MOBILE Evaluates Cell Therapy to Treat CLI in Patients With Severe PAD

September 19, 2016—Michael P. Murphy, MD, presented the MOBILE study during the first Late-Breaking Trials session at VIVA 16, the 14th annual Vascular InterVentional Advances meeting, which is sponsored by VIVA Physicians, Inc. and held September 18–22, 2016 at the Wynn Las Vegas in Las Vegas, Nevada.

The phase 3 MOBILE (MarrowStim Treatment of Limb Ischemia in Subjects With Severe Peripheral Arterial Disease) clinical trial is a prospective, double-blind, placebo-controlled, randomized, multicenter study that sought to determine whether autologous bone marrow–derived progenitor cells (MarrowStim, Zimmer Biomet) could decrease major amputation in patients with critical limb ischemia (CLI).

The primary endpoints were assessment of treatment-related adverse events and time to major amputation or all-cause mortality (amputation-free survival).

This is the first phase 3 trial in cell therapy for CLI to complete enrollment in the United States. It enrolled 152 patients (155 limbs treated) at 24 sites. The rationale and design of this trial was based on a previous phase 1 trial and used a 3:1 treatment-to-placebo randomization scheme; stratification of randomization was also based on Rutherford score and presence of diabetes.

As reported by Dr. Murphy at VIVA 16, the primary efficacy analysis showed a numerically smaller, but not statistically significant, event proportion for MarrowStim compared with placebo (20.17% vs 30.56%; P = .224). When the smallest subset of most challenging patients (prospectively defined strata of patients with both diabetes and tissue loss) were excluded from the analysis, there was a significant improvement in amputation-free survival (86.2% vs 66.7%; P = .018). Additionally, there was an excellent safety profile compared to the placebo with no statistically significant difference in adverse/serious adverse events between treatment arms.

Future studies are needed to better understand the mechanism of action of concentrated bone marrow aspirate and to further assess the potential benefits of the treatment in individual subgroups, advised Dr. Murphy at VIVA 16.