Alexion Pharmaceuticals has paused further enrollment in a phase 3 study evaluating ravulizumab-cwvz (Ultomiris®) in adults with severe coronavirus disease 2019 (COVID-19) requiring mechanical ventilation due to a lack of efficacy.

The open-label, controlled study enrolled adults hospitalized with COVID-19 and severe pneumonia, acute lung injury or acute respiratory distress syndrome. Patients were randomized to receive ravulizumab-cwvz plus best supportive care (BSC) or BSC alone. The primary end point was survival at day 29.

A review of data from a pre-specified interim analysis showed a lack of efficacy when ravulizumab-cwvz was added to BSC in 122 patients who completed the 29-day primary evaluation period. The decision to pause enrollment was made based on a recommendation from the study’s independent Data Monitoring Committee (DMC). The study will continue for patients already enrolled; no new safety findings were identified.

“We are disappointed in this initial outcome, but plan to further analyze the data to identify potential subgroups who may benefit and to determine next steps,” said John Orloff, MD, Executive Vice President and Head of Research & Development at Alexion.

Ultomiris is currently approved as a treatment for paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome to inhibit complement-mediated thrombotic microangiopathy.

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Alexion provides update on phase 3 study of Ultomiris® (ravulizumab-cwvz) in hospitalized patients with severe COVID-19. [press release]. Boston, MA: Alexion Pharmaceuticals; January 13, 2021.