Spain-based Grifols has announced positive Phase 1 safety and tolerability results for plasmin in treating patients with blood clots in the lower extremities, known as acute peripheral arterial occlusion (aPAO).
Plasmin, a stabilised protein derived from human plasma, is a direct-acting thrombolytic which exerts its effects directly on the blood clot.
Grifols plasmin medical director, David Fineberg, said the desired clinical outcome is to quickly dissolve the clot while reducing the incidence and severity of bleeding complications that can occur with indirect thrombolytics.
"Our Phase 1 results represent an important milestone in the development of plasmin as we continue into Phase 2 efficacy trials," Fineberg added.
In the study, Grifols' plasmin was administered to treat 83 patients with treat recent-onset, arterial occlusions in native arteries or bypass grafts.
The subjects, who were enrolled in seven sequential dose cohorts that received between 25mg and 175mg of plasmin delivered locally via catheter, were monitored for 30 days for clinical outcomes and laboratory parameters of safety.
Nineteen patients reported one or more serious adverse events (SAE), major bleeding occurred in four patients and minor bleeding in 13 patients, with no trend towards more SAEs or bleeding episodes at higher doses of plasmin.
The data demonstrated that thrombolysis occurred in 79% of subjects receiving 125mg to 175mg of plasmin, compared with 50% who received 25mg to 100mg.
A multinational Phase 2 efficacy trial of Plasmin is currently in progress.