately, bladder tumors are commonly “shielded” from the human immune system. As such, it can’t spontaneously attack these “cold” immune tumors. Therefore, researchers aim to find ways to make these “cold” tumors become “hot” tumors that can respond well to immunotherapy.
In the U.K. bladder cancer trial, the study team believes that the CVA21 virus inflamed the tumor cells, which prompted a rush of cancer-killing immune cells that made the tumors “hot” before the virus destroyed them.
Other Viral Treatments
Researchers have used viruses to fight cancer cells in different types of cancer. In the first-ever FDA-approved viral therapy called T-VEC, a modified form of the herpes simplex virus type 1 (HSV-1) effectively attacked melanoma cells.
In this treatment, doctors injected the virus directly into a tumor. As with the bladder cancer trial, the herpes virus attacked the cancer cells. The virus caused some cancerous cells to rupture. In other instances, the infection stimulated the immune system to attack the tumors and make them “hot.”
Another clinical trial used an oncolytic virus to treat patients with brain tumors. “Oncolytic virus therapy is of growing interest to researchers for one reason: It’s working,” said Juan Fueyo, M.D., of the University of Texas MD Anderson Cancer Center in a National Cancer Institute report. Fueyo co-developed the Delta-24-RGD used in the brain tumor study.
Beyond viral treatments, numerous technological advances are making strides in fighting cancer. For example, MIT researchers developed an AI assistant to manage treatments for glioblastoma patients. Nanomedicine, which is another emerging field of study, uses engineered nanoparticles to treat cancer.
Overall, cancer diagnosis and treatment options continue to evolve as scientists work to fight the deadly disease. The U.K. bladder cancer study offered promising results. However, researchers need to conduct long-term follow-up on trial patients, and they should run a larger trial to validate findings.
Research Fellow at the University of Surrey and the first author of the study, Dr. Nicola Annels, spoke favorably of the trial results in a statement. “Oncolytic viruses such as the coxsackievirus could transform the way we treat cancer and could signal a move away from more established treatments such as chemotherapy,” she said.