Granulocyte-Macrophage Stimulating Factor (GM-CSF) in Peripheral Arterial Disease: The GPAD-3 Study
Peripheral artery disease (PAD) is a disease in which plaque builds up in the arteries that carry blood to the head, organs, and limbs. PAD usually occurs in the arteries in the legs, but can affect any arteries. Over time, plaque can harden and narrow the arteries which limits the flow of oxygen-rich blood to organs and other parts of the body. Blocked blood flow to the arteries can cause pain and numbness. The pain is usually worse with exercise and gets better with rest. PAD can raise the risk of getting an infection which could lead to tissue death and amputation. This study is investigating whether granulocyte-macrophage colony stimulating factor (GM-CSF) improves symptoms and blood flow in people with PAD. GM-CSF is a drug that is used to stimulate the bone marrow to release stem cells. Participants in the study will be randomly selected to receive GM-CSF or a placebo. After a four-week screening phase, participants will receive injections of GM-CSF or a placebo three times a week for three-weeks. Three months later, participants will again receive injections of GM-CSF or placebo three times a week for three-weeks. At six months, the study team will follow up to see if the group that received GM-CSF had more improvement than the group that received placebo.
• Female subjects must be (a) post-menopausal, (b) surgically sterile or (c) use adequate birth control and have a negative pregnancy test within 3 days prior to administration of study drug and should not be breastfeeding.
• Documented symptomatic PAD
• Clinically stable (at least 2 months prior to enrollment) history of intermittent claudication or walking impairment (Rutherford Class II) with no change in symptom severity in the 2 months prior to screening.
• On statin therapy for previous 3 months prior to enrollment, unless statin intolerant.
• Peak Walking Time (PWT) between 1 and 12 minutes on a standardized Gardner treadmill protocol or modified Gardner protocol or less than 12 minutes on a modified Bruce protocol in case PWT on Gardner protocol is more than 12 minutes.
• A Doppler-derived ankle-brachial index (ABI) of \< 0.90 in the symptomatic limb after 10 minutes of rest at screening. For subjects with an ABI of \>1.3 (non-compressible arteries) a Toe-Brachial Index (TBI) of \< 0.70 must be obtained for subject qualification, or if ABI is \> 0.9 to 1.0 , and a reduction of 20% in ABI measured within 1 minute of treadmill testing.
• On appropriate and stable medical therapy for atherosclerosis for at least 2 months prior to enrollment.
• Able to give informed consent.
• Diabetics with a dilated eye exam excluding proliferative retinopathy in the previous 12 months prior to enrollment.