Stem cell therapy for diabetic foot ulcers shows promise in new study

For individuals with diabetes, the body’s inability to properly control blood sugar levels can lead to a wide range of other problems as time passes. One major issue is a diabetic foot ulcer (DFU), an open sore or wound that is commonly located on the bottom of the foot and caused by poor blood circulation and nerve damage. It occurs in approximately 15% of individuals with diabetes and in severe cases can lead to foot or leg amputation. Unfortunately, there is usually no effective form of treatment for this condition.

However, results from several studies authorized by the Ministry of Health of Nicaragua showed that using a stem cell therapy to treat patients with DFUs was safe and could be beneficial to patients.

The first results in a pilot study after an 18-month period demonstrated safety of the therapy and complete wound healing by nine months. After the six-year mark, five of the initial 10 subjects still demonstrated persistence of clinical benefits. It should be noted that five had passed away due to cardiac and other non-study-related causes.

In another study, the team wanted to determine the safety and efficacy of the stem cell therapy to treat non-healing DFUs greater than 3 centimeters in diameter.

For this clinical trial, 63 people from 35 to 70 years old with Type 2 diabetes and chronic DFU, all of whom were amputation candidates, were treated with a mixture of various types of stem cells obtained from the patient’s own fat tissue. The stem cell therapy was injected directly into the DFU with the hopes of restoring damaged blood vessels and promoting blood circulation and healing.

Patients were seen six months post treatment to evaluate ulcer closure, with 51 patients achieving 100 percent DFU closure and eight having greater than 75 percent. Only three required early amputations and one patient died. At 12 months post treatment, 50 patients had 100 percent DFU healing, while four had greater than 85 percent healing.

In a news release, Dr. Anthony Atala, Director of the Wake Forest Institute for Regenerative Medicine, expressed interest in evaluating this stem cell therapy and results further.

“This work should be reviewed as it demonstrates the possibility of a novel cell injection therapy that can alleviate pain and infection, accelerate wound healing, and possibly avoid amputation.”

The full results of the recent study were published in Stem Cells Translational Medicine.

Partners in health

From left to right: Heather Dahlenburg, Jan Nolta, Jeannine Logan White, Sheng Yang
From left to right: Heather Dahlenburg, staff research associate; Jan Nolta, director of the Stem Cell Program; Jeannine Logan White, advanced cell therapy project manager; Sheng Yang, graduate student, Bridges Program, Humboldt State University, October 18, 2019. (AJ Cheline/UC Davis)

At CIRM we are modest enough to know that we can’t do everything by ourselves. To succeed we need partners. And in UC Davis we have a terrific partner. The work they do in advancing stem cell research is exciting and really promising. But it’s not just the science that makes them so special. It’s also their compassion and commitment to caring for patients.

What follows is an excerpt from an article by Lisa Howard on the work they do at UC Davis. When you read it you’ll see why we are honored to be a part of this research.

Gene therapy research at UC Davis

UC Davis’ commitment to stem cell and gene therapy research dates back more than a decade.

In 2010, with major support from the California Institute for Regenerative Medicine (CIRM), UC Davis launched the UC Davis Institute for Regenerative Cures, which includes research facilities as well as a Good Manufacturing Practice (GMP) facility.

In 2016, led by Fred Meyers, a professor in the School of Medicine, UC Davis launched the Center for Precision Medicine and Data Sciences, bringing together innovations such as genomics and biomedical data sciences to create individualized treatments for patients.

Last year, the university launched the Gene Therapy Center, part of the IMPACT Center program.

Led by Jan Nolta, a professor of cell biology and human anatomy and the director of the UC Davis Institute for Regenerative Cures, the new center leverages UC Davis’ network of expert researchers, facilities and equipment to establish a center of excellence aimed at developing lifelong cures for diseases.

Nolta began her career at the University of Southern California working with Donald B. Kohn on a cure for bubble baby disease, a condition in which babies are born without an immune system. The blood stem cell gene therapy has cured more than 50 babies to date.

Work at the UC Davis Gene Therapy Center targets disorders that potentially can be treated through gene replacement, editing or augmentation.

