Alexion announces results of eculizumab two open-label Phase 2 studies for aHUS treatment

Alexion Pharmaceuticals, Inc. (Nasdaq: ALXN) today announced that its two open-label Phase 2 studies investigating eculizumab (Soliris^®) as a treatment for patients with atypical Hemolytic Uremic Syndrome (aHUS) have met the primary and key secondary endpoints with high clinical and statistical significance, in interim analyses. aHUS is an ultra-rare, chronic and life-threatening disease in which uncontrolled complement activation causes blood clots in small blood vessels (thrombotic microangiopathy, or TMA) throughout the body leading to stroke, heart attack, kidney failure and death. Approximately 60 percent of patients with aHUS require dialysis, a kidney transplant or die within a year of diagnosis. Abstracts summarizing these interim data have been posted on the web site of the American Society of Nephrology (ASN) at http://www.abstracts2view.com/asn. These two trials are currently ongoing and data will be presented at the ASN annual meeting held November 18 - 21 in Denver, Colorado.

“Safety and Efficacy of Eculizumab in aHUS Patients on Chronic Plasma Therapy: Interim Analysis of a Phase II Trial”

Patients Resistant to Plasma Therapy

Abstract 1338, "Safety and Efficacy of Eculizumab in aHUS Patients Resistant to Plasma Therapy: Interim Analysis from a Phase 2 Trial," summarized an interim analysis of 17 adolescent and adult patients with aHUS who were resistant to plasma therapy and were treated with eculizumab for up to 26 weeks. The primary endpoint of the study is the change in platelet count, a measure of TMA. In this interim analysis, researchers observed a significant 80 ± 64 x 10^3/uL (p<0.0001) increase in platelet count with eculizumab treatment compared to baseline. Key secondary clinical endpoints were also positive. Updated data from this study will be presented at the ASN annual meeting on Saturday, November 20 at 5:30 p.m. Mountain Standard Time (MST).

Patients on Chronic Plasma Therapy

Abstract #157, "Safety and Efficacy of Eculizumab in aHUS Patients on Chronic Plasma Therapy: Interim Analysis of a Phase 2 Trial," summarized interim results from a study of 20 adolescent and adult patients with aHUS who were receiving plasma therapy chronically prior to entering the study. The primary endpoint of the study is TMA Event-Free Status, as defined by stable platelet counts, absence of plasma therapy and no new dialysis. In this interim analysis of 15 patients treated with eculizumab for at least 12 weeks, a significant 87% (95% CI 60-98) of patients achieved TMA Event-Free Status. Key secondary clinical endpoints were also positive. Interim data from this study will be presented in a poster session at the ASN annual meeting on Friday, November 19 at 10:00 a.m. MST.

In both studies, interim results were reported at the last captured timepoint. Eculizumab appeared to be well-tolerated in the studies, with the most common adverse events including anemia, diarrhea, headache, nausea and hypertension.