PDL BioPharma, Inc., a biopharmaceutical company focused on discovering, developing and commercializing innovative therapies for severe or life- threatening illnesses, has announced that a double-blind, placebo-controlled, phase 3 clinical study of terlipressin, a vasoactive peptide, did not meet its primary endpoint in the treatment of type 1 hepatorenal syndrome (HRS), a life-threatening complication of advanced liver disease characterized by rapidly progressive kidney failure.

In this study, the primary endpoint was treatment success, defined as the percentage of patients alive at Day 14 who demonstrated reversal of type 1 HRS, based upon two measurements of serum creatinine levels less than or equal to 1.5 mg/dL without dialysis or recurrence of disease. The data showed a positive trend towards the treatment success, but did not reach statistical significance.

"We are disappointed that the trial of terlipressin did not meet its primary endpoint, as there is a substantial unmet need in HRS," said Steven Benner, M.D., Chief Medical Officer, and PDL. "We will work with Orphan Therapeutics to further analyze the study results."

PDL obtained US commercial rights to terlipressin following its acquisition of ESP Pharma in March 2005. The original agreement between ESP Pharma and Orphan Therapeutics was established in June 2004.

Peter Teuber, Ph.D., President of privately-held Orphan Therapeutics, said, "We applaud the investigator community for their support and participation in this important clinical trial for a disease, which has a serious unmet medical need. Although the primary endpoint showed only a trend towards improvement, I am encouraged by other results and look forward to reviewing the data with the FDA."

This phase 3 study, conducted by Orphan Therapeutics, was the first randomized, double-blind, placebo-controlled clinical trial of terlipressin in type 1 HRS in the US. The study, which evaluated the safety and the potential effect of terlipressin on kidney function and survival in patients with type 1 HRS, enrolled 112 patients at 30 liver disease centres in the US and five centres outside the US. Patients were randomized to receive terlipressin or placebo every six hours until a reversal of HRS was seen or for up to 14 days.