While most people pass their stool without a second thought, a team of UPMC researchers is using it to help improve immunotherapy treatments for cancer patients.
A group of more than 20 scientists in the UPMC Hillman Cancer Center in collaboration with the National Cancer Institute demonstrated a new way to advance immunotherapy through fecal matter transplants. The group, which began the study in 2016 and began clinical trials in early 2018, published the results of their phase II clinical trial in “Sciences” in early February.
The research team, led by Pitt scientists Diwakar Davar, MD, and Hassane Zarour, MD, and NCI’s Giorgio Trinchieri, MD, were looking for a way to improve immunotherapy treatments for patients with melanoma – a form of skin cancer. They inserted healthy gut microbes through injections into cancer patients to replace the “bad” gut microbes, which strengthened their immune systems.
Zarour, a cancer immunologist and professor of medicine at Pitt, said immunotherapy is a technique used to treat cancer in which a person’s immune system is activated or suppressed through your gut microbes. He said he hopes to use fecal matter transplants to help patients who don’t respond to traditional immunotherapy techniques.
“Cancer immunotherapy is becoming a revolutionary technique in the last 10 years and has been effective in many types of cancer, but almost half of patients respond to this therapy,” Zarour said. “What we’re trying to do is help the other half of the patients who don’t respond because we knew that the microbes, particularly the bacteria that you have in your gut, regulate immunity, including cancer immunity in the patient, so So I hope we can change the bad microbiomes in the gut to good microbiomes.”
Trinchieri, chief of the Cancer Immunology Section at NCI, said that while this application of fecal matter transplants is new to the field of oncology, fecal matter transplants have been used for years to treat diseases such as colitis, inflammatory bowel disease and intestinal infections. .
Trinchieri added that patients have had stool transplants in the past to help treat other conditions, but he does not recommend this treatment, nor does the Food and Drug Administration.
“These do-it-yourself methods are about 95 percent effective and because obviously, in theory, it’s something you could do on your own, and there are definitely people who have been doing it,” Trinchieri said. “But doing these procedures yourself in an uncontrolled way is something that can have a significant risk, and it is definitely an issue that should not be raised.”
In the clinical trial the team conducted, six of the 15 patients with advanced melanoma who received the stool treatment showed tumor shrinkage or disease stabilization lasting more than a year. Davar, medical oncologist and member of the Cancer Immunology and Immunotherapy Program at UPMC Hillman, said the research team hopes to expand the trial to more patients and investigate whether fecal matter transplants can also be applied to other cancers and melanomas.
“We also want to expand because our goal is for this treatment to be applied to more than one patient with melanoma or cancer,” said Davar, an assistant professor of medicine at UPMC. “Our ultimate goal is to identify the specific microbes that help build stronger immunity and turn them into some kind of pill or probiotic that cancer patients can take to boost their ability to fight disease.”
Although this research uncovered a new application for fecal matter treatments, Zarour said the team could not patent this research until the researchers identified an actual product or specific microbe that directly corresponds to more effective immunity, because matter transplants fecal are a commonly used procedure applied to a multitude of conditions.
“If we can precisely define a group of microbes that have not yet been identified for use as probiotics, then this would be potentially patentable, right, but the process itself is not patentable,” Zarour said.
Trinchieri said this research could have far-reaching applications and be used to treat cancers other than melanomas.
“I think that within the next 10 years we will be able to identify the specific set of microbes that help patients who cannot respond to treatments to increase their immunity and, hopefully, that this treatment will be applied to other types of cancer as well, to that patients who are struggling right now to respond to cancer treatments will have a fighting chance in the future,” Trinchieri said.