Results from a phase 2 clinical trial suggest a multicellular therapy for the treatment of critical limb ischemia in patients with no revascularization options reduces the risk of disease progression in those patients.
The results were presented by William Marston, MD, chief, division of vascular surgery, and professor, department of surgery, University of North Carolina, at the 2011 American Heart Association Scientific Sessions in Orlando, FL.
The RESTORE-CLI phase 2 randomized, double-blind, placebo-controlled, multicenter study assessed the safety and efficacy of ixmyelocel-T, a patient-specific, expanded multicellular therapy for the treatment of CLI, in a group of 72 patients at 1 year after treatment. Patients in the treatment arm showed a 62% reduction in risk relative to placebo in the primary efficacy endpoint of time to first occurrence of treatment failure (p = .0032).
Treatment failure was defined as the first occurrence of any one of the following: major amputation of the treated leg, all-cause mortality, doubling of wound total surface area from baseline, or de novo gangrene. Although the study was not powered to show statistical significance in the secondary endpoint of amputation-free survival (AFS; major amputation of the treated leg or all-cause mortality), results from a subgroup of 45 patients with wounds at baseline showed a positive trend in this measure (21% in the ixmyelocel-T treated group vs. 44% in the control group). The study also met the primary safety endpoint with no differences between the treated and control groups.
“These results provide substantial additional evidence that treatment with ixmyelocel-T significantly reduces the risk of disease progression for CLI patients with no options for revascularization. Importantly, the efficacy results demonstrate concordance across all of the defined measures of treatment failure in the trial,” Dr. Marston stated in a press release. “In addition, the results related to AFS in the subgroup of patients with tissue loss similar to those who will be studied in the upcoming phase 3 clinical trial show a strong and clinically relevant positive trend for such a small number of patients. These results are especially encouraging since the primary endpoint for the planned REVIVE-CLI pivotal phase 3 clinical trial for ixmyelocel-T in no-option CLI patients will be amputation-free survival.”
Aastrom Biosciences, Inc. will initiate the REVIVE-CLI phase 3 clinical trial for ixmyelocel-T this quarter. The study will include 594 CLI patients with no option for revascularization and existing tissue loss. The primary endpoint of this study will be amputation-free survival at 12 months. Patients will be followed for a total of 18 months from the time of treatment.