Donanemab

[2] The US Food and Drug Administration (FDA) label for donanemab contains a boxed warning about amyloid-related imaging abnormalities.

[2] The treatment was switched to placebo based on a pre-specified reduction in amyloid levels measured by positron emission tomography (PET) at weeks 24, 52, and 76.

The positive result indicated that the participants had excess amyloid protein in the brain depicting an early sign of Alzheimer's disease.

Donanemab was found to be highly immunogenic, creating an immune response that increases the efficiency of the original antibody infused.

Most people developed anti-drug antibodies lowering the drug's effectiveness, with a short half-life of ten days.

[10] It consisted of a trial combining two experimental drugs under Lilly that target separate parts of the amyloid cascade.

The goal of this phase II trial was to see how safe, tolerable, and effective an 18-month term of donanemab alone and in combination with Lilly's BACE inhibitor LY3202626.

It planned to enroll 375 people whose memories had been deteriorating for at least six months and who scored above a certain threshold on the CogState Bridging Test but ended up with 257 participants.

Phase II showed promising results at the beginning without analyzing its effects and the data in detail.

[10] There was an overview on the Integrated Alzheimer's Disease Rating Scale (iADRS) when taking donanemab and the scores were similar to the placebo group, showing no significant difference.

In 2021 the TRAILBLAZER-ALZ trial was completed, indicating the current success of donanemab as it slows down the development of Alzheimer's disease; but with the side effects still being problematic, further investigation was needed.

[10] In May 2023, the company reported its phase III study showed the drug could slow the pace of Alzheimer's disease by 35%.

[2][13][14] The US Food and Drug Administration (FDA) granted the application for donanemab fast track, priority review, and breakthrough therapy designations.

[2] In October 2024, donanemab was approved for medical use in the United Kingdom by the Medicines and Healthcare products Regulatory Agency.

[17] Improvements in amyloid imaging technology have linked the excess Aβ peptide outside the cell with the development of Alzheimer's disease.