ProMIS Neurosciences reported interim safety data from a blinded analysis of an Alzheimer’s clinical trial combining its amyloid-targeting approach with placebo. The company said the pooled rate of ARIA was 4.4%, with all ARIA cases characterized as mild and asymptomatic, and no instances of ARIA-E. The interim readout is positioned as a potential safety signal relative to ARIA outcomes seen with earlier amyloid-targeting therapies. The update was framed around pooled data from patients receiving the ProMIS drug versus placebo and comes ahead of future reporting milestones. If sustained in later datasets, the profile could affect trial design decisions for dose, escalation, and inclusion criteria—particularly in populations at higher baseline risk for vascular permeability–linked complications. However, the company’s headline focus remains on safety, not efficacy. Still, for developers in the AD space, any ARIA signal strong enough to influence dosing risk calculations can shift how fast programs progress into pivotal-stage planning.