AstraZeneca and Eli Lilly have begun a major trial for patients with early-stage Alzheimer's disease.

Enmrolment has begun for a Phase II/III study of AZD3293, an oral beta secretase cleaving enzyme (BACE) inhibitor. The two-year study aims to enrol more than 1,500 patients in 15 countries with early-stage Alzheimer’s.

AZD3293, also known as LY3314814, has been shown in Phase I to reduce levels of amyloid-beta in the cerebro-spinal fluid of Alzheimer’s patients and healthy volunteers. BACE is an enzyme associated with the development of beta-amyloid and inhibiting it is expected to eventually slow progression of the disease.

Samantha Budd, head of translational science in AstraZeneca’s neuroscience innovative medicines unit said there is “a critical need” to develop drugs that can “change the course of Alzheimer’s. We believe that BACE inhibitors have the potential to target one of the key drivers of this devastating disease [and] together with Lilly, we have unique expertise”.

The companies linked up for AZD3293 in September in an alliance that could net AstraZeneca up to $500 million in development and regulatory milestone payments.