FDA approves Eisai-Biogen Alzheimer’s drug

Jan. 9, 2023

Late last week, the U.S. FDA approved Eisai and Biogen's co-developed Alzheimer’s disease anti-amyloid beta protofibril antibody, lecanemab, under an Accelerated Approval pathway.

The drug had a few controversial months leading up to its approval. In November of 2022, two clinical trial deaths were linked to the drug being used in combination with blood thinners. At the time, the neuropathologist who was involved in one of the patient’s autopsy said in a statement to Science that he believed that “This is a treatment-caused illness and death. If the patient hadn’t been on lecanemab she would be alive today.”

But lecanemab — to be sold as Leqembi — was still cleared for approval using the Accelerated Approval pathway, which allows the FDA to approve drugs for serious conditions where there is an unmet medical need and a drug is shown to have an effect on a surrogate endpoint that is reasonably likely to predict a therapeutic benefit to patients.  According to Eisai, the drugmaker plans to work quickly to file a Supplemental Biologics License Application (sBLA) to the FDA for approval under the traditional pathway.

To confirm the drug’s efficacy and safety, the FDA looked at a double-blind, placebo-controlled, parallel-group, dose-finding study of 856 patients with Alzheimer’s disease.  According to trial results those patients receiving the treatment had significant dose- and time-dependent reduction of amyloid beta plaques. 

The FDA had also granted the application Fast Track, Priority Review and Breakthrough Therapy designations. 

With lessons learned from Aduhelm, Eisai has focused on obtaining payer coverage for Leqembi.

Last year, citing unconvincing demonstrations of Aduhelm's effectiveness, the U.S. Medicare program decided to cover the drug only for patients who were participating in clinical trials. Although forecasted to become the best-selling drug of all time, Aduhelm tanked when it went on the market, pulling in just $30,000 in sales in the third quarter — well below its expected $10.79 million.

But the Centers for Medicare and Medicaid Services (CMS) has committed to quickly reconsider National Coverage Determination (NCD) once an anti-amyloid drug is approved. Eisai believes Clarity AD has a robust design, which could meet the “high level of evidence” criteria set forth by CMS in the NCD decision memo if the result is positive; therefore, creating the potential for CMS to reconsider full coverage of Leqembi.

Eisai estimates the per-patient-per-year value of Leqembi to the U.S. society to be $37,600, but says it will price the drug at $26,500 per year.