Rationale and Design of Therapeutic Angiogenesis by Cell Transplantation Using Adipose-Derived Regenerative Cells in Patients With Critical Limb Ischemia　― TACT-ADRC Multicenter Trial ―

Background: Despite the growing knowledge regarding optimal treatments for critical limb ischemia (CLI), there are still a considerable number of patients who have to undergo major limb amputation. Intramuscular injection of autologous adipose-derived regenerative cells (ADRCs) in these patients has shown therapeutic potential in improving tissue ischemia, in both preclinical and initial pilot studies. Here, we present a clinical protocol for ADRCs use in a multicenter trial. Methods and Results: The TACT-ADRC multicenter trial is a prospective, interventional, single-arm, open-labeled study at 8 hospitals in Japan, investigating the safety and feasibility of intramuscular injections of ADRCs and testing the hypothesis that this treatment promotes neovascularization and improves major amputation-free survival rates in patients with CLI who have no other treatment option. 40 patients with CLI will be enrolled and followed up from November 2015 to November 2020. Freshly isolated autologous ADRCs will be injected into the target ischemic limbs. Survival rate, adverse events, major limb amputation, ulcer size, 6-min walking distance, numerical rating scale, ankle–brachial pressure index, skin perfusion pressure and digital subtraction angiography will be evaluated at baseline and during 6 months’ follow-up. Conclusions: This trial will demonstrate whether implantation of autologous ADRCs is a safe and effective method for therapeutic angiogenesis, resulting in an improvement in major amputation-free survival rates in patients with CLI.