(Bloomberg) -- Makers of two new Alzheimer’s drugs have very different views on a fundamental question: Should patients take their medications long-term?
Japanese drugmaker Eisai Co. presented data Tuesday at the Alzheimer’s Association International Conference in Philadelphia that indicated patients would benefit from taking its Leqembi injection for at least three years. Meanwhile, competitor Eli Lilly & Co. said patients can stop taking its drug, called Kisunla, sooner than that — after levels of the toxic brain protein known as amyloid fall to minimal amounts.
Researchers think amyloid plaques play a central role in Alzheimer’s, and both drugs aim to remove them. The companies behind them are balancing the health effects for sufferers of the debilitating brain disease, who may continue to improve over time if they stay on medications, against cost and time commitments.
Despite costing $26,500 a year, the data Eisai presented bolsters the case for long-term use of its drug. The longer patients are on it, the more effective it appears to be.
“You wouldn’t want to stop treatment, because the disease is progressive and continues even when you clear plaque,” Lynn Kramer, Eisai’s chief clinical officer, said in an interview ahead of the meeting. “The goal is treating the patient, not plaque.”
Mind-Robbing Disease
Developed in partnership with Biogen Inc., Eisai’s Leqembi was the first drug to slow the progression of Alzheimer’s, the mind-robbing disease that afflicts some 6 million Americans. It gained full US approval last year, but uptake has been slow. Last week, European drug regulators rejected the drug due to safety concerns.
Lilly’s Alzheimer’s treatment was cleared in the US earlier this month. With both drugs showing similarly modest benefits, the competition between them may hinge on convenience. Taking patients off Lilly’s drug can reduce the need for caretakers to regularly drive to and from infusion centers for treatments, said John Sims, Lilly’s head of medical for donanemab, also known as Kisunla.
“It can be a burden for a family if you’ve got a working daughter or son who has to do that,” Sims said in an interview.
The diverging views were especially stark when presented at the same conference, and suggest Alzheimer’s treatment will continue to be a point of debate.
Differing Data
During a crowded early-morning session Tuesday that focused on Lilly’s drug, a company official highlighted clinical trial results showing that among patients who stopped taking the drug, amyloid plaque only builds up again very slowly.
The finding “shows persistent benefit and supports limited duration dosing,” said Emily Collins, a senior director of imaging research and development at Lilly, during the presentation. Some two-thirds of patients may have minimal amyloid levels after a year on the drug, making them eligible for discontinuing dosing, she said.
“One way to look at it, is by clearing the plaques you put people into remission for a while,” said Howard Fillit, chief science officer for the Alzheimer’s Drug Discovery Foundation, in an interview after the Lilly presentation.
While the disease process slowly continues, it takes quite awhile for the plaque to build back up to where it was before. He predicted a stop-dosing possibility would prove popular with patients who don’t want to have to keep going into infusion centers.
Meanwhile, a 90-minute session was focused on the evidence supporting longer-term dosing with Eisai’s drug. It included the three-year follow-up data from its big trial, which compared the progression of Alzheimer’s in people taking Leqembi to the natural history of the disease in patients who were untreated. Another presentation earlier in the afternoon noted that stopping Leqembi had “detrimental” effects on various blood tests that correlate with the buildup of toxic protein clumps in the brain of Alzheimer’s patients.
Lilly’s Kisunla also has a potential advantage as it’s infused every four weeks, compared with every two for Leqembi.
Eisai and Biogen are hoping to get regulatory approval for a version of Leqembi that can be administered at home, so families won’t have to travel for treatment. Both drugs have side effects that include brain bleeding and brain swelling.
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