Patients with symptomatic peripheral artery disease who received therapy with granulocyte-macrophage colony-stimulating factor three times a week did not improve treadmill walking performance, according to recently published study results.
Between January 2010 and July 2012, 159 patients with peripheral artery disease (PAD) and intermittent claudication were enrolled at medical centers affiliated with Emory University in Atlanta, Ga. Researchers randomly assigned participants to receive 4 weeks of subcutaneous injections of granulocyte-macrophage colony-stimulating factor (GM-CSF), 500 µg per day three times a week or placebo. Both groups were encouraged to walk to claudication daily.
Primary outcome measures included peak treadmill walking time at 3 months. Secondary outcomes were peak treadmill walking at 6 months and changes in circulating progenitor cell levels, ankle brachial index and scores on both a walking impairment questionnaire and the Short-Form Health Survey (SF-36).
At 3 months, researchers found mean peak treadmill walking time increased in the GM-CSF group from 296 seconds to 405 seconds and from 308 seconds to 376 seconds in the placebo group. However, this difference was not significant. Between the groups, researchers found no significant differences in the ankle brachial index, walking impairment questionnaire distance and speed scores, claudication onset time or mental or physical component scores of the SF-36.
Study results showed GM-CSF improved the physical functioning subscore of the SF-36 questionnaire by 11.4 at 3 months compared with placebo, with a mean difference in change from GM-CSF vs. placebo of 7.5. The distance score of the walking impairment questionnaire also improved by 12.5 in patients receiving therapy vs. 4.8 in patients receiving placebo.
Although therapy with GM-CSF did not improve treadmill walking performance, “the improvement in a subset of secondary outcomes observed with GM-CSF suggests that GM-CSF may warrant further study in patients with claudication,” the researchers concluded.
For more information:
Poole J. JAMA.2013;doi:10.1001/jama.2013.282540.
Disclosure: Corresponding study author Arshed Quyyumi is a member of advisory boards for Amorcyte, Soteria and Stemedica and has received grants from Forest, Amgen, Genzyme and Stemedica. No other disclosures were reported.