June 24, 2022 by John Fernandez
Miami Cancer Institute CEO: Immunotherapy Clinical Trial That Resulted in Rectal Cancer Cure Is Future of Cancer Care
The recent announcement of a cure for all of the rectal cancer patients in a small clinical trial at Memorial Sloan Kettering (MSK) Cancer Center in New York has physician researchers worldwide astonished and hopeful.
“We have never seen a clinical trial where 100 percent of patients responded,” says Michael J. Zinner, M.D., CEO and executive medical director for Miami Cancer Institute, part of Baptist Health. “If we see 40 percent or 50 percent of patients respond, we think that’s an incredible result. Now they have to expand the trial to a much larger patient population.”
The trial involved 18 patients who underwent experimental immunotherapy to treat their rectal cancer. It’s important to note, Dr. Zinner says, that all of the patients had a specific mutation or genetic makeup called a mismatch repair-deficient (MMRd) or microsatellite instability (MSI). Fewer than 10 percent of the 45,000 Americans diagnosed with rectal cancer each year are believed to have this particular mutation, according to the American Cancer Society. The mutation occurs when a cell replicates but does not do so perfectly.
Although this trial was small, it shows the power and potential of targeted therapies and immunotherapy ― treatments that are being studied and used successfully at Miami Cancer Institute for some other cancers.
Years in development, these approaches reveal the direction in which cancer care is heading, Dr. Zinner says. “This is the definition of personalized cancer care. As we discover more of these biomarkers, we are going to get better and better at targeting cancer.”
The MSK study used dostarlimab, a drug known as an immune checkpoint inhibitor, given to the patients every three weeks for a period of six months. Immune checkpoint inhibitors are proving to be effective in certain types of cancers because of their ability to outsmart cancer cells.
“Cancers got very clever over time,” Dr. Zinner explains. “They could cloak themselves and be invisible to our immune system. It’s like Star Trek’s Klingon warships that could cloak themselves from their enemies. These immune checkpoint inhibitor drugs break that cloaking system.” No longer invisible, the cancer cells can be attacked and destroyed by the immune system.
Rectal cancer is most commonly treated with chemotherapy and radiation to shrink the tumor so that surgeons can then remove as much of the cancer as possible. In the MSK trial, in all cases, the cancer disappeared, eliminating the need for other treatment. “The results were spectacular,” Dr. Zinner says.
Dr. Zinner compares advances in cancer care to advances in the military. “For example, in the Vietnam Era, there used to be carpet-bombing over large areas,” he says. “We are no longer doing carpet-bombing. We are using laser-targeted missiles.”
Miami Cancer Institute is Florida’s only member of the Memorial Sloan Kettering Cancer Alliance, a collaboration that provides patients access to novel clinical trials in South Florida. The Institute has doubled the number of clinical trials each year since its opening in 2017. For more information on the Institute’s clinical trials, click here.