Biogen and Eisai reported the finding from a large late-stage clinical trial of lecanemab, a drug they are developing.The pharmaceutical companies Biogen and Eisai said on Tuesday that a drug they are developing for Alzheimer’s disease had slowed the rate of cognitive decline in a large late-stage clinical trial.The strong results boost the drug’s chances of winning approval and offer renewed hope for a class of Alzheimer’s drugs that have repeatedly failed or generated mixed results.The positive data also offer Biogen a second chance after the company’s disastrous rollout of another Alzheimer’s drug, Aduhelm. That medication won regulatory approval last year despite little evidence that it could slow cognitive decline, received only sharply limited coverage by Medicare and has proved to be a commercial failure.The results appear stronger for the new medication, lecanemab. Cognitive decline in the group of volunteers who received lecanemab was reduced by 27 percent compared with the group who received a placebo in the clinical trial, which enrolled nearly 1,800 participants with mild cognitive impairment or mild Alzheimer’s disease, the companies said.The trial of lecanemab, which is administered via intravenous infusion, was the largest to date to test whether clearing the brain of plaques formed by the accumulation of a protein called amyloid could slow the progression of Alzheimer’s disease. Aduhelm is designed to work in a similar way.As with previous anti-amyloid drugs, some patients taking lecanemab experienced brain swelling or brain bleeding, but the prevalence of these side effects was lower than with Aduhelm and other experimental medications.Eisai had already applied for accelerated approval, the type of approval given to Aduhelm. The process allows the Food and Drug Administration to greenlight drugs if they have uncertain evidence of benefit but affect a disease’s biological pathway in a way that is considered reasonably likely to benefit patients. The company said on Tuesday night that it would first continue with the accelerated approval process, with an F.D.A. decision expected by early January, and then use the newer data to seek full approval. (Accelerated approval requires companies to do further trials and prove that their drug works.)Analysts predict that lecanemab, or any effective Alzheimer’s medication, would most likely be a multibillion-dollar blockbuster.“For Biogen, it puts them back in the Alzheimer’s game,” Brian Skorney, an analyst at the investment bank Baird, said.In a briefing for reporters Tuesday night, Ivan Cheung, the chairman and chief executive of Eisai, said the results represented “the first definitively positive large clinical trial to show that you can indeed slow down Alzheimer’s disease at this very early symptomatic stage.”He said that the drug started to show a benefit to patients about six months after they began taking it and that the benefit increased until the trial ended, 18 months after patients started on the drug.The companies plan to present more detailed results in November.Some experts said the drug’s ability to slow cognitive decline — by 0.45 on an 18-point scale — was modest at best and might not be a difference that patients in the mild early stages of the disease would notice.Dr. Lon Schneider, director of the California Alzheimer’s Disease Center at the University of Southern California, said the effect “is small and would not be considered by many as a minimally clinically important difference.” However, he added, “others would strongly disagree and say it’s clinically meaningful.”Dr. Schneider said the “relatively low” rates of brain swelling and bleeding “suggest that lecanemab is easier to use” than Aduhelm.He added that “although taking a press release at face value, which is often a chancy thing to do without having real data or reports, it seems that lecanemab would most likely receive regular marketing approval based on this one study alone.”In the briefing, Mr. Cheung said the company considered the results “very clinically meaningful,” but he added, “Of course, there are different opinions out there on defining what clinical meaningfulness is for this stage of disease.”Other companies are also developing treatments that could shake up the market for Alzheimer’s drugs, which before Aduhelm had not seen a novel treatment for two decades. Before the end of this year, Roche is expected to report data from two studies of a drug known as gantenerumab. The F.D.A. is expected to make a decision on whether to grant accelerated approval to an Alzheimer’s drug from Eli Lilly known as donanemab by early January, with results from a larger study of that drug due in the middle of next year.The results from the study on lecanemab “set a high bar that I think will be hard for the other drugs, if they are successful, to beat,” Mr. Skorney said.

The agency faced criticism for approving Aduhelm for all Alzheimer’s patients. Now it recommends that the drug be given only to those with mild symptoms.Under fire for approving a questionable drug for all Alzheimer’s patients, the Food and Drug Administration on Thursday greatly narrowed its previous recommendation and is now suggesting that only those with mild memory or thinking problems should receive it.The reversal, highly unusual for a drug that has been available for only a few weeks, is likely to reduce the approximate number of Americans who are eligible for the treatment to 1.5 million from six million.The approval of Aduhelm early last month was one of the most contentious F.D.A. decisions in years. Groups that represent Alzheimer’s patients had intensely lobbied the agency to sign off on the first new drug to treat the disease in 18 years — and the first ever designed to attack its biological underpinnings.But many scientists, as well as the F.D.A.’s independent advisory committee, said there was not convincing evidence that the drug worked.In addition, the agency’s recommendation that Aduhelm be available to all Alzheimer’s patients, not just those showing early symptoms, stirred up even more concern among medical experts, including those who had supported the drug’s approval.After the approval, three members of the advisory committee resigned in protest. One, Dr. Aaron Kesselheim, described it as “the worst approval decision” that he could remember.The drug’s