July 13, 2021
The drugmaker Eli Lilly announced that it will seek fast approval from the Food and Drug Administration for a new drug to treat Alzheimer’s disease. The move comes only weeks after a rival drug company, Biogen, won approval for Aduhelm, the first new drug for Alzheimer’s disease in 18 years.
The move is a reminder of the dozens of novel drugs now undergoing clinical trials for the treatment of Alzheimer’s, and the urgent need for safe and effective medicine that may slow, reverse or even cure the disease. While a handful of drugs have been available to treat Alzheimer’s for the past almost three decades, they may ease some of the symptoms for a time but do nothing to stop the relentless downward progression of disease.
Lilly’s new drug, like Biogen’s, is a new type of drug called a monoclonal antibody that is designed to modify disease progression, and not just treat symptoms. The drug company says it intends to submit approval of the new drug, called donanemab, to the Food and Drug Administration, the national organization responsible for approving new drugs, by the end of 2021. The company is seeking accelerated approval, which was granted to Biogen for its new drug, Aduhelm.
Both drugs are designed to clear beta-amyloid from the brain. Beta-amyloid, in its toxic form, clumps together to form small aggregates, call oligomers, that later on form amyloid plaques. Some steps in this process is believed to choke off healthy brain cells by disrupting cell-to-cell communication, leaving the telltale memory and thinking impairments of Alzheimer’s disease in its wake.
Eli Lilly’s drug underwent testing in a trial called TRAILBLAZER-ALZ that suggests it slows the progression of Alzheimer’s disease. Patients with Alzheimer’s who received the drug continued to show declines in thinking and memory skills and in the ability to care for themselves. But the declines were slower than in similar patients who received a placebo, similar treatment but without active drug. That mid-stage study, however, was conducted in only 272 patients, a relatively small number for this kind of study.
A more definitive late-stage trial of donanemab in a larger group of patients is underway and currently enrolling patients with early Alzheimer’s disease. But the results of that study are far from clear-cut. Many drugs have shown promise in early-stage trials, only to prove mostly ineffective in late-stage trials in large numbers of patients.
Both donanemab and the newly approved drug Aduhelm are what is known as monoclonal antibodies, a new class of protein drugs that are specially designed to recognize a target — in this case the target is a by-product called beta-amyloid, and it is also known as a hallmark of Alzheimer’s disease.
Other drugs under development target tau, the spaghetti-like proteins that accumulate and form tangles inside neurons as Alzheimer’s progresses. Whether targeting tau or beta-amyloid — or another strategy altogether, or some combination thereof — is the best approach to treating Alzheimer’s disease remains to be determined.
If the FDA approves donanemab for the treatment of Alzheimer’s by the end of the year, the drug could be available to patients by mid-year in 2022. But as the history of Alzheimer’s drug testing has taught us, many hurdles remain.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Eli Lilly, ClinicalTrials.gov