San Diego's Mast Therapeutics Inc. (NYSE: MSTX) has initiated a phase 2, clinical proof-of-concept study of MST-188 in combination with recombinant tissue plasminogen activator (rt-PA) in patients with acute lower limb ischemia (ALI).
ALI, an acute complication of peripheral arterial disease, describes a sudden decrease in perfusion of a limb, typically in the legs, that often threatens viability of the limb. Patients presenting with ALI have a poor short-term outlook, with 30-day amputation rates as high as 30 percent and a mortality rate around 15 percent. MST-188 for the treatment of ALI has been granted orphan drug designation by the U.S. Food and Drug Administration.
"Numerous experimental models, as well as clinical studies, demonstrate that MST-188 facilitates thrombolysis, repairs damaged cell membranes, and improves microvascular blood flow," Martin Emanuele, Ph.D., senior vice president of development, said. "When combined with rt-PA, we believe these activities will translate into faster thrombolysis in patients with ALI and in other acute thrombotic events such as stroke, while at the same time reducing vessel re-occlusion, reperfusion injury, and tissue necrosis."
The study will enroll approximately 60 patients from approximately 15 sites within and outside the U.S. with Rutherford Category IIa and IIb acute lower limb ischemia receiving catheter-directed rt-PA and compare a high and low dose of MST-188 against rt-PA alone. The primary objectives are to evaluate the safety and efficacy of MST-188 in combination with rt-PA and whether MST-188 results in more rapid thrombolysis and tissue perfusion. Secondary objectives are to assess the clinically-meaningful benefit of MST-188 in combination with rt-PA by measures such as duration of thrombolytic therapy, amputation-free survival, target limb re-interventions, and the need for endovascular or open surgical re-interventions. These objectives will be measured through up to 90 days of follow-up. The study is expected to take approximately 18 months to enroll.
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