The objectives of this study are to evaluate the safety and efficacy of NL in patients with IC. The primary efficacy analysis will be the percent change from baseline in Peak Walking Time (PWT) calculated from the natural logarithm of the ratio of the time walked on treadmill at the Week 32 Visit divided by the time walked at baseline. Other efficacy measures will include Claudication Onset Time (COT) percent changes from baseline to Week 32 , changes in Ankle Brachial Index (ABI), Quality of Life (QoL) percent changes at Weeks 20 and 32, lower limb amputations, composite of cardiovascular events (MI, stroke, and vascular death), and coronary and peripheral artery revascularizations. Safety variables will include serum transaminases, routine chemistry parameters, hematology, and adverse events. Pharmacokinetic analyses will be conducted as well.