becaplermin

Becaplermin is a gel applied topically to diabetic ulcers on the lower limbs (foot, ankle, and leg) to promote healing of the ulcers. It belongs to a class of man-made drugs called platelet-derived growth factors or PDGFs that are similar to naturally-occurring PDGFs. Becaplermin is made using recombinant DNA technology. Becaplermin, or as it also is known, recombinant human PDGF (rhPDGF-BB), is active early in the process of ulcer healing. Wound and ulcer healing is a three-phased process that the body initiates after an injury to the skin. The process begins with the first phase, inflammation. In this phase, blood flow and fluid increase around the site of the ulcer. If there is bleeding from injured blood vessels, platelets from the blood invade the site of the ulcer and cause the blood to clot. This stops the bleeding. Platelets also release chemical messengers (proteins) called platelet- derived growth factors (PDGFs). These PDGFs send signals to cells around the ulcer and recruit them to the site of the ulcer where they initiate the second phase of the healing process, called proliferation. In this phase tissue is repaired and, if the injury is deep enough, scar tissue forms. The remaining cells of the normal skin divide and produce new cells to replace the damaged cells.

Diabetic ulcers heal slowly and sometimes not at all because the healing process is impaired, probably because blood flow to the skin is reduced in people with diabetes. This can lead to serious bacterial infections within the ulcers which can spread and necessitate amputation of the foot or leg. Becaplermin acts along with naturally- occurring PDGF to expedite the recruitment of cells to the ulcer, promote the division of cells and the formation of new skin. Remodeling, the third and final phase of wound healing, restructures the healed ulcer, and the scar tissue that has formed is broken down. As a result of remodeling, the new skin assumes the appearance of the old skin. Becaplermin is the first drug that can be applied directly to the ulcer that is designed to promote healing. It was approved by the FDA in December 1997.

Regranex

GENERIC AVAILABLE: No

Yes

AND PRECAUTIONS The most common side effect of becaplermin is a rash that can develop on the skin where it is applied. Other important side effects caused by the drug include redness of the skin called erythema, a skin ulcer with possible infection and pain at the location where the drug is applied. An increased risk of developing cancer or dying from cancer has been reported with becaplermin use. The drug should be used with caution in individuals with a history of cancer.

The amount of becaplermin that is applied to the ulcer depends on the size of the ulcer. This can be calculated by measuring the greatest length and width of the ulcer and then applying the amount that is recommended by the directions that accompany each tube of becaplermin. The following method is recommended depending on whether the measurements are in inches or centimeters as follows:

• A 15 g tube length of ulcer x width x 0.6 = length of gel (inches) or length of ulcer x width ÷ 4 = length of gel (cm)
• A 2 g tube length of ulcer x width x 1.3 = length of gel (inches) or length of ulcer x width ÷ 2 = length of gel (cm)