Investigational Regenerative Therapy Shows Success in Complex Radiation Wound Treated by OU Health Physician

Experts at OU Health have successfully used a regenerative therapy currently being studied in clinical trials to heal a complex chronic wound that resisted all standard treatments — a breakthrough that underscores the innovative care available at Oklahoma’s flagship academic health system.

The therapy, called Purified Exosome Product (PEP™), is currently under evaluation in ongoing FDA-regulated clinical studies and is not yet available commercially. In this case, it was provided under the FDA’s Expanded Access Program for compassionate use in a single patient. OU Health’s use of this therapy highlights its commitment to academic-driven care and advancing solutions for patients facing the most challenging conditions.

The patient, Jim Everest, a three-time cancer survivor first diagnosed in the 1990s, developed a severe soft tissue wound in March 2023. The wound was caused by radiation damage during his cancer treatment, decades after undergoing extensive therapy that included radiation and the surgical removal of his voice box (a procedure called a total laryngectomy). Despite months of antibiotics, in-office and formal surgical debridement, and 30 hyperbaric oxygen sessions, the wound failed to heal and progressively worsened.

“It started as barely more than a scratch on the neck,” said OU Health Stephenson Cancer Center head and neck surgeon Dr. Greg Krempl, M.D., FACS, professor and chair of the Department of Otolaryngology at the University of Oklahoma College of Medicine.

“But over the course of weeks and months, it evolved into a deep, open wound. The tissue was so damaged from prior radiation that the normal healing process simply didn’t occur.”

Everest described the wound as alarming.

“The deep wound was not only unsightly but was spawning numerous infections with an almost nauseating smell,” he said. “The many antibiotics I received were wearing me down, not to mention worrying about how we might be able to stop the deterioration.”

With no viable surgical reconstruction options because of previous surgery and poor blood flow, Krempl turned to regenerative therapy. After learning about PEP, he initiated FDA authorization for compassionate use.

PEP Biologic is a platelet-derived regenerative medicine product invented at the Mayo Clinic under the Van Cleave Cardiac Research Program and further developed by RION. It uses extracellular vesicles — tiny carriers of biological signals — derived from platelets to promote regeneration of damaged tissues. These vesicles, often called exosomes, help stimulate tissue repair and regeneration by delivering healing signals directly to damaged cells. In this treatment, the exosomes are combined with a fibrin sealant, a gel-like substance that helps keep the therapy in place within the wound, allowing for a more sustained and effective healing process.

Everest’s treatment consisted of weekly applications over 16 weeks, starting on October 18, 2024, followed by an FDA-approved extension for eight additional treatments.

“Each visit involved applying local anesthetic, debriding and cleaning the wound, preparing the product, and dressing the area,” Krempl said. “It was a rigorous protocol, but one that ultimately yielded impressive results.”

By April 2025, the wound had stopped draining and was 95% closed. In June, for the first time in nearly two years, Everest no longer required a bandage and new skin covered the entire wound.

“Without this therapy, he would have likely lived with an open wound for the rest of his life with regular infections,” Krempl said. “Traditional surgery simply wasn’t possible in his case.”

Everest said the treatment gave him a renewed sense of freedom.

“The fact that OU Health specialists saw a difficult situation and found a solution says it all,” he said.

While regenerative therapy may not be appropriate for all wound types, Krempl believes this case highlights potential for broader applications in complex wound care. By November 2025, Everest’s wound was filling in with new tissue growth, reducing the size of the sunken area.

“These scenarios are rare, but when standard treatments fail and tissue damage is severe, regenerative therapies like PEP offer hope,” said Krempl, who plans to publish a case report to further evaluate and share findings. “This took an impossible situation and gave us a closed wound. That’s no small thing.”

To learn more about RION and PEP Biologic therapy, visit www.riontx.com.