Cryopreserved Human Umbilical Cord (TTAX01) for Late Stage, Complex Non-healing Diabetic Foot Ulcers (AMBULATE DFU II)

This trial is designed as a confirmatory study of the benefits and risks of TTAX01 when used in the treatment of Wagner Grades 3 and 4 DFU. Experience with the use of a cryopreserved umbilical cord (UC) product in treating such wounds, both prior to this IND and under this IND, has indicated that a frequency of application of no shorter than every 4 weeks is associated with better than expected outcomes. Although treatment cannot be blinded, a "standard care only" arm is included to control for the benefits of aggressive baseline debridement combined with aggressive (6 weeks systemic) antibiotics. Current treatment guidelines indicate that aggressive debridement plus 1-2 weeks of antibiotics, or, minor debridement plus 6 weeks of antibiotics, would produce equivalent outcomes, although the evidence is not strong. By utilizing both maximum debridement and maximum antimicrobial therapy, the standard care described in this protocol may result in healing rates somewhat superior to current standard practice. The design of this second confirmatory study is matched to the design of the Phase 2 efficacy study TTCRNE-1501, with the exception of extending the primary endpoint from a landmark analysis at 16 to a "wound survival" analysis through 26 weeks, utilizing a proportional risk analysis rather than a simple test of proportions. This design consideration is based on analysis of previous studies (see Background section), and a desire to fold data from every visit into the primary analysis, rather than generating an excessive number of secondary endpoints.