ViroPharma has initiated a Phase II clinical study to evaluate Cinryze, a C1 esterase inhibitor, for the treatment of acute antibody-mediated rejection in donor-specific, cross-match positive kidney transplant recipients.

The randomised, double-blind and placebo-controlled study will be conducted at four transplant centres in the US, and will evaluate the safety, tolerability and clinical effect of the drug.

Twenty subjects will be enrolled and randomised to receive either Cinryze or a placebo.

Subjects will be evaluated after eight weeks of treatment for pharmacokinetics, pharmacodynamics and clinical effect, and again at six months post-transplantation for graft function and patient survival.

Antibody-mediated rejection is a type of organ transplant rejection that occurs when a patient has antibodies circulating in their blood against the donor organ.

Cinryze is a plasma-derived C1 esterase inhibitor product that has been approved by the US Food and Drug Administration for routine prophylaxis against angiooedema attacks in adolescent and adult patients with hereditary angiooedema.