Alexion to Receive Priority Review for Ravulizumab as Eculizumab Biosimilars Close In

Drug maker Alexion, developer of the rare disease drug eculizumab (Soliris), announced Friday that the FDA has accepted for priority review its long-acting C5 complement inhibitor, ravulizumab (Ultomiris), which offers less frequent administration than eculizumab. The FDA will review ravulizumab for the treatment of atypical hemolytic uremic syndrome (aHUS), a progressive disease that can lead to irreversible organ damage and premature death.

Alexion expects a regulatory decision by October 2019.

“This acceptance is an important step in our efforts to deliver a potential new standard of care to people living with this devastating disease,” said John Orloff, MD, executive vice president and head of research and development at Alexion. “We look forward to working closely with the FDA to facilitate a rapid review of this application.”

Earlier this year, Alexion announced that its study in 56 patients with aHUS had met its primary end point; in the first 26 weeks of treatment, 53.6% of patients (95% CI, 39.6%-67.5%) demonstrated a complete thrombotic microangiopathy response, defined by hematologic normalization and improved kidney function for at least 28 consecutive days.

Ravulizumab, which is administered every 8 weeks versus every 2 weeks for eculizumab, has already gained approval for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), and Alexion is studying the drug in patient with myasthenia gravis (MG).

Alexion noted in its fourth quarter 2018 earnings call that it hopes to transition patients already receiving the older eculizumab (which carries indications in aHUS, PNH, and MG) onto the newer ravulizumab in the near future. Alexion’s chief commercial officer, Bryan Goff, said that the company is hoping for a 70% conversion from eculizumab to ravulizumab within the next 2 years ahead of biosimilar market entry.

Meanwhile, biosimilars of eculizumab are advancing; last week, drug maker Amgen reported data demonstrating pharmacokinetic and pharmacodynamic equivalence of its proposed biosimilar (ABP 959) and the reference eculizumab, and the biosimilar developer is currently recruiting for its phase 3 clinical trial of the biosimilar in PNH.