August 3, 2012
Cell-Based Therapy Helps Leg Ulcers Heal In The Form Of Spray-On Skin
Lawrence LeBlond for redOrbit.com - Your Universe Online
A topical spray containing a unique formula of living human cells developed and studied by US and Canadian researchers has been shown to provide a 52 percent greater chance of healing chronic venous leg ulcers than treatment with compression bandages alone. Findings of the study are published in the latest issue of the journal The Lancet.
Leg ulcers, painful open wounds that can last for months without proper treatment, are generally treated with the use of compression bandages, which only heal about 70 percent of ulcers after six months of use. Other options include taking skin from another area of the body and grafting it over the wound. The spray on the other hand, puts a coating of donated skin cells and blood-clotting proteins over the wound and has shown positive results.
Despite the potential cost of the new method, it could help people save money in the long run and offer faster healing, according to researchers.
The Phase II clinical trial investigated the efficacy of HP802-247 from US-based Healthpoint Biotherapeutics and was designed to determine effectiveness of certain cell concentrations and dosing frequencies of the product when combined with standard treatments of chronic venous leg ulcers.
Dubbed “spray-on skin,” HP802-247 was used on 228 people with leg ulcers. Patients who were treated with the spray every 14 days showed the most improvement. The size of the wound “began to decrease rapidly” as soon as the treatment started, and 70 percent of patients who were treated every two weeks completely healed within three months compared to only 46 percent of those who received traditional treatment.
Venous leg ulcers are caused by impaired circulation in the vein system of the legs due to blockages or other damage. Venous leg ulcers become chronic if the wound doesn´t heal after months of treatment. Chronic venous leg ulcers appear as open lesions. An estimated 1 to 2 million Americans suffer from venous leg ulcers.
HP802-247 consists of skin cells which release growth factors into the wound on a cellular level for tissue regeneration. The solution forms a “cellular web” for blood clotting and elasticity.
The researchers, led by William Marston, MD, professor of surgery at University of North Carolina School of Medicine and medical director of the Wound Healing Clinic, enrolled patients for the study at 28 medical centers in the US, including UNC. They used two different cell concentrations and two separate dosing frequencies over a 12-week period.
“In the past, some chronic venous leg ulcers were treated with skin grafts, which occasionally could break down and also required the patient to heal a partial thickness wound at the skin graft harvest site," said Marston. "During this study, unique living cells were sprayed on the patient's wound, which interacted with the patient's cells for improved wound healing.”
“The treatment we tested in this study has the potential to vastly improve recovery times and overall recovery from leg ulcers, without the need for a skin graft,” said study coauthor Dr. Herbert Slade, of Healthpoint. “This means not only that the patient doesn't acquire a new wound where the graft is taken from, but also that the spray-on solution can be available as soon as required - skin grafts take a certain amount of time to prepare, which exposes the patient to further discomfort and risk of infection.”
“A dressing or other application may have a positive effect on the wound for a period of time but ultimately if the underlying condition is not managed the leg will break down again,” Irene Anderson, a lecturer in leg ulcer theory at the University of Hertfordshire, told James Gallagher at BBC News.
“We do know that leg ulcers are becoming increasingly complex and when using the range of treatments available there needs to be clear evidence that there will be a beneficial effect to ensure cost effectiveness and to make sure that patients are not given false expectations of a cure,” she added.
While HP802-247 shows great potential for the treatment of venous leg ulcers, compression will remain the main form of treatment for some time, noted Professor Matthias Augustin from the University Medical Centre in Hamburg, Germany.
“We are currently preparing a Phase III pivotal trial to start late this year,” Marston concluded.