“Non-muscle invasive bladder cancer is a highly prevalent illness that requires an intrusive and often lengthy treatment plan,” stated Hardev Pandha, lead investigator and Professor of Medical Oncology at the University of Surrey, reported Forbes. “Current treatment is ineffective and toxic in a proportion of patients and there is an urgent need for new therapies.”
It’s possible that an immunotherapy utilizing a common cold virus might be a new therapeutic to battle bladder cancer. A group of researchers at the University of Surrey, UK, conducted a clinical trial of 15 patients with non-muscle invasive bladder cancer. The patients were treated with a virus called CVA21, or ICAM-1-targeted immunotherapeutic-coxsackievirus A21. The CVA21 virus is a common cold virus. The trial was published in the journal Clinical Cancer Research. The approach was dubbed CAVATAK.
“Non-muscle invasive bladder cancer is a highly prevalent illness that requires an intrusive and often lengthy treatment plan,” stated Hardev Pandha, lead investigator and Professor of Medical Oncology at the University of Surrey, reported Forbes. “Current treatment is ineffective and toxic in a proportion of patients and there is an urgent need for new therapies.”
Patients in the trial received CVA21 directly into their bladders by way of a catheter a week before surgery. After surgery, the researched studied tissue samples and found that the CVA21 virus only infected cancer cells, not healthy tissues. In addition, urine samples showed that the virus continued to grow and attack more cancerous cells. One patient was cancer free one week after receiving the treatment.
“Coxsackievirus could help revolutionize treatment for this type of cancer,” Pandha stated. “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.”
Non-muscle invasive bladder cancer, according to the American Cancer Society, affects approximately 40,000 people in the U.S. every year. Current treatments are very invasive, have serious side effects and patients often relapse. The recurrence rate ranges from 50% to 70%.
In the trial, of the 15 patients, the first nine received intravesical doses of monotherapy CAVATAK. In the second stage, six patients received CAVATAK with a sub-therapeutic dose of mitomycinC, which enhances expression of ICAM-1 on bladder cancer cells.
The researchers wrote, “Clinical activity of CAVATAK was demonstrated by induction of tumor inflammation and hemorrhage following either single or multiple administrations of CAVATAK in multiple patients, and a complete resolution of tumor in one patient. Whether used alone or in combination with mitomycinC, CAVATAK caused marked inflammatory changes within NMIBC tissue biopsies by up-regulating interferon-inducible genes including both immune checkpoint-inhibitory genes (PD-L1 and LAG3) and Th1-associated chemokines as well as induction of the innate activator RIG-I, compared to bladder cancer tissue from untreated patients.”
What appears to have happened is the virus selectively attacks the cancer cells, but also inflames them so that the immune system identifies and attacks. The researchers reported an acceptable safety profile.
If effective in larger trials, using viruses as a way to light up cancer cells along with the use of immuno-oncology therapies, could provide a new avenue for cancer treatments. This trial was a Phase I study whose primary goal was the evaluation of safety and dosage. The results to date are positive, with no toxicities or adverse effects observed and significant clinical benefits.
Other studies have evaluated CVA21 as potential treatments in melanoma and prostate cancer.
