“The second trial did not meet the primary endpoint. In all studies in which it was evaluated, however, Aduhelm consistently and very convincingly reduced the level of amyloid plaques in the brain in a dose- and time-dependent fashion. It is expected that the reduction in amyloid plaque will result in a reduction in clinical decline.”
From the FDA’s statement on the approval. They have approved the drug for its ability to decrease plaques, with the expectation that it also prevents cognitive decline. They essentially ignored the main clinical purpose of the drug and instead approved it based solely on it’s mechanism of action. It’s a joke that it was approved, especially that it was approved for all Alzheimer’s patients instead of only patients with mild Alzheimer’s which the trials screened.