Biogen gains fast-track Alzheimer’s drug review in wake of early data

After releasing early data just a day ago that grabbed international headlines, now Biogen ($BIIB) has disclosed that its aducanumab to treat Alzheimer’s disease has been granted fast-track designation from the FDA.

It follows in the footsteps of another Alzheimer’s disease candidate from partners Eli Lilly ($LLY) and AstraZeneca ($AZN) that a couple of weeks ago got the same designation for their Phase III BACE inhibitor AZD3293. The Biogen candidate is earlier stage, but aducanumab is moving along quickly. The newly reported data is preclinical and Phase Ib; the candidate is already in a pair of Phase III trials, both in early Alzheimer’s patients.

In the Phase Ib, placebo-controlled trial in 165 prodromal (or predementia) and mild AD patients, aducanumab was found to reduce amyloid-beta in the brain in a dose-dependent fashion. Exploratory data in that trial also found dose- and time-dependent slowing of clinical decline.

“The combination of a much better understanding of disease biology, the focus on genetically validated targets, the use of biomarkers to learn early whether or not our compounds are having the desired biological effects, and the adoption of multiple therapeutic modalities may meaningful increase success rates and identify those projects likely to fail early in the process, before large amounts of time and money are spent,” Biogen CEO George Scangos summed up on a conference call earlier this year of the company’s neurodegenerative research, in general, and aducanumab, in particular.

The Phase III aducanumab trials differ from the Phase Ib in so far as they aim for "early” Alzheimer’s patients rather than the slightly different grouping of “prodromal or mild” patients in the earlier trial.

The Phase III trials started in the fall of 2015 and are each slated to enroll about 1,350 patients, according to information on Clinicaltrials.gov. Primary outcome data for each is slated for early 2020, with the studies to complete in in early 2022.

The primary outcome for each of the Phase III trials is changes in the Clinical Dementia Rating-Sum of Boxes (CDR-SB) score as compared with placebo in participants with early AD. That’s the same measure that was used to assess clinical decline in the Phase Ib trial.

Both of the Phase III studies also include a high and low dose of the monthly intravenous infusion.

Aducanumab was also recently accepted into the European Medicines Agency’s Priority Medicines program, known as PRIME. It is the first and only neurology candidate accepted under the relatively new program, which is designed to enhance access to a speedy assessment for candidates that may offer benefit in an area where there is no treatment.

As a company, Biogen is itself in the midst of turmoil as long-standing leader George Scangos is slated to depart. In July, he said he expected to leave the company in “a few months” once a successor was found. Biogen has been widely viewed as a potential acquisition candidate, as it remains unclear how it will fuel the next leg of long-term revenue growth as its prior multiple sclerosis-driven expansion has slowed.

Aducanumab is a human recombinant monoclonal antibody derived from a deidentified library of B cells collected from healthy elderly subjects with no signs of cognitive impairment or cognitively impaired elderly subjects with unusually slow cognitive decline. It was in-licensed from Neurimmune under a collaboration that dates back to 2007.