Stem cell therapy fails to improve symptoms of peripheral artery disease

A new study has revealed that a promising stem cell therapy failed to improve ability to walk in patients with peripheral artery disease (PAD), a condition that causes pain or weakness in the legs due to atherosclerotic blockages in the legs.

PAD is quite common in elderly patients, being present in up to 20% of those over 60. The study, conducted by a team at the Northwestern University Feinberg School of Medicine, investigated the efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF), a stem cell-based therapy designed to increase circulating stem cells in the blood, when combined with exercise or administered alone.

Sadly, after 12 weeks it was found that the treatment had not led to any desired improvements. The efforts represented an attempt to meet an unmet need in the disease area, as there are currently very few treatments which effectively prevent mobility loss in patients with PAD besides certain exercises which have been proven to improve walking ability.

"There is a lot of interest in stem cell therapy, and this is the largest trial of this type of therapy conducted to date in people with blockages in their leg arteries," remarked study leader Dr Mary McDermott. "It was disappointing that we did not see a benefit from this because so few therapies are available for patients with peripheral artery disease, and earlier research suggested this drug may be beneficial. More research is needed to identify new effective therapies."

Dr Diane Reid, a National Heart, Lung and Blood Institute (NHLBI) project officer for the study and a Medical Officer in the NHLBI Vascular Biology and Hypertension Branch, also commented: "Although this trial showed no added benefit of stem cell mobilization by GM-CSF in individuals with PAD, it yet again confirmed the benefits of exercise on walking capacity that have been observed in previous studies. Prompt reporting of negative clinical trial results, as done here, provides valuable information to guide the future directions of research on potential new therapeutics."