After dragging investors through the Aduhelm debacle, Biogen (BIIB) may soon have a shot at redemption.
The company's partner Eisai (ESALY) announced that a separate Alzheimer's drug candidate, lecanemab, succeeded in a late-stage study. The pair own joint rights to the asset. The experimental treatment was reported to have easily met all primary and secondary endpoints measured in the phase 3 clinical trial. Detailed results will be withheld until a medical presentation in November.
Investors may not mind the vagueness. The U.S. Food and Drug Administration (FDA) is already reviewing a marketing application for lecanemab based on clinical data through phase 2 studies. Delivering success in the larger confirmatory trial would likely all but guarantee an eventual approval, even if regulators delay a decision to digest the new data.
What happens now?
Early Signs of Clinically Meaningful Outcomes
Eisai enrolled 1,795 individuals with early Alzheimer's disease in the late-stage study. Half received lecanemab and half received a placebo. All individuals were followed for at least 18 months.
Preliminary results show the experimental treatment slowed cognitive decline at 18 months by 27% compared to placebo, as measured by a widely-used functional scale. Improvements were seen as early as six months into treatment and maintained across all timepoints. It was a no-doubter from a statistics point of view.
All key secondary endpoints, including clinically measured levels of amyloid plaques and additional functional grading scales, also achieved statistically significant improvements in the lecanemab group. Treatment was generally well tolerated.
The results are surprising for multiple reasons. First, lecanemab works by reducing amyloid levels in the brain. So did Aduhelm. The beta amyloid hypothesis of Alzheimer's disease progression suggests the buildup of plaques is what leads to dementia. Although dozens of drug candidates have been designed to reduce amyloid levels, the hypothesis was dealt a huge blow this summer after reports emerged that the original dataset was manipulated.
Second, lecanemab has delivered mixed results in earlier clinical trials. Eisai and Biogen even announced the drug candidate was unlikely to succeed in the phase 2 study in 2017, only to later find positive trends in certain groups of patients. Other drug developers have said similar things in the past after diving into clinical data, but later studies have never confirmed the results--until now.
What Happens to Biogen Now?
Let the rollercoaster ride continue. Biogen and Eisai are awaiting an approval decision from the FDA by January 6, 2023. Regulators are only considering phase 2 clinical data, but any approval would be conditional pending the results of a larger confirmatory study.
With that data now in hand, regulators may decide to delay the decision date and evaluate the phase 3 results. The FDA may also feel pressured to approve the first Alzheimer's disease treatment that actually has a measurable benefit on dementia symptoms. Then again, regulators used that logic to approve Aduhelm before confirmatory studies delivered results, which backfired.
Investors and analysts will also be eagerly awaiting fuller details from the late-stage study when Eisai presents at the Clinical Trials on Alzheimer’s Congress in late November 2022.
Wall Street may not wait to pencil in a higher probability of success for lecanemab, which would lead to an impressive rise in Biogen and Eisai shares. Any price appreciation may not match the euphoria that followed Aduhelm's approval decision, but it should still be significant by large-cap pharma standards. The news could also catalyze shares of Eli Lilly (LLY) and Roche (RHHBY) , which are each developing a very similar drug candidate to lecanemab.
Either way, this appears to be the first time a drug candidate in Alzheimer's disease has delivered a clinically meaningful benefit in a phase 3 clinical trial. That's something to celebrate.
