Objective: To compare outcomes of diabetic foot ulcers (DFUs) treated with clostridial collagenase ointment (CCO) or silver-containing products, both in combination with sharp debridement as needed. Approach: One hundred two subjects with qualifying DFUs were randomized to daily treatment with either CCO or a silver-containing product for 6 weeks followed by a 4 -week follow-up period. The primary outcome was the mean percent reduction in DFU area. A secondary outcome was the incidence of ulcer infections between groups. Results: At the end of treatment, the mean percent reduction in area from baseline of DFUs treated with CCO was 62% (p < 0.0001) and with silver was 40% (p < 0.0001). The difference between groups-22%-was not statistically significant (p = 0.071). Among ulcers closed by the end of treatment, the mean time to closure was 31.1 ± 9.0 days versus 37.1 ± 7.7 days, respectively (not statistically significant). There was a numerically greater incidence of target ulcer infections in the silver group (11, 21.6%) than in the CCO group (5, 9.8%; p = 0.208). No clinically relevant safety signals were identified in either group. Innovation: CCO treatment can progress a wound toward closure. Ulcer infection prophylaxis may not be sacrificed when treating DFU with CCO in lieu of silver-containing products. Conclusion: Both CCO and silver-containing products promote significant reduction in DFU area over 6 weeks of treatment with no clinically relevant safety concerns. Mean percent reduction in lesion area was numerically (22%) but not significantly greater with CCO compared to silver, as was time to ulcer closure, with an incidence of ulcer infection at least as low as for silver-containing products.
Keywords: collagenase; debridement; diabetic foot ulcer; infection; silver; wound healing.