Polyethylene glycol-derivatized cysteine-substitution variants of recombinant staphylokinase for single-bolus treatment of acute myocardial infarction

Circulation. 2000 Oct 10;102(15):1766-72. doi: 10.1161/01.cir.102.15.1766.

Abstract

Background: Thrombolytic therapy of acute myocardial infarction (AMI) is evolving toward bolus administration. Derivatization of proteins with polyethylene glycol (PEG) may reduce their clearance.

Methods and results: A staphylokinase (SakSTAR) variant with 12 amino acid substitutions to reduce its antigenicity, SakSTAR (K35A, E65Q, K74R, E80A, D82A, T90A, E99D, T101S, E108A, K109A, K130T, K135R), and with Ser in position 3 mutated into Cys (code SY161), was derivatized with maleimide-PEG with M:(r) of 5,000 (P5), 10,000 (P10), or 20,000 (P20). The PEGylated variants recognized only one third of the antibodies elicited with wild-type SakSTAR in AMI patients. In experimental animals, plasma clearances were reduced 2. 5- to 5-fold with P5, 5- to 20-fold with P10, and 20-fold with P20, and bolus injection induced pulmonary plasma clot lysis at doses inversely related to their clearance. Intravenous bolus injection of 5 mg of the P5, P10, or P20 variants in AMI patients was associated with plasma half-lives (t(1/2alpha)) of 13, 30, and 120 minutes and clearances of 75, 43, and 8 mL/min, respectively, compared with 3 minutes and 360 mL/min for SakSTAR. Injection of 5 mg P5 variant restored TIMI-3 flow within 60 minutes in 14 of 18 AMI patients (78%, 95% CI 55% to 91%) and of 2.5 mg in 7 of 11 patients (63%, 95% CI 35% to 85%), both in the absence of fibrinogen degradation. The immunogenicity of the variants was significantly (P:<0.002) reduced.

Conclusions: The staphylokinase variant SY161-P5, derivatized with one linear polyethylene glycol molecule of M:(r) 5000, is a promising fibrin-selective agent for single-bolus coronary thrombolysis.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Aged
  • Cysteine / chemistry
  • Enzyme Stability
  • Fibrinolytic Agents / immunology
  • Fibrinolytic Agents / pharmacokinetics
  • Fibrinolytic Agents / therapeutic use*
  • Half-Life
  • Humans
  • Metalloendopeptidases / chemistry
  • Metalloendopeptidases / immunology
  • Metalloendopeptidases / pharmacokinetics
  • Metalloendopeptidases / therapeutic use*
  • Myocardial Infarction / drug therapy*
  • Myocardial Infarction / metabolism
  • Polyethylene Glycols / chemistry
  • Recombinant Proteins / immunology
  • Recombinant Proteins / pharmacokinetics
  • Recombinant Proteins / therapeutic use

Substances

  • Fibrinolytic Agents
  • Recombinant Proteins
  • Polyethylene Glycols
  • Metalloendopeptidases
  • auR protein, Staphylococcus aureus
  • Cysteine