Clinical Research News

Thymosin Beta-4 and Chronic Wound Healing

First human trial tests thymic hormone in pressure sores

About three million people in the U.S., primarily elderly and bedridden, suffer from chronic pressure sores ("bedsores") that do not heal. These kinds of infections can result in loss of limbs or, in some cases, even death. Because they require such long-term care, the cost of treating just one pressure wound can range from $14,000 to $50,000.

When a chronic wound occurs, it is because the normal process of healing has been disrupted. Many factors may be responsible for such interruption, including infection, systemic causes such as diabetes, and the use of certain medications such as corticosteroids.

Standard treatments for pressure sores and diabetic ulcers include agents to debride them (remove dead tissue), topical agents such as antimicrobials and enzymes, and various types of dressings. Other options include treatment by Vacuum-Assisted Closure or surgery. But even with these advanced strategies, the recurrence rate for chronic wounds remains high. What is needed is a way to help the body heal once infections develop.

NewYork-Presbyterian Hospital/Columbia University Medical Center is addressing this challenge in a study on thymosin beta-4, a naturally occurring protein that can reduce inflammation and help wounds to heal. "Thymosin beta-4 is a major activator of actin, which improves the process of wound healing," says Mark A. Hardy, MD. Dr. Hardy is Auchincloss Professor of Surgery at Columbia University College of Physicians and Surgeons, and Director of Islet Transplantation at NewYork-Presbyterian Hospital/ Columbia University Medical Center.

In collaboration with Alan Goldstein, PhD, Dr. Hardy was the first to test new synthesized thymic hormones in 1968. Since then the hormones have been studied by several groups in adult patients with cancer, children with mucocutaneous candidiasis, and now in the healing of chronic wounds. "As a surgeon, I have had a long-term interest in finding ways of helping to speed up wound healing," says Dr. Hardy.

Although thymosin has not proven as successful in treating cancer as researchers had hoped, studies have found that it does improve the healing of chronic wounds. Initial tests on pressure sores in animal models found that thymosin is active in several wound healing processes, according to June K. Wu, MD, Assistant Professor of Clinical Surgery at Columbia University College of Physicians and Surgeons, and Co-Principal Investigator with Dr. Hardy. The next phase of the current study will be among the first to test thymosin beta-4 in people with pressure sores.

The thymosin beta-4 trial, sponsored by RegeneRx Biopharmaceuticals, Inc., is a randomized, double-blind, placebo-controlled study. About 20 patients will be enrolled at NewYork-Presbyterian/Columbia, and three-quarters of these will receive topical thymosin for their chronic wounds. The safety of three doses will be evaluated in this phase of study. NewYork-Presbyterian/Columbia is one among four participating institutions.

"Finding an agent that can promote healing of chronic wounds, reduce the time it takes for them to heal, or reduce the rate of recurrence of wounds, would have the potential to improve the lives of many disabled patients," says Dr. Hardy.

Based on the results of this phase of the trial, the investigators plan to expand the study to examine the effect of thymosin beta-4 on the rate of postoperative wound healing, and to study the mechanism of its activity. This could lead to the clinical application of this novel hormonal approach to the recovery of surgical patients whose wound healing is impaired by various diseases.