AstraZeneca division Alexion is to discontinue the international Phase III CHAMPION-ALS clinical trial of its drug, Ultomiris (ravulizumab), for the treatment of amyotrophic lateral sclerosis (ALS).

A long-acting C5 complement inhibitor, Ultomiris provides quick, complete and long-lasting complement inhibition.

The drug acts by hindering the C5 protein in the terminal complement cascade, a part of the immune system of the body. When activated uncontrollably, the complement cascade over-responds and causes the body to attack its healthy cells.

Ultomiris is given as an intravenous dose every eight weeks, or every four weeks for children weighing less than 20kg, after a loading dose.

The latest development comes after the Independent Data Monitoring Committee (IDMC ) reviewed the Phase III CHAMPION-ALS trial data from a pre-specified interim analysis and recommended discontinuation due to no efficacy.

The randomised, double-blind, placebo-controlled, multi-centre trial analysed the efficacy and safety of Ultomiris in 382 adults with sporadic or familial ALS enrolled at nearly 90 sites across North America, Europe and Asia.

These subjects had developed the disease in the form of initial motor symptoms within the previous 36 months, showed a slow vital capacity (SVC) of a minimum of 65% predicted and were independent of respiratory support.

The change in ALS functional rating scale-revised (ALSFRS-R) score was the trial’s primary goal.

No new safety findings were reported in the trial with the results in line with the already known safety profile of the drug.

Alexion senior vice-president and development and safety head Gianluca Pirozzi said: “We are disappointed by this outcome and what it means for patients with this devastating disease.

“We continue to be confident in the potential of targeting C5 for complement-driven diseases and remain fully committed to our efforts to serve the rare disease community.”

Trial subjects will discontinue treatment with Ultomiris and conclude any required follow-up analyses, the company noted.

Last month, AstraZeneca acquired US-based biopharmaceutical company Alexion Pharmaceuticals for a total consideration of $39bn or $175 a share.