Eli Lilly’s antiamyloid antibody solanezumab struck out in a highly anticipated phase 3 preclinical treatment study, failing to alter disease progression in people who had amyloid brain plaques but normal cognition.

Solanezumab also failed to clear amyloid brain plaques or halt their continued accumulation in the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) Study. The failure to clear fibrillar amyloid wasn’t a surprise since solanezumab targets soluble amyloid beta. The hope for A4 was that the antibody would prevent further amyloid aggregation, slowing or even halting disease progression.

But according to the trial’s lead investigator Resia Sperling, a neurologist at the Brigham and Women's Hospital, Boston, solanezumab’s very failure further confirms the amyloid hypothesis, which holds that the abnormal brain protein triggers the memory loss and cognitive decline of Alzheimer’s.