On 4 November, the FDA released documents noting support for the safety and efficacy of Biogen’s treatment for Alzheimer’s disease (AD), aducanumab. It is looking very likely that the drug will become the first new AD therapy to be approved in 17 years and if it is approved, the drug could be in the market by March 2021.
Even before this positive response, GlobalData expected global sales of Biogen’s aducanumab to be high, equaling $4.1B in 2028 across eight major markets (8MM: US, France, Germany, Italy, Spain, UK, Japan and China). There are currently no disease-modifying therapies (DMTs) for this indication—and no close competitors in the late pipeline—offering aducanumab a huge advantage. The drug’s potential approval will only strengthen Biogen’s position, and in a nod to that, its shares surged 40% to $354.25 by Wednesday, adding $17B to the company’s market value.
Aducanumab is a recombinant human monoclonal antibody (mAb) that binds primarily to aggregated forms of Aβ, including soluble oligomers and insoluble fibrils, but reportedly does not bind Aβ monomers. Aducanumab’s two main Phase III studies, ENGAGE and EMERGE, were halted in March 2019 as a futility analysis concluded that that trials would not reach their primary endpoint, the slowing of cognitive decline as measured by the CDR-SOB. However, in October 2019, Biogen announced that it was seeking FDA marketing approval of aducanumab, as upon re-analysing data from the trials, the EMERGE trial showed significant findings and a subset from the ENGAGE trial supports these positive findings.
Key opinion leaders (KOLs) interviewed by GlobalData expressed mixed opinions about the potential approval from the FDA, noting that the cumulative data around efficacy and safety for aducanumab are not substantial enough to meet the FDA’s standard. This concern was also expressed by a few FDA reviewers, who asked for an additional trial to confirm the evidence of aducanumab in slowing the disease. However, KOLs believe that the FDA is unlikely to turn down aducanumab—even if its benefit is modest—given the lack of any therapy that is truly efficacious in the space.
There is a high unmet need for DMTs in AD as the current competitive landscape offers six medications that are aimed at treating the symptoms of the disease: three ChEIs (donepezil, rivastigmine, and galantamine), one NMDA-R antagonist (memantine), one combination therapy (memantine/donepezil), and one Aβ A4 protein inhibitor (sodium oligomannate). KOLs interviewed by GlobalData indicated that due to the lack of DMTs, any agent that can reverse or stop the underlying pathology of the disease will become a key therapy in disease management.
Among decisions being made Friday, when the FDA comes to its final decision on the drug’s approval, is whether aducanumab’s solution for intravenous infusion will attain its biologics license. Aducanumab’s infusion route of administration could be an issue where infusion centres aren’t available, and concerns regarding the developing of amyloid-related imaging abnormalities (ARIA) can represent a barrier for the drug’s uptake. Physicians also will be obliged to perform regular MRI scans on patients to see if they have ARIA reactions, which could serve as a limitation from an economic point of view.