Biogen and Eisai announced yesterday that their investigational Alzheimer’s disease (AD) treatment lecanemab has received a breakthrough therapy designation (BTD) from the US Food and Drug Administration (FDA).

Lecanemab – also known as BAN2401 – is an investigational anti-amyloid beta protofibril antibody, designed to treat AD.

The BTD for lecanemab is based on data from a Phase IIb clinical trial including 856 patients with mild cognitive impairment due to AD and mild AD with a confirmed presence of amyloid pathology.

In this study, a pre-specified analysis showed consistent reduction of clinical decline across a number of clinical and biomarker endpoints at the highest doses.

Following this, Biogen and Eisai completed enrolment of 1,795 patients with early AD in the Phase III Clarity AD study.

The companies are expected the study’s primary endpoint to be completed by the end of September 2022.

On top of that, another Phase III clinical study – AHEAD 3-45 – is currently exploring lecanemab in preclinical AD patients, meaning that they have intermediate or elevated levels of amyloid in their brains but are clinically normal.

Earlier this month, Biogen and Eisai’s other AD drug aducanumab made history after gaining accelerated approval from the FDA, making it the first new treatment approved for AD in over a decade.

The accelerated approval for aducanumab – now known as Aduhelm – was supported by three studies of the drug involving 3,482 patients.

The continued approval of Aduhelm in Alzheimer’s is contingent on the verification of its clinical benefit in confirmatory trials.