“The sectors that make up the core of our center stretch out across campus,” said Nolta. “We work with the MIND Institute a lot. We work with the bioengineering and genetics departments, and with the Cancer Center and the Center for Precision Medicine and Data Sciences.”

A recent UC Davis stem cell study shows a potential breakthrough for healing diabetic foot ulcers with a bioengineered scaffold made up of human mesenchymal stem cells (MSCs). Another recent study revealed that blocking an enzyme linked with inflammation enables stem cells to repair damaged heart tissue. A cell gene therapy study demonstrated restored enzyme activity in Tay-Sachs disease affected cells in humanized mouse models.

Several cell and gene therapies have progressed to the point that ongoing clinical trials are being conducted at UC Davis for diseases, including sickle-cell anemia, retinopathy, muscle injury, dysphasia, advanced cancer, and Duchenne muscular dystrophy, among others.

“Some promising and exciting research right now at the Gene Therapy Center comes from work with hematopoietic stem cells and with viral vector delivery,” said Nolta.

Hematopoietic stem cells give rise to other blood cells. A multi-institutional Phase I clinical trial using hematopoietic stem cells to treat HIV-lymphoma patients is currently underway at UC Davis.

.Joseph Anderson

Joseph Anderson

“We are genetically engineering a patient’s own blood stem cells with genes that block HIV infection,” said Joseph Anderson, an associate professor in the UC Davis Department of Internal Medicine. The clinical trial is a collaboration with Mehrdad Abedi, the lead principal investigator.

“When the patients receive the modified stem cells, any new immune system cell, like T-cell or macrophage, that is derived from one of these stem cells, will contain the HIV-resistant genes and block further infection,” said Anderson.

He explained that an added benefit with the unique therapy is that it contains an additional gene that “tags” the stem cells. “We are able to purify the HIV-resistant cells prior to transplantation, thus enriching for a more protective cell population.

Kyle David Fink

Kyle David Fink

Kyle David Fink, an assistant professor of neurology at UC Davis, is affiliated with the Stem Cell Program and Institute for Regenerative Cures. His lab is focused on leveraging institutional expertise to bring curative therapies to rare, genetically linked neurological disorders.

“We are developing novel therapeutics targeted to the underlying genetic condition for diseases such as CDKL5 deficiency disorder, Angelman, Jordan and Rett syndromes, and Juvenile Huntington’s disease,” said Fink.

The lab is developing therapies to target the underlying genetic condition using DNA-binding domains to modify gene expression in therapeutically relevant ways. They are also creating novel delivery platforms to allow these therapeutics to reach their intended target: the brain.

“The hope is that these highly innovative methods will speed up the progress of bringing therapies to these rare neurodegenerative disease communities,” said Fink.Jasmine Carter, a graduate research assistant at the UC Davis Stem Cell Program.

Jasmine Carter, a graduate research assistant at the UC Davis Stem Cell Program, October 18, 2019. (AJ Cheline/UC Davis)

Developing potential lifetime cures

Among Nolta’s concerns is how expensive gene therapy treatments can be.

“Some of the therapies cost half a million dollars and that’s simply not available to everyone. If you are someone with no insurance or someone on Medicare, which reimburses about 65 percent, it’s harder for you to get these life-saving therapies,” said Nolta.

To help address that for cancer patients at UC Davis, Nolta has set up a team known as the “CAR T Team.”

Chimeric antigen receptor (CAR) T-cell therapy is a type of immunotherapy in which a patient’s own immune cells are reprogrammed to attack a specific protein found in cancer cells.

“We can develop our own homegrown CAR T-cells,” said Nolta. “We can use our own good manufacturing facility to genetically engineer treatments specifically for our UC Davis patients.”

Although safely developing stem cell treatments can be painfully slow for patients and their families hoping for cures, Nolta sees progress every day. She envisions a time when gene therapy treatments are no longer considered experimental and doctors will simply be able to prescribe them to their patients.

“And the beauty of the therapy is that it can work for the lifetime of a patient,” said Nolta.