What does the drug do?

Ultomiris is a monoclonal antibody designed to bind and inhibit the activity of the C5 protein, preventing overactivation of the complement system — a set of more than 20 blood proteins forming part of the body’s innate immune defences.

Ultomiris is approved in the U.S. for two serious blood disorders — paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome — caused by an abnormal complement system, and evidence points to a potential benefit in ALS patients, as proteins of the complement system have been implicated in disease onset and progression of motor symptoms.

Trial Outcome

The trial was discontinued due to lack of benefit in people living with MND.

Clinical Trials


The Phase 3 clinical trial to test its complement system inhibitor Ultomiris (ravulizumab) in ALS — expected to recruit over 350 patients with familial or sporadic ALS. The trial had planned to run for 50 weeks with participants randomly assigned to receive Ultomiris or placebo once every 8 weeks. You can read more about the trial here.


In August 2021, Alexion announced the discontinuation of the Phase 3 trial of Ravulizumab (CHAMPION-ALS) as an interim analysis showed a lack of efficacy, meaning it was found to have little benefit in people living with MND. You can read more here.

Last updated: 21/12/2022