A major study has been unveiled which will test three investigational drugs being developed by Eli Lilly and Roche to see whether they can improve Alzheimer’s disease biomarkers and effectively prevent the loss of cognitive function.

The trial will be conducted at the Washington University School of Medicine in St Louis and its supported by the Dominantly Inherited Alzheimer Network, made up of world-leading research centres, the Alzheimer’s Association and the DIAN Pharma Consortium. The latter is composed of 10 drugmakers which submitted more than a dozen  investigational drugs to be considered for the study.

The three chosen treatments each have "a unique approach to counter the toxic effects of amyloid beta", the main ingredient of brain plaques found in Alzheimer’s patients. The drugs are Roche's gantenerumab, an antibody that binds to all forms of aggregated amyloid beta and helps remove them from the brain.

Gantenerumab is currently in a Phase III trial known as SCarlet RoAD, started in 2010, that will test the drug’s ability to stop Alzheimer’s prior to dementia. The other two drugs come from Lilly, notably the much-touted solanezumab, a monoclonal antibody in Phase III which binds to soluble forms of amyloid beta after they are produced. This allows amyloid beta to be cleared before it clumps together to form plaques.

Also selected for potential inclusion in the trial is the US firm's beta-secretase (BACE) inhibitor, a small molecule in Phase II which reduces the amount of amyloid beta proteins produced, slowing the accumulation of plaques.

Roche and Lilly have agreed to make the treatments available at no cost to the investigators and will also provide supporting grants for each drug to help make the trial possible. The study will also be supported by a $4.2 million grant from the Alzheimer’s Association. and the researchers have applied for support through the National Institutes of Health.

The trial will involve 160 people who have inherited mutations that mean they are almost certain to develop Alzheimer’s at a young age, typically in their 30s, 40s or 50s. The trial also will monitor the health of 80 DIAN participants who did not inherit the Alzheimer’s mutations.

The first part of the trial is planned to last for two years. It will be extended if one or more of the drugs are effective in slowing or stopping indicators of presymptomatic Alzheimer’s. Jan Lundberg, head of Lilly Research Laboratories, said that "we look forward to collaborating with the DIAN TU investigators, along with the other public and private partners, to better understand if early treatment with these investigational medicines can influence this terrible disease".