Radiologist and researcher Jason Williams, MD, claims to have found a new solution to the spiraling costs of cancer treatments: inject immunotherapy drugs directly into cancerous tumors after using image-guided cryoablation.
Although immunotherapies, such as ipilimumab (Yervoy, Bristol-Myers Squibb) and pembrolizumab (Keytruda, Merck), are effective at manipulating the body’s immune system to fight cancer, they are also expensive. The average cost of using these drugs in combination at a standard dose is approximately $300,000 per year.
Animal research has shown that combining the injection of immunotherapy drugs with cryoablation of the tumor improves survival rates by more than 80%, according to Dr. Williams. The ablation process kills the tumor, releasing tumor antigens to stimulate an anticancer immune response. However, this immune stimulation is rarely strong enough to generate a curative response until immune checkpoint-inhibitor drugs are added, he says.
“Biologically, the idea makes sense because intentionally leaving dead tissue for the body to dispose of naturally is a way to potentially immunize against cancer cells,” says Alex Y. Huang, MD, PhD, an Associate Professor at Case Western Reserve University School of Medicine. “Cryoablation uses cold temperature to induce necrotic cell death, which is a signal for the immune system to wake up. The dead tumor proteins will be seen as foreign by the immune system, which will attack the cancer.”
Dr. Williams’ method is novel because after freezing and killing those cells, he then uses image-guidance technology to put probes into the remaining tumor. Then, instead of surgically removing the cancerous growth, he injects the immunotherapy drugs directly into the problematic tissue.
“This has the double benefit of activating the local immune system against cancer in other locations, without globally activating the immune system against the patient’s healthy tissue,” Dr. Huang remarks. “The risk of hitting the wrong tissue is low, and we know these drugs are safe at much higher systemic rather than smaller, targeted doses. The potential for systemic toxicity is lower, and because the drugs are given only locally, the cost is vastly reduced.”
Animal models have shown that one-eighth of the typical intravenous dose is required when using local injections. Therefore, if a therapy costs $300,000 per year, the same clinical efficacy could be achieved for $37,500 worth of drug, Dr. Williams claims.
He has used his method to treat approximately 80 patients in Mexico, including one woman with advanced breast cancer who had more than 30 tumors in the lungs, bones, and brain.
“A single treatment ablated two lung tumors and, using combination immunotherapy, she had complete resolution of the tumors in the body and 50% reduction in [the] size and number of the brain tumors,” Dr. Williams says.
His method has not been tested in a controlled clinical trial.