FDA approves lecanemab under its accelerated approval.

https://www.fda.gov/news-events/press-announcements/fda-grants-accelerated-approval-alzheimers-disease-treatment

Accelerated approval allows for approval if a drug fills an unmet need for a serious condition based on a surrogate endpoint instead of clinical benefit. The approval can be revoked later if the clinical benefit is not realized or has an unfavorable safety profile.

I posted the trial data that supported this approval earlier. Lecanemab had a statistically significant reduction in Clinical Dementia Rating-Sum of Boxes score, a first for an Alzheimer's drug. However questions remain on if this will translate to a meaningful clinical improvement in patients. There are also adverse effects that may limit the use of the drug.

This would join the controversial Alzheimer's drug aducanumab that was also granted accelerated approval earlier. Both drugs are anti-amyloid monoclonal antibody therapies. Though lecanemab's preliminary data is a bit stronger than aducanumab’s.

This doesn't necessarily guarantee access to the drug. CMS has restricted Medicare coverage of this class of drugs given the issues with aducanumab. It will also be very expensive like aducanumab.

Far too early to say if this is a game changer for Alzheimer's- that's what hopefully will be determined with more data during accelerated approval- but it is notable progress that potentially could help slow the progression of the disease.