Roche's Genentech is launching a second Phase III trial of anti-Abeta antibody crenezumab in patients with early forms of Alzheimer's disease (AD), on the back of promising data on the drug's "unique" binding properties and in support of increased dosing.

The new trial - CREAD2 - intends to recruit 750 patients with prodromal or mild AD, complementing the ongoing Phase III CREAD1 trial, which is assessing the drug in the same patient target group and is expected to read out in 2020.

Roche presented data from two Phase II studies investigating whether crenezumab can delay cognitive and functional decline in people with mild-to-moderate AD back in 2014, showing that proof-of-concept study failed to meet its primary endpoint.

However, the study did demonstrate initial evidence of a crenezumab treatment effect in people with mild AD, and similar effects on clinical decline were observed in BLAZE, a smaller biomarker study, the firm noted.

The move to kickstart a second Phase III signals a continued confidence in drug, and will likely raise hopes for a new treatment for the disease following a stream of recent high profile failures in the field.

"Given the recent disappointing results of other therapies, all of us in the Alzheimer's community need to redouble our efforts to combat one of society's biggest challenges," said Professor Andrea Pfeifer, chief executive of AC Immune, which discovered the drug.

"We remain confident about the potential of crenezumab given it is distinct from other beta amyloid antibodies, predominantly blocking oligomers in the brain, and has a clinical development program that is using higher dosing and targeting earlier stages of Alzheimer's disease."

Crenezumab is a fully humanised IgG4 monoclonal antibody that binds all forms of misfolded Abeta proteins to prevent and break up their aggregation and promote their disaggregation.

The drug was discovered by AC Immune using its SupraAntigen technology platform and out-licensed to Genentech in 2006 as a potential therapy for Alzheimer's.