Promising preliminary results from a trial of the Alzheimer’s drug donanemab,  first announced in May, have now been confirmed.  

The full results were made public today at the Alzheimer’s Association International Conference by the pharmaceutical company Eli Lilly, which manufactures the drug. 

The findings, which are published in the Journal of the American Medical Association, confirm that donanemab was able to slow clinical decline by 35% in people with early Alzheimer’s whose brain scans showed low or medium levels of a protein called tau. However, it had no effect in people with high tau levels.  

Alzheimer’s Research UK’s Executive Director of Research & Partnerships, Dr Susan Kohlhaas, hailed the results as “another milestone” that confirmed “the outlook for dementia and its impact on people and society is finally changing”.  

The findings also confirmed the drug’s side effects, which – for some – can be serious and require careful monitoring. 24% of people on the trial receiving donanemab were reported to have experienced side effects. This included brain swelling and infusion-related reactions. 4 participants died during the trial, with their deaths thought to be related to the drug’s side effects. 

Lilly’s trial, known as TRAILBLAZER ALZ-2, included nearly 1,800 people with early-stage Alzheimer’s disease. Participants received a monthly infusion of either donanemab or a dummy drug (placebo) over 18 months. People who received donanemab were able to continue to perform day-to-day activities including shopping, housekeeping, managing finances and taking medication. However, it also caused serious side effects for some participants. “Regulators will need to balance these benefits and risks before it is given a license for use,” said Dr Kohlhaas.  

In response to the drug’s successes, Alzheimer’s Research UK has written to Eli Lilly calling on them to put donanemab forward for regulatory review in the UK without delay. “We believe this review should be conducted by the UK regulators as a priority,” said Dr Kohlhaas. 

Drugs like donanemab will also pose several challenges for the NHS, not least how people eligible to receive these treatments are identified, diagnosed and monitored. Dr Kohlhaas said Alzheimer’s Research UK are pushing for collaborative and constructive dialogue between leadership at NHS England, drug manufacturers, the MHRA, NICE, the Association of British Neurologists, the Royal College of Psychiatrists and people affected by Alzheimer’s disease, to make sure any treatments that are licensed can be made available to those who might benefit without delay. 

And Dr Kohlhaas also called for further investment in research. “We owe it to people living with dementia now, and to future generations, to use this moment to invest in future treatments that will transform the lives of people with dementia even more,” she said. 

Alzheimer’s Research UK