OKLAHOMA CITY (KFOR) – When it comes to successfully treating patients with cancer, researchers say one of the biggest challenges is targeting all cancer cells in their body.
Officials say antibody-based immunotherapy drugs have shown promising results in treating lung cancer by allowing the body’s own immune cells to fight off the disease. However, most patients either respond initially and then develop resistance, or they don’t respond to the treatment at all.
One Oklahoma researcher believes that the resistance is due to cancer cells being able to possibly coat the surface of an immunotherapy antibody, which then neutralizes its ability to detect the tumor cells.
“We believe that these cancer cell exosomes, through PD-L1, are covering up the antibody, and because of that, it never sees the actual tumor cell,” said Rajagopal Ramesh, Ph.D., is a researcher at Stephenson Cancer Center at OU Medicine. “So the tumor cells continue to grow.”
Ramesh says he is studying a small group of about 25 patients in real-time as they are receiving an immunotherapy medication.
“If that correlation proves to be true, then we have a better understanding of this mechanism of treatment resistance, which gives us starting point to intervene in that process,” Ramesh said. “Then we can think about ways to perhaps reduce the production of cancer cell exosomes or develop another strategy to avoid resistance to immunotherapy. Also, if we demonstrate this to be true, it can be applicable to any type of cancer in which immunotherapy is used as a treatment, not just lung cancer.”
If he proves his concept, he will expand to a larger group of patients and follow them for up to two years, then leverage his findings for additional federal grants.
Recently, he received a grant from the U.S. Department of Defense for his work.