After decades of trying and dozens of failed trials, amyloid targeting has paid off with the first disease-modifying agents reaching the market. But success does not mean slam dunk. Aduhelm (aducanumab, Biogen Inc.) was dogged by controversy throughout its brief tenure, and Biogen pulled the plug on it in early 2024. Leqembi (lecanemab, Biogen Inc.) has received full approval. In this second installment of a three-part series on Alzheimer’s, BioWorld looks at the nuanced view of amyloid’s role in the disease.