The Pharmaceutical Journal Vol 263 No 7063 p411
September 18, 1999 Clinical

Growth factor gel for treating diabetic ulcers

A new type of product for treating chronic diabetic ulcers has been launched this week. Regranex gel, from Janssen-Cilag, contains a growth factor to promote wound healing.
The active agent is called becaplermin, and is a recombinant human platelet-derived growth factor (PDGF), one of the growth factors involved in normal healing processes. The gel is licensed for use in patients with full thickness, neuropathic, chronic diabetic ulcers (see p465).
Dr Robert Donnelly (medical director, Janssen-Cilag) said on September 13 that diabetic ulcers, the majority of which were on the sole of the foot or around the ankle, were notoriously difficult to heal but that application of "pharmacological PDGF" to the wound surface could accelerate healing. "It heals more ulcers [than standard treatment] and heals them more quickly," he said.
A US clinical trial with the product involved 382 patients with chronic ulcers of at least eight weeks' duration. Use of the gel, in conjunction with good wound care, was associated with a 43 per cent increase in the incidence of complete wound closure (50 per cent of patients versus 35 per cent with placebo gel). There was also a 32 per cent decrease in time to complete wound closure (86 versus 127 days). The safety profile was reported to be similar to that of placebo gel (Diabetes Care 1998;21:822). The gel is applied daily. Janssen-Cilag says that treatment can be applied in outpatient clinics or, after instruction, at home by the patient or a carer.
Regranex costs £275 per tube. Dr Donnelly said that two tubes would probably be needed to heal an average ulcer. He suggested that quicker healing, with consequent reduction in outpatient attendances for treatment, would "more than compensate for the acquisition costs." The company also hoped that, by increasing ulcer healing, the new treatment might reduce the need for lower limb amputations, which could be the outcome in infected diabetic ulcers.

Speaking to The Journal on September 15, Dr Michael Edmonds (consultant diabetologist, King's College hospital, London) said that diabetic foot ulcers were a major public health problem. Some patients had ulcers that did not respond to standard care; it appeared that some aspects of wound healing were impaired in diabetes. PDGF was the first growth factor to have shown clinically significant results in wound healing studies, he said. It acted in all phases of wound healing and enhanced the formation of granulation tissue. Other growth factors were being investigated and Dr Edmonds said that it might eventually be possible to use different factors for different phases of the wound healing process. Human PDGF consists of two linked polypeptide chains, A and B, and exists naturally as AA, BB or AB. Becaplermin is PDGF-BB. Janssen-Cilag says that this is the form responsible for promoting formation of granulation tissue. Becaplermin is made by inserting the gene for the B chain into cultured yeast cells. These cells produce PDGF-B, and single PDGF-B chains are then combined to form PDGF-BB.

Diabetic foot ulcers "a major public health problem"

Regranex is now being evaluated for treatment of venous ulcers and pressure ulcers.
Another treatment for chronic diabetic ulcers is Smith & Nephew's Dermagraft, a bioengineered human skin replacement, which was launched in 1997. This product is more expensive than the PGDF gel.