Skin substitute presents therapeutic option for venous leg ulcers

Key Points

South Miami, Fla. - Regardless of etiology, lower-extremity ulcers can be very challenging to treat, and patients may sometimes require more than the body's own natural healing abilities to close them.

Dermagraft (Advanced BioHealing) is a bioengineered skin substitute that helps achieve rapid closure of lower-extremity ulcers and, according to one expert, surpasses similar products on the market.

"Dermagraft is not meant to take like a skin graft, but instead works as a bio-delivery scaffold. The novel product is meant to deliver physiologically relevant amounts of proteins, growth factors and matrix to a wound that is having trouble creating those and can significantly assist in the rapid closure of ulcers," says Jason R. Hanft, D.P.M., F.A.C.F.A.S., of the Foot & Ankle Institute, South Miami, Fla.

Derived from human foreskin tissue, Dermagraft is a cryopreserved human fibroblast-derived dermal substitute composed of fibroblasts, extracellular matrix and a bioabsorbable scaffold. The fibroblasts proliferate to fill the interstices of this scaffold and secrete human dermal collagen, matrix proteins, growth factors and cytokines to create a three-dimensional human dermal substitute containing metabolically active, living cells.

The product has been available for more than 10 years. Dermagraft is undergoing an international, multicenter, prospective, controlled clinical study that includes more than 400 patients suffering from chronic venous leg ulcers. The research aims to assess the effect on healing chronic venous leg ulcers and confirm the product's safety and efficacy in this patient population.

Participants have been randomized to receive either weekly applications of Dermagraft and four-layer compression dressings or only weekly applications of four-layer compression dressings (control group). Patients are seen weekly until wound closure is achieved or until the 19-week treatment study is completed. Follow-up visits are to be done monthly for three months, assessing the products' safety and efficacy in venous leg ulcer closure.

Definite advantages

According to Dr. Hanft, one of the keys to successful wound therapy is the speed at which wound closure can be achieved. Dermagraft has definite advantages over other FDA-approved biologic products such as Apligraf (Organogenesis), he says, because for diabetic foot ulcers, Dermagraft is indicated weekly while Apligraf is indicated monthly.

"Wounds that are older than four weeks old have about an 80 percent chance of increased complications. Therefore, if you are not rapidly reducing the wound size, you will inevitably encounter more complications," Dr. Hanft says.

"Aside from the medical sequelae resulting from not achieving wound closure, there are also economic repercussions, and insurance (companies) need to understand the price of inaction by not covering the cost of Dermagraft treatment," he says.

Current guidelines

According to the FDA, the standard of care for venous leg ulcers is elevation of the leg and compression bandaging/moist wound healing. This approach, however, does not support new skin growth to fully close the wounds in all patients. Dermagraft represents a catalyst in the wound-healing process by promoting a healthy, viable ulcer bed for supporting and stimulating the growth of new tissue. Dr. Hanft says when compared to moist wound healing, Dermagraft heals wounds 64 percent faster in diabetic foot ulcers.

"If Dermagraft will show the same or similar positive results in venous leg ulcers as it already has with diabetic foot ulcers, this novel biologic therapy could change people's current mode of operation, and has the potential to become the future gold standard for these indications," Dr. Hanft says.

Disclosures: Dr. Hanft is a consultant for Advanced BioHealing and has performed the clinical trial for Dermagraft for the treatment of diabetic foot ulcers.