Phase I/II Study Results Published for Aldagen's Stem Cell Therapy to Treat CLI

May 19, 2011—Aldagen, Inc. (Durham, NC) announced the publication of results from a phase I/II, multicenter, randomized, controlled clinical trial of autologous therapy with bone marrow–derived aldehyde dehydrogenase bright (ALDH[br]) cells in patients with critical limb ischemia (CLI). Emerson C. Perin, MD, et al published the findings online ahead of print in Catheterization and Cardiovascular Interventions.

According to the company, Aldagen's ALD-301 is a stem cell therapy that is being developed as a treatment for CLI. The double-blind study included a total of 21 patients who were randomly selected to receive an injection of either ALD-301 or unsorted cells from their own bone marrow (autologous bone marrow mononuclear cells). ALD-301 is the population of ALDH(br) stem cells produced using Aldagen's technology to sort a specified quantity of bone marrow collected from the patient receiving the therapy. These adult stem cells express high levels of the enzyme ALDH, which plays an important role in controlling the developmental state of stem and progenitor cells. ALD-301 is injected directly into the patient's leg muscle. The company noted that preclinical research suggests that ALDH(br) cells derived from bone marrow may promote the repair of ischemic tissue damage.

The primary objective of the trial was to evaluate the safety of ALD-301. Secondary endpoints of the trial included change in clinical status from baseline to 12 weeks, as measured by the Rutherford scale. In addition, change in blood flow to the leg was measured by ankle-brachial index and transcutaneous partial pressure of oxygen.

As detailed in Catheterization and Cardiovascular Interventions, ALD-301 was shown to be well tolerated, with no therapy-related serious adverse events. Patients who were treated with ALD-301 showed significant improvement in three efficacy endpoints (Rutherford category, ankle-brachial index, and quality of life [as measured by VascuQOL]) at 12 weeks compared to baseline. Additionally, patients who were treated with ALD-301 showed a significant decrease in rest pain at 6 weeks compared to baseline.

The company stated that the positive safety and efficacy data support the continued development of ALD-301, and Aldagen plans to initiate a 150-patient phase II trial. The planned phase II trial is a double-blind, placebo-controlled trial designed to assess the ability of ALD-301 to improve clinical outcomes in patients with CLI. The trial will allow Aldagen to determine the number of patients that will be required to show a statistically significant effect on a primary endpoint of 6-month amputation-free survival in a subsequent pivotal phase III study.