Novartis AG (NYSE: NVS) has discontinued development of an experimental drug for amyotrophic lateral sclerosis, commonly known as ALS or Lou Gehrig's disease, after a mid-stage clinical trial failed to demonstrate the treatment worked better than a placebo in slowing disease progression.

The company confirmed the decision in an emailed statement. The discontinued drug, VHB937, is a monoclonal antibody that researchers had hoped would engage the immune system to protect brain cells from damage.

ALS is a fast-progressing neurological condition that causes paralysis, difficulty swallowing, and trouble breathing.