A method of adjunctive therapy to inhibit reocclusions in a patient, e.g., after thrombolytic therapy or angioplasty, by administering to the patient a bolus of an amount of purified pro-urokinase ("pro-UK") that inhibits the formation of occlusive thrombi without inducing a systemic effect in the patient, the pro-UK is administered after the completion of the thrombolytic treatment and periodically thereafter for the duration of therapy, and becomes incorporated into the outer membrane of the platelets of the patient, thereby increasing the T.sub. 1/2 of the pro-UK in plasma, which is about 7 to 8 minutes, to about 4 to 5 days, and inhibiting reocclusion without inducing a systemic effect.