Formulated collagen gel accelerates healing rate immediately after application in patients with diabetic neuropathic foot ulcers.

We assessed the safety and efficacy of Formulated Collagen Gel (FCG) alone and with Ad5PDGF-B (GAM501) compared with Standard of Care (SOC) in patients with 1.5-10.0 cm(2) chronic diabetic neuropathic foot ulcers that healed <30% during Run-in. Wound size was assessed by planimetry of acetate tracings and photographs in 124 patients. Comparison of data sets revealed that acetate tracings frequently overestimated areas at some sites. For per-protocol analysis, 113 patients qualified using acetate tracings but only 82 qualified using photographs. Prior animal studies suggested that collagen alone would have little effect on healing and would serve as a negative control. Surprisingly trends for increased incidence of complete closure were observed for both GAM501 (41%) and FCG (45%) vs. Standard of Care (31%). By photographic data, Standard of Care had no significant effect on change in wound radius (mm/week) from during Run-in to Week 1 (-0.06 ± 0.32 to 0.78 ± 1.53, p=ns) but both FCG (-0.08 ± 0.61 to 1.97 ± 1.77, p<0.002) and GAM501 (-0.02 ± 0.58 to 1.46 ± 1.37, p<0.002) significantly increased healing rates that gradually declined over subsequent weeks. Both GAM501 and FCG appeared to be safe and well tolerated, and alternate dosing schedules hold promise to improve overall complete wound closure in adequately powered trials.

Treatment of nonhealing diabetic foot ulcers with a platelet-derived growth factor gene-activated matrix (GAM501): results of a phase 1/2 trial.

The results from a Phase 1/2 study of a replication-defective adenovirus encoding human platelet-derived growth factor (PDGF)-B formulated in a bovine collagen (Ad-5PDGF-B; 2.6% collagen; GAM501) gel for nonhealing neuropathic diabetic foot ulcers is reported. The primary objectives of the study were to evaluate the safety, maximum-tolerated dose, and preliminary biological activity of GAM501. Fifteen patients enrolled into the study with chronic, nonhealing ulcers received either a single administration of GAM501 at one of three dose levels, or up to four administrations of GAM501 at 1-week intervals. All patients received standard of care treatment including debridement and were required to wear an off-loading shoe. GAM501 was found to be safe and well tolerated with no evidence of systemic or local toxicity at all doses so no maximum-tolerated dose was reached. Serum antibody titers to platelet-derived growth factor-B homodimer and collagen were negative and adenoviral DNA was not detected in the blood. In the 12 patients that completed the study, ulcer closure was observed by Month 3 in 10 patients, seven of whom received a single application of GAM501. In conclusion, GAM501 did not appear to have any toxicity at doses that showed biological activity. GAM501 holds promise as a potentially effective treatment for nonhealing diabetic foot ulcers.