Press Release: Eculizumab Phase 2 Clinical Trial didn't reach statistical signif

[Clark]

http://www.businesswire.com/news/home/20150107006360/en/Alexion-Update-Phase-2-Clinical-Trial-Eculizumab

Alexion Pharmaceuticals, Inc. (NASDAQ:ALXN) today reported results from its randomized, open-label, multicenter Phase 2 clinical trial to determine the safety and efficacy of eculizumab in the prevention of antibody mediated rejection (AMR) in living-donor kidney transplant recipients requiring desensitization. The primary composite endpoint, defined as the occurrence of biopsy-proven AMR, graft loss, patient death, or loss to follow-up at Week 9 post-transplant, did not reach statistical significance. While the primary composite endpoint rate in the eculizumab arm was as expected from earlier studies with eculizumab, the rate in the control arm was lower than was expected, based on natural history studies reported in the literature.

“Although eculizumab performed in line with the results reported from prior eculizumab studies, which showed similarly low AMR rates in high-risk patient populations, we are disappointed that this trial did not meet its primary composite endpoint,” said Martin Mackay, Ph.D., Executive Vice President and Global Head of R&D at Alexion. “We expect to complete the data analyses and discuss these results with regulators, and are currently developing plans to commence a clinical trial with eculizumab as a treatment for patients diagnosed with AMR.”

About the Clinical Trial

This Phase 2 trial enrolled 102 patients receiving kidney transplants from living donors, all of whom were at risk of AMR, based on elevated levels of donor-specific antibodies. After screening, patients were randomized into two groups of 51 patients each, with one group receiving eculizumab, and a control group receiving the anti-rejection standard of care specified by the institution in which each patient’s transplant took place. Patients in the standard of care control arm were eligible to receive eculizumab treatment for presumed AMR. Data were collected during the nine-week treatment period for the primary composite endpoint, with additional safety and efficacy endpoints measured through 12 months post-transplant. In the analysis of the 9-week data, for the primary composite endpoint, the rate was 9.8% in the eculizumab arm and 15.7% in the control arm (P=0.554). No safety signal has been reported to the Company by the independent data monitoring committee. Alexion expects that the data from the study will be presented at a future medical meeting.

About AMR

Acute antibody mediated rejection (AMR) is a severe and potentially life-threatening condition that can lead to severe allograft damage resulting in rapid loss of function and possible loss of the transplanted organ.1 Patients who are sensitized (have high levels of donor-specific-antibodies [DSAs]) are at high risk for developing acute AMR.1,2 The historical rate of AMR in high-risk living-donor kidney transplant recipients has been reported as high as 41%.3 Acute AMR is believed to be primarily a result of uncontrolled complement activation caused by DSAs.1,2 Currently, there are no approved therapies for the prevention or treatment of acute AMR.