Separate Analysis of Patients with PNH and Thrombocytopenia Found Sustained Platelet Recovery Following Treatment with Soliris

Clinical investigators observed that Soliris^® (eculizumab), a first-in-class terminal complement inhibitor developed by Alexion Pharmaceuticals, Inc. (Nasdaq: ALXN), reduced hemolysis (red blood cell destruction) and improved symptoms in nine patients with paroxysmal nocturnal hemoglobinuria (PNH) who had received no blood transfusions prior to initiating Soliris therapy.

In a separate study of 11 patients with PNH, researchers observed sustained platelet recovery with Soliris treatment in a subset of seven patients with thrombocytopenia (reduced platelet levels), indicating a likely reversal of platelet consumption with Soliris in these thrombocytopenic PNH patients. These and other data sets were presented on June 6 and 7 at the European Hematology Association Congress in Berlin. Soliris is the only therapy approved in the European Union, United States, Australia and Canada for the treatment of patients with PNH, an ultra-rare, debilitating, and life-threatening blood disorder.

“All patients with PNH, including those who do not require transfusion and may appear to be stable, are at increased risk for blood clots, kidney dysfunction, pulmonary hypertension and disabling fatigue caused by hemolysis,” noted Leonard Bell, M.D., Chief Executive Officer of Alexion. “Research presented at EHA is a sobering reminder of the clinical consequences of this progressive, ultra-rare disease. These data further underscore the clinical impact of Soliris for the treatment of patients with PNH, and also provide insight into the potential role of complement inhibition in addressing other complement-mediated diseases.”

Never-Transfused and Minimally Transfused Patients with PNH

Abstract 0581 titled “Efficacy of the Complement Inhibitor Eculizumab in Paroxysmal Nocturnal Hemoglobinuria Patients Never Transfused,” was presented at a poster session at the EHA Congress on Saturday, June 6 by Dr. Antonio Risitano, Research Associate at the University of Naples in Italy.

Published research shows that Soliris reduces hemolysis in patients with PNH who require minimal transfusions. (1) However, many patients with PNH do not receive blood transfusions and continue to experience hemolysis and its clinical consequences. In this analysis, investigators assessed the safety and efficacy of Soliris in the treatment of nine patients with PNH who required no transfusions prior to starting Soliris therapy. These “never-transfused” patients were enrolled in the Italian Early Access Program with at least one of the following conditions: severe anemia due to intravascular hemolysis; frequent paroxysmal crises; severe symptoms due to hemolysis; or thrombosis (life-threatening blood clots).

All patients experienced a dramatic reduction in hemolysis following treatment with Soliris for a median of 16 months, as measured by a median reduction in LDH from 1,500 U/L before treatment to 356 U/L after treatment (p=0.008). Overall, hemoglobin levels increased significantly from 9.0 g/dL before treatment to 10.7 g/dL after treatment (p=0.0003), with a median increase of 2.0 g/dL. The investigator noted that patients reported a marked improvement in quality of life. No serious adverse events were reported.

Investigators compared these results to a subset of 21 patients previously enrolled in eculizumab clinical trials who had received zero or one transfusion during the year prior to eculizumab treatment. These patients experienced a significant reduction in hemolysis following six months of Soliris therapy, with a median reduction in LDH from 2,030 U/L before treatment to 336 U/L after treatment (p < 0.001). Hemoglobin levels increased significantly from 9.0 g/dL before treatment to 10.7 g/dL after treatment (p=0.0003), with a median increase of 1.7 g/dL. Fatigue was also significantly improved (p<0.001).

“PNH is a debilitating and life-threatening disease, even among patients who do not require blood transfusion,” noted Dr. Risitano. “Based on clinical data, eculizumab therapy inhibited hemolysis in these never-transfused patients, leading to immediate clinical benefit and potentially reducing the long-term morbidity and mortality associated with this ultra-rare disease.”

Patients with PNH and Thrombocytopenia

Abstract 0584 titled “Effect of Eculizumab Therapy on Thrombocytopenia in Patients with Paroxysmal Nocturnal Hemoglobinuria,” was presented at a poster session at the EHA Congress on Saturday, June 6 by Ilene Ceil Weitz, M.D., Assistant Clinical Professor of Medicine, Jane Anne Nohl Division of Hematology, Keck School of Medicine of the University of Southern California.

Dr. Weitz presented additional results from an ongoing prospective study to measure the effect of Soliris therapy on measures of inflammation and thrombin generation in patients with PNH.