Testing a promising treatment for radiation-induced dry mouth

At the time those shakes were the only thing Marks, of Stoughton, could eat because of the pain and constant dry mouth he suffered after radiation treatment for a tumor found on his tongue.

“From June until October (of 2019) it was too painful to eat food,” he said.

Acupuncture helped with the pain, but his inability to produce adequate saliva continued. That chronic dry mouth impacted many day-to-day activities for Marks and caused dental issues that led to two teeth being removed.

Dry mouth, also called xerostomia, is an extremely common side effect of radiation treatments for head and neck cancer because of the damage and scar tissue to salivary glands. Dr. Randall Kimple, a radiation oncologist at UW Health | Carbone Cancer Center who treats head and neck cancer patients, is working to address this crucial survivorship need. Kimple is principal investigator on a new phase I clinical trial evaluating a cell therapy treatment developed at UW to increase saliva production.

“You don’t think about how important saliva is to you until it’s gone, and that’s the issue our patients are left with,” Kimple said. “And the only treatment we have to offer to them right now is to tell them to drink more water.”

Kimple partnered with Dr. Jacques Galipeau, director of the Program for Advanced Cell Therapy (PACT) at UW, to explore use of stromal cells, which can form connective tissue, as a regenerative therapy for damaged salivary glands. Their approach takes stromal cells from a patient’s bone marrow, treats them with interferon gamma, and injects them into the patient’s salivary gland to rebuild function.

Based on promising results from a pilot study with six patients, Kimple and his collaborators have now received Food and Drug Administration approval to expand their work in a phase I clinical trial.

“I think it’s really important to focus on life after cancer as well as treating cancer, and that’s where this research really falls—life after cancer,” he said. “If there’s something that can make it better, even a little improvement can go a long way.”

Marks was part of the pilot study of this treatment. He recalled that, at the outset, they collected baseline samples of current saliva production. He said he barely cleared half an inch in the test tube after a few minutes. After the injection, he noticed a dramatic improvement.

“The first time they checked, I would say it tripled or quadrupled from the saliva I had initially,” he said. “The second time, they had to get a second test tube. Since then, it has stayed right at that level.”

Marks feels fortunate that he was able to participate in the study and get relief from his dry mouth issues.

“I’m just amazed at it,” he said of his improvement.

Kimple said there is also research ongoing with mice to study dose tolerability, as well as research into collecting stromal cells from the mouth prior to radiation treatment as an alternative to a bone marrow sample.

He praised the strong collaboration of experts from multiple fields to be able to start this research in a lab setting at UW and transition it to clinical research on-site.

“Because of the expertise on this campus and through Carbone, it’s a really unique opportunity that I don’t think could be replicated at very many places,” Kimple said.