Protein Design Labs Inc. (PDLI) and partner Hoffmann-La Roche late on Friday announced that a Phase II/III trial of PDLI's Zenapax humanized Anti-Tac antibody failed to reduce the incidence of graft-versus-host disease (GvHD) in a Phase II/III trial of the compound's ability to prevent the disease in 210 patients.

Patients received doses of 0.3 or 1.2 mg/kg or placebo in the three-arm trial. All patients received standard GvHD immunosuppressant therapy of cyclosporine and methotrexate, and treated patients received Zenapax once a week for five weeks.