Antibody fragment prevents hemorrhages associated with new Alzheimer's treatments

In 2025, the European Medicines Agency approved two antibodies for Alzheimer's disease: lecanemab (LeqembiTM, from Biogen) and donanemab (Kisunla, from Eli Lilly and Co.), both based on immunotherapy (the use of molecules from the immune system to treat diseases).

These antibodies, obtained in the laboratory, act against the Aβ peptide, a protein fragment that accumulates in the brains of patients with Alzheimer's disease.

Elimination of this protein by the immune system helps slow the characteristic cognitive decline of the disease. ...