Alexion Pharmaceuticals, Inc. (NASDAQ:ALXN) announced on 8/20/18 that the U.S. Food and Drug Administration (FDA) has accepted for review the Company’s Biologics License Application (BLA) for approval of ALXN1210, the Company’s investigational long-acting C5 complement inhibitor, for the treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH). The FDA set a Prescription Drug User Fee Act (PDUFA) date of February 18, 2019, as part of an expedited eight-month review instead of the standard 12-month review following Alexion’s use of a rare disease priority review voucher. The application is supported by comprehensive data from two rigorous Phase 3 clinical trials.
“We are working with the FDA to facilitate a smooth review,” said John Orloff, M.D., Executive Vice President and Head of Research & Development at Alexion. “Building on comprehensive results from the largest-ever Phase 3 development program in PNH, 11 years of proven efficacy and safety with Soliris®, and 25 years of leadership in complement biology, we are on track with our efforts to establish ALXN1210 as the new standard of care for patients with PNH.”
If approved, ALXN1210 would be the first and only long-acting complement inhibitor for patients with PNH, providing immediate and complete inhibition of the C5 complement protein that is sustained over an eight-week dosing interval. The Phase 3 clinical development program of ALXN1210 is the largest-ever Phase 3 program in PNH. The studies enrolled a very broad and diverse population of more than 440 patients, which included patients who had never been treated with a complement inhibitor and patients who were stable on Soliris and switched to ALXN1210. Topline data were disclosed in press releases on March 15, 2018 and April 26, 2018, respectively.
ALXN1210 is a long-acting C5 inhibitor discovered and developed by Alexion that works by inhibiting the C5 protein in the terminal complement cascade, a part of the body’s immune system that, when activated in an uncontrolled manner, plays a role in severe ultra-rare disorders like paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and anti-acetylcholine receptor (AchR) antibody-positive myasthenia gravis (MG). In Phase 3 clinical studies in complement inhibitor-naïve patients with PNH, and patients with PNH who had been stable on Soliris, intravenous treatment with ALXN1210 every eight weeks demonstrated non-inferiority to intravenous treatment with Soliris every two weeks, with numeric results for all primary and key secondary endpoints favoring ALXN1210. ALXN1210 is also currently being evaluated in a Phase 3 clinical study in complement inhibitor-naïve patients with aHUS, administered intravenously every eight weeks. In addition, Alexion plans to initiate a Phase 3 clinical study of ALXN1210 delivered subcutaneously once per week as a potential treatment for patients with PNH and aHUS.
ALXN1210 has received Orphan Drug Designation (ODD) for the treatment of patients with PNH in the U.S. and EU, and for the subcutaneous treatment of patients with aHUS in the U.S.
Paroxysmal nocturnal hemoglobinuria (PNH) is a chronic, progressive, debilitating, and potentially life-threatening ultra-rare blood disorder that can strike men and women of all races, backgrounds, and ages without warning, with an average age of onset in the early 30s. PNH often goes unrecognized, with delays in diagnosis ranging from one to more than 10 years.2In patients with PNH, chronic, uncontrolled activation of the complement system, a component of the body’s immune system, results in hemolysis (the destruction of red blood cells)4, which in turn can result in progressive anemia, fatigue, dark urine, and shortness of breath. The most devastating consequence of chronic hemolysis is thrombosis (the formation of blood clots), which can damage vital organs and cause premature death.
