Biogen and Eisai Secure Traditional FDA Approval for Lequembi

On July 6, 2023, the FDA granted Biogen Inc and Eisai Co’s Lequembi traditional FDA approval. The approval was based on a supplemental Biologics License Application (sBLA) and prior accelerated approval awarded in January 2023.

Lequembi, also known as lecanemab-irmb, is an injectable humanized immunoglobulin gamma 1 (IgG1) monoclonal antibody that targets insoluble amyloid beta (Aβ) plaques and protofibrils, soluble Aβ of 75–5000 Kd. The drug is intended for patients with Alzheimer’s Disease (AD) who have mild cognitive impairment or are in the mild dementia stage of illness.

While the drug will not cure AD, it is the first and only FDA-approved medication proven to slow cognitive and functional decline, delaying disease progression in patients with AD.

“Today marks a breakthrough in the treatment of Alzheimer’s disease, and we are proud to be at the forefront of ushering in a new era of advances for a disease that was previously considered untreatable. We would like to express our sincere appreciation to those who have worked tirelessly to find a treatment for this unrelenting disease, without whom this progress would not be possible,” said Christopher A. Viehbacher, President and Chief Executive Officer of Biogen, in the press release. "Our focus is now on the path forward, working alongside Eisai with the goal of making LEQEMBI accessible to eligible patients as soon as possible.”

The sBLA that prompted FDA officials to approve Lequembi traditionally included data from Eisai’s phase 3 clinical trial. The Clarity AD trial was a large global study assessing the efficacy of Lequembi, using cognitive and functional decline as the primary endpoint.

Researchers assessed patients with the Clinical Dementia Rating Sum of Boxes (CDR-SB) scale, finding that patients taking Lequembi had a 27% lower clinical decline in cognition and function compared to the placebo.

In addition, researchers evaluated mild cognitive impairment using the AD Cooperative Study Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS MCI-ADL) based on participant caretaker reports. This scale assesses how well a patient can function independently. According to the study, patients taking Lequembi had a 37% benefit.

Beyond securing traditional FDA approval, the Centers for Medicare and Medicaid Services (CMS) announced that it would expand coverage of Lequembi using a registry and data submission process. As the drug rolls out, healthcare professionals must evaluate whether their patients qualify for treatment and how this medication may be integrated into existing regimens.