Animal experiment:

Compstatin-perfused circuit: pig xenografts are perfused with human blood containing Compstatin (final conc. 0.088 mg/mL). Control group: pig kidneys perfused with human blood and control agent. The total fluid volume, protein concentration and amount of blood are equal in both the Compstatin and control perfusion circuits, and the perfusion is performed in both circuits simultaneously with pooled blood from the same two donors.

Compstatin is a 13-residue cyclic peptide and a potent inhibitor of the complement system, and has species specificity.

Compstatin binds to baboon C3 and is resistant to proteolytic cleavage in baboon blood (similar to humans); Compstatin inhibits only the activation of primates' complement system[1].

Compstatin (21 mg/kg) produces complete inhibition when given as a combination of bolus injection and infusion. Compstatin completely inhibits in vivo heparin/protamine-induced complement activation without adverse effects on heart rate or systemic arterial, central venous, and pulmonary arterial pressures[1]. Pig xenografts survival is significantlylonger in the Compstatin perfused group than in the control group. At rejection the biopsy samples obtained from kidneysperfused with Compstatin show less deposition of C3 and fibrin than do the control kidneys[2].

References:
[1]. Soulika AM, et al. Inhibition of heparin/protamine complex-induced complement activation by Compstatin in baboons. Clin Immunol. 2000 Sep;96(3):212-21.
[2]. Fiane AE, et al. Compstatin, a peptide inhibitor of C3, prolongs survival of ex vivo perfused pig xenografts. Xenotransplantation. 1999 Feb;6(1):52-65.