Acumen Pharmaceuticals (NASDAQ: ABOS) presented new preclinical and clinical data at the Alzheimer's Association International Conference (AAIC) 2026 in London, including findings from its Enhanced Brain Delivery (EBD) program developed in collaboration with JCR Pharmaceuticals.

In studies using cynomolgus monkeys, three bispecific antibodies combining an anti-amyloid beta oligomer (AβO) antibody with anti-transferrin receptor fragments achieved greater brain exposure than the unmodified antibody alone. Lead candidate ACU401 showed 22-fold higher frontal cortex levels at three hours post-dose and 40-fold higher levels at 24 hours, with similar results observed in the hippocampus and putamen. No hematological findings associated with anemia were reported. Systemic absorption was also confirmed following subcutaneous dosing.

Earlier mouse studies showed that fusion with anti-transferrin receptor fragments did not alter AβO binding affinity or selectivity, and all EBD constructs achieved higher brain levels than native anti-AβO antibodies. The constructs also retained the ability to bind amyloid beta species in human Alzheimer's disease brain tissue.

"Confirming our mouse data in non-human primates is a pivotal step for our EBD program," said Paul Shughrue, PhD, Vice President and Head of Research at Acumen Pharmaceuticals. "The degree of brain penetration we observed in cynomolgus monkeys, combined with preserved soluble amyloid beta oligomer selectivity and a clean hematological profile, exceeded our expectations."

Acumen also presented patient experience data from its ongoing ALTITUDE-AD Phase 2 trial. Semi-structured interviews conducted with 38 participants and their study partners prior to treatment identified memory-related challenges, emotional impacts including frustration and worry, and coping behaviors such as symptom masking. The ALTITUDE-AD trial has enrolled 542 participants across sites in the United States, Canada, the European Union, and the United Kingdom, with topline results expected in late 2026.

The data presented are based on information from an Acumen Pharmaceuticals press release.