Lack of efficacy brought the development of two investigational agents for amyotrophic lateral sclerosis (ASL) to a halt over the past week. On May 23, Wave Life Sciences Inc. disclosed that its stereopure antisense oligonucleotide WVE-004 failed to demonstrate clinical benefit after 24 weeks of treatment on a phase Ib/IIa trial in familial ALS patients or frontotemporal dementia patients. And on May 25, Apellis Pharmaceuticals Inc. and its partner, Swedish Orphan Biovitrum International AB, said that pegcetacoplan failed to meet its primary endpoint of a one-year phase II trial in patients with sporadic disease.