ProMIS Neurosciences reported an interim safety analysis in its amyloid-targeting Alzheimer’s trial, describing low rates of brain bleeding and no brain swelling in a blinded safety assessment versus placebo. The pooled analysis reported ARIA total at 4.4%, with all events mild and asymptomatic. The company said there were no ARIA-E cases, which are associated with vasogenic edema and swelling. Instead, reported events were characterized as ARIA-H, indicating microbleeds without the more severe swelling signal. If confirmed at full readouts, the data would support continued dose and regimen evaluation in Alzheimer’s—where safety has been a central determinant of whether amyloid-directed approaches can sustain long-term use. Market reaction in the broader ecosystem will depend on whether the safety profile translates into tolerability sufficient for efficacy expansion in later-stage follow-up.