In a multi-center double-blind cross-over study, the efficacy, safety and utility of RPY-005, a low molecular weight heparin, administered in a single bolus as an anticoagulant for hemodialysis were compared with those of the control, i.e. unfractionated heparin administered by continuous infusion in 148 patients undergoing hemodialysis for chronic renal insufficiency who had no hemorrhagic lesions or predisposition. The following results were obtained.

1) The patient characteristics and dialysis conditions were similar between the group receiving RPY-005 first and the group receiving the control heparin first.

2) There was no significant difference between the RPY-005 and heparin groups in body weight or blood pressure before or after hemodialysis during the course of the study.

3) On most occasions of hemodialysis, residual blood and clot in extracorporeal circulation were not observed, or slight if any. There was no significant difference between the RPY-005 and heparin groups in the intra-circuit pressure or hemodialysis efficiency as well as in residual blood and clot in extracorporeal circulation.

4) The hemostasis time after removal of the needle inserted into the blood access showed no significant changes during the course of the study and did not differ significantly between the RPY-005 and heparin groups.

5) RPY-005 caused a significantly smaller change in the whole blood clotting time than the control heparin did.

6) There was no difference in change in serum lipid levels between the RPY-005 and heparin groups.

7) As adverse reactions, subcutaneous hemorrhage occured in one patient during the treatment with RPY- 005, and discomfort, facial flush and hypotension in one patient during the treatment with the control heparin. All symptoms were moderate.

8) There were no treatment-related abnormal laboratory findings during the course of the study.

9) The attending physicians and the organizing committee made similar ratings in evaluation of the efficacy, safety and utility for the treatments.

10) In the comparison between overall assessments of the two agents, both the attending physicians and the organizing committee judged RPY-005 as being significantly superior over the control heparin as an anticoagulant for hemodialysis.

11) The clinical evaluations made by the attending physicians and the committee were not affected by treatment order. Based on these results, it was concluded that RPY-005, administered as a single dose at the start of dialysis, was a more useful anticoagulant than the control heparin administered by continuous infusion.