Breakthrough therapy designated for Lilly’s investigational Alzheimer’s drug donanemab

The US Food and Drug Administration (FDA) has granted Eli Lilly’s investigational Alzheimer’s disease drug donanemab a breakthrough therapy designation (BTD).

The BTD is based on data from the phase 2 TRAILBLAZER-ALZ study – the results of which were revealed earlier this year.

Top-line data from the TRAILBLAZER-ALZ trial in patients with early symptomatic Alzheimer’s showed that donanemab slowed cognitive decline by 32% on the Integrated Alzheimer’s Disease Rating Scale (iARDS) compared to placebo.

Following this, Lilly reported that although secondary outcomes within this trial ‘showed no substantial difference’, exploratory analyses showed donanemab slowed the accumulation of tau across key brain regions in Alzheimer’s patients.

In addition, 40% of donanemab-treated patients achieved amyloid negativity as early as six months after starting treatment and 68% achieved this target by 18 months.

In a statement, Lilly said that it intends to submit a biological licence application (BLA) for donanemab under the accelerated approval pathway later this year, based on data from the TRAILBLAZER-ALZ study.

Lilly is also evaluating donanemab in a phase 3 trial – TRAILBLAZER-ALZ-2 – which is set to enrol 1,000 participants in a bid to confirm the efficacy and safety of donanemab in a larger population of Alzheimer’s patients.

The initial phase 2 trial included patients with early symptomatic Alzheimer’s disease who had tau and amyloid deposition on a Positron emission tomography (PET) scan.

The study enrolled a total of 257 patients, with 131 assigned to receive donanemab and 126 to receive placebo.

Lilly has enrolled patients in the expanded TRAILBLAZER-ALZ 2 study who have both high and intermediate levels of tau accumulation, but participants who have high tau levels will be excluded from the primary analysis of the trial.

The company is expecting to complete enrolment of participants in this study later this year, with data from the trial anticipated in early 2023.