Alzheimer has always been a sophisticated issue lingering around scientists mind, trying to define its neurological cause and pertinent treatment. Currently, a newly developed drug, lecanemab, shows significant results in trial in abating the mental decline of Alzheimer patients. However, as some consider the drug prospective, others show less trust to its credibility.
Lecanemab, invented by Eisai, a medical company in Tokyo, and Biogen, corporation of biotechnology in Cambridge, was reported to have a 27% decrease in the rate of cognitive decline of Alzheimer patients. The drug aims to reduce the protein amyloid-β, whose accumulation, in the theory of ‘amyloid hypothesis’, is believed to be attributable to Alzheimer disease.
Contrary to the antibody Biogen previously launched, aducanumab, which only received incomplete experiment and subtle cognitive effect, the new research team of Eisai and Biogen ran a total of 18 months’ experiment without disruption in order to test the efficacy of lecanemab. Promising results have been revealed in about 1,800 early-stage Alzheimer patients.
In the process of assessment, Clinical Dementia Rating–Sum of Boxes (CDR–SB) , an 18-point scale, was deployed to evaluate the rate of cognitive decline through interviews and examination of memory, etc. Further research displays a decrease in amyloid after infusion of lecanemab as well as a 0.45 points better results in CDR-SB than placebo group.
Some scientists are highly expecting more application of the drug, referring to the mollified cognition decline as ‘such a win for our field.’ ( by Liana Apostolova, a neurologist at the Indiana University School of Medicine in Indianapolis)
The Alzheimer’s Association, a funder and organization for Alzheimer patients, expresses that ‘these are the most encouraging results in clinical trials treating the underlying causes of Alzheimer’s to date.’
However, not all researchers advocate for the lecanemab drug and the ‘amyloid hypothesis’.
Despite agreeing that the results look ‘promising’, Caleb Alexander, an advisory committee member for the US Food and Drug Administration (FDA) and an medicine specialist at the Johns Hopkins Bloomberg School, still holds a cautious viewpoint that ‘we’ll have to see what the full analysis of the trial suggests’.
Also, George Perry, a neurobiologist at the University of Texas at San Antonio, refuted that amyloid probably ‘isn’t the problem’, for that in every modulation, ‘of course you can have some small benefit.’
The minute extent to which lecanemab can influence Alzheimer patients render scientists skeptical as well. A 0.45 points higher in an 18-points scale of CDR-SB is a ‘really tiny and almost unnoticeable difference from placebo’, says Rob Howard, a psychiatrist at University College London. Researchers are prone to believe a more higher difference, such as a range of 0.5 to 2 points.
The controversial nature of lecanemab consequently receives attention from FDA.
Previously, the FDA has approved the usage of aducanumab in treating Alzheimer patients, for it has certain effect in reducing amyloid. Lecanemab may follow suit due to similar effects. FDA is attempting to deliver an announcement on 6 January, after all research data has been released.
The potential success of lecanemab encourages more researchers to shed light on the field. Biotech firm Roche, based in Basel, Switzerland, and Eli Lilly, in Indianapolis, will release their results for tested antibody, gantenerumab and donanemab, respectively.
Some scientists have pointed out another explanation of the disease, that ‘there is a very detrimental second protein called tau that needs to be addressed,’ says Apostolova, a former counselor for Biogen and Eisai. She indicates that tau, which is appeared in the brains of Alzheimer patients, ‘is actually the one that really strongly correlates with cognitive decline.’ This leads to the combined approach that targets both the amyloid and tau.
Whether or not lecanemab can be further applied in clinical usage, a more holistic and effective approach with less side-effect should be the purpose of thorough research.