Why do some cancer drugs work with them and not others?
W. Hen researchers are conducting a clinical trial on a new cancer drug, and the treatment often doesn’t work for most patients. But sometimes a particular patient responds so well that the cancer stops growing or even disappears completely. These patients are so unique that scientists have a special name for them: rhinoceros. Also known as exceptional responders, these extraordinary patients are now the subject of extensive research on why they show such positive responses when others don’t, and how learning can help other patients.
“This is the Holy Grail of cancer treatment – finding what makes these patients unique. It is the miracle solution that can help fight cancer in a particular patient.” – Arturo Loaiza-Bonilla, MD, MSEd, FACP – Chief, Clinical Oncology and Medical Director for Research at our Hospital in Philadelphia
Study sheds new light
In the past, if only 1 in 10 patients responded to a new drug, researchers assumed that the treatment was not effective for this type of cancer and would cut off this type of research. But a study published in 2012 changed conventional thinking about exceptional responders. The study indicated that a patient with advanced bladder cancer who participated in a clinical trial had a “remarkable response” to targeted therapy that was clearly distinct from the other 44 participants in the trial. So the researchers decided to dig deeper. After molecular testing of a woman’s tumor DNA, researchers discovered two rare gene mutations in most bladder cancer patients. But when mutations are present, they make the tumor more receptive to treatment.
Researchers have already found that 10 to 20 percent of tumors in exceptional responders have an unusually high number of genetic mutations, which can make tumors more likely to respond to immunotherapy drugs. Eso significa que la identificación de biomarcadores predictivos, o mutaciones de ADN únicas en las células tumorales de respondedores excepcionales, puede ayudar a los investigadores a diseñar medicamentos para atacar esas misón el tumor tumor mutaciones de encuentes en sépendes the body. “We now know that when your tumor has a certain characteristic, it is more likely to respond to immunotherapy, which is why it will do so much better,” says Dr. Bonilla. “Patients have this advantage that they did not have before.”
How can advanced genomic testing help?
Armed with this new knowledge, experts encourage patients to talk with their doctor about advanced genomic testing if their cancer doesn’t respond to standard treatments. “Patients need to be their advocate,” says Dr. Bonilla. “When I examined some patients who had not responded to chemotherapy, for example, I found that they had a specific DNA mutation in their tumor which meant they were candidates for a certain type of immunotherapy drug, which we wouldn’t do. I didn’t know otherwise.” Testing patients’ tumors has an additional benefit to the research world and possibly other patients.
Dr. Bonilla adds: The more researchers conduct biomarker tests, the more likely the scientific community will identify exceptional responders. “The more exceptional responders we study, the more we can customize treatments to help more people,” says Dr. Bonilla.