Abstract 8547: Patient-Specific Cellular Therapy (Ixmyelocel-T) is Safe and Improves Time to Treatment Failure in Patients with Critical Limb Ischemia and No Revascularization Options

Abstract

Background: Critical limb ischemia (CLI) represents the most severe degree of peripheral arterial disease and is associated with significant morbidity and mortality. Cellular therapy offers the potential to promote tissue remodeling, immuno-modulation, and angiogenesis. This Phase 2 study assessed the safety and efficacy of patient-specific, expanded bone marrow cells (ixmyelocel-T) in a no-option CLI population followed for 12 months. Methods: This randomized (2:1), double-blind, placebo-controlled, multicenter study compared one-time treatment of ixmyelocel-T with placebo, administered via 20 IM lower extremity injections. Bone marrow aspirates from patients in the ixmyelocel-T group were processed over 12 days to generate ixmyelocel-T mixed cell product. The primary objective was safety. A composite treatment failure efficacy endpoint (major amputation on treated limb, death, doubling of wound size from baseline, or de novo gangrene) and amputation-free survival (major amputation or death) were also evaluated. Results: Of the 72 patients who received injections (mean age 69 years, 67% male, 50% diabetic, 84% current or past smokers, 63% with baseline wounds), 48 received ixmyelocel-T and 24 placebo. No major safety concerns were evident (Table 1). The time to first occurrence of treatment failure was significantly longer in ixmyelocel-T-treated patients compared with placebo-treated patients (Figure 1, logrank test, p = 0.0032). Amputation-free survival showed a clinically meaningful 32% reduction in event rate but did not reach statistical significance (p = 0.3880). Conclusions: Ixmyelocel-T was safe and increased time to treatment failure.