Massive Pulmonary Embolism: Trial of Non-immunogenic Recombinant Staphylokinase VS Alteplase FORPE

The main goal of treating massive PE is to save the lives of patients by restoring pulmonary perfusion, preventing the development of chronic postembolic pulmonary hypertension and recurrent PE. According to data of clinical trials, with timely initiation of therapy for massive pulmonary embolism, mortality can be significantly reduced.

Recombinant protein which contains aminoacid sequence of staphylokinase - Fortelizin® (the active substance is Forteplase). It is single chain molecula, consists of 138 aminoacids, weight 15.5 kDa. When staphylokinase is added to human plasma containing a fibrin clot, it preferentially reacts with plasmin at the clot surface, forming a plasmin-staphylokinase complex. This complex activates plasminogen trapped in the thrombus. The plasmin-staphylokinase complex and plasmin bound to fibrin are protected from inhibition by alpha2-antiplasmin. Once liberated from the clot (or generated in plasma), however, they are rapidly inhibited by alpha2-antiplasmin. This selectivity of action confines the process of plasminogen activation to the thrombus, preventing excessive plasmin generation, alpha2-antiplasmin depletion, and fibrinogen degradation in plasma. In rabbits anti forteplase antibodies are not produced. It was achieved by replacement of amino acids in immunogenic epitop of molecule staphylokinase. Blood fibrinogen decrease after i.v. injection of Fortelyzin less 10% within first 24 hours. Angiographic data suggests that restoration of coronary blood flow appears in up to 80% of patients with STEMI after i.v. injection of Fortelyzin.

The main objectives of the study: to assess the efficacy, safety and possible adverse events of the drug Recombinant Non-immunogenic Staphylokinase with its single bolus administration in comparison with the bolus-infusion administration of the drug Alteplase® in patients with massive pulmonary embolism.

Study Design. Multicenter, open-label, randomized, comparative clinical study of non-inferiority study of efficacy and safety in parallel groups. At clinical centers, patients will be equally randomly distributed by the "envelope" method into two groups of 155 patients each (310 people in total, including 10% of those who may have dropped out)to receive Recombinant Non-immunogenic Staphylokinase or Alteplase®.

The drugs will be administered after the signed informed consent. Recombinant Non-immunogenic Staphylokinase will be administered intravenously at a dose of 15 mg as a single bolus for 10-15 seconds. Alteplase® will be administered in accordance with the instructions for use.

Patients will be monitored for 30 days from the moment of randomization: in the intensive care unit up to 7 days, after it in the hospital until discharge - an average of 14 days and an outpatient visits on the 30th day. The recruitment of patients for the study will be competitive.