maker, Biogen, said last month that it would charge $56,000 annually for the drug. Associated costs — such as for diagnostics and safety monitoring, since the drug’s side effects include brain swelling and bleeding — could add tens of thousands of dollars to each patient’s annual bill..css-1xzcza9{list-style-type:disc;padding-inline-start:1em;}.css-3btd0c{font-family:nyt-franklin,helvetica,arial,sans-serif;font-size:1rem;line-height:1.375rem;color:#333;margin-bottom:0.78125rem;}@media (min-width:740px){.css-3btd0c{font-size:1.0625rem;line-height:1.5rem;margin-bottom:0.9375rem;}}.css-3btd0c strong{font-weight:600;}.css-3btd0c em{font-style:italic;}.css-w739ur{margin:0 auto 5px;font-family:nyt-franklin,helvetica,arial,sans-serif;font-weight:700;font-size:1.125rem;line-height:1.3125rem;color:#121212;}#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-family:nyt-cheltenham,georgia,’times new roman’,times,serif;font-weight:700;font-size:1.375rem;line-height:1.625rem;}@media (min-width:740px){#NYT_BELOW_MAIN_CONTENT_REGION .css-w739ur{font-size:1.6875rem;line-height:1.875rem;}}@media (min-width:740px){.css-w739ur{font-size:1.25rem;line-height:1.4375rem;}}.css-9s9ecg{margin-bottom:15px;}.css-uf1ume{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-box-pack:justify;-webkit-justify-content:space-between;-ms-flex-pack:justify;justify-content:space-between;}.css-wxi1cx{display:-webkit-box;display:-webkit-flex;display:-ms-flexbox;display:flex;-webkit-flex-direction:column;-ms-flex-direction:column;flex-direction:column;-webkit-align-self:flex-end;-ms-flex-item-align:end;align-self:flex-end;}.css-12vbvwq{background-color:white;border:1px solid #e2e2e2;width:calc(100% – 40px);max-width:600px;margin:1.5rem auto 1.9rem;padding:15px;box-sizing:border-box;}@media (min-width:740px){.css-12vbvwq{padding:20px;width:100%;}}.css-12vbvwq:focus{outline:1px solid #e2e2e2;}#NYT_BELOW_MAIN_CONTENT_REGION .css-12vbvwq{border:none;padding:10px 0 0;border-top:2px solid #121212;}.css-12vbvwq[data-truncated] .css-rdoyk0{-webkit-transform:rotate(0deg);-ms-transform:rotate(0deg);transform:rotate(0deg);}.css-12vbvwq[data-truncated] .css-eb027h{max-height:300px;overflow:hidden;-webkit-transition:none;transition:none;}.css-12vbvwq[data-truncated] .css-5gimkt:after{content:’See more’;}.css-12vbvwq[data-truncated] .css-6mllg9{opacity:1;}.css-qjk116{margin:0 auto;overflow:hidden;}.css-qjk116 strong{font-weight:700;}.css-qjk116 em{font-style:italic;}.css-qjk116 a{color:#326891;-webkit-text-decoration:underline;text-decoration:underline;text-underline-offset:1px;-webkit-text-decoration-thickness:1px;text-decoration-thickness:1px;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:visited{color:#326891;-webkit-text-decoration-color:#326891;text-decoration-color:#326891;}.css-qjk116 a:hover{-webkit-text-decoration:none;text-decoration:none;}Analysts expected that the drug’s widespread use would strain Medicare’s budget. By one estimate, it could leave taxpayers on the hook for $29 billion in new spending, more than the annual budget of the National Aeronautics and Space Administration.The new guidance does not prevent doctors from prescribing Aduhelm to patients with moderate or severe Alzheimer’s. But the about-face sends a strong message to doctors and insurers about who should receive the drug.It also substantially increases the odds that Medicare and private insurers will restrict coverage of the drug, which is given as a monthly intravenous infusion. That would mean that patients with moderate or severe Alzheimer’s would have to pay the five-figure annual costs out of their own pockets, which experts regard as unlikely to happen frequently.Michael Felberbaum, a spokesman for the F.D.A., said the agency had changed its recommendation after “confusion regarding the intended population for treatment.”Dr. Al Sandrock, Biogen’s head of research and development, said in a statement that the company was “committed to continue to listen to the community’s needs” regarding Aduhelm. Biogen’s stock has soared 29 percent since the drug was approved on June 7.When Biogen conducted clinical trials of Aduhelm, it included only people with early symptoms of cognitive decline. The drug appeared slightly effective, at best.In one late-stage trial, the highest dose of the drug appeared to slow patients’ cognitive decline by a fraction of a point on an 18-point scale that assesses their memory, problem-solving skills and function. But in an identically designed second clinical trial, the drug showed no benefit at all.The drug’s initial label said it could be appropriate for anyone with Alzheimer’s, encompassing about six million Americans. Under the revised label, about 1.5 million are likely to be eligible.Biogen, via Associated PressThe F.D.A. signed off on the drug under a framework known as accelerated approval. That allows drugs that have not yet shown they can help patients to be approved if they have a substantial effect on a biomarker of a disease.The agency acknowledged last month that there was not convincing evidence that Aduhelm slowed patients’ cognitive decline. Instead, it based its approval on the drug’s ability to reduce levels of a protein called amyloid, which clumps into plaques in the brains of Alzheimer’s patients.But many Alzheimer’s experts have said there is not solid evidence that reducing amyloid levels has any effect on people’s cognitive problems.At a forum last month sponsored by the Alzheimer’s Association, which had pushed for approval of Aduhelm, a panel of clinicians with varying views of whether the drug should have been approved were united in saying its use should be limited. The consensus was that Aduhelm should be only for patients in mild stages of the disease whose brains have high levels of amyloid and who don’t have medical conditions that could make them vulnerable to Aduhelm’s potentially dangerous side effects.On Thursday, Dr. Lon Schneider, director of the California Alzheimer’s Disease Center at the University of Southern California, said the F.D.A. should further narrow its guidelines — which are listed on the drug’s label — for who is eligible for the drug.Dr. Schneider, who worked on one of the clinical trials of Aduhelm and opposed its approval, said the trials had excluded people with diabetes and high blood pressure and those taking blood thinners. As a result, “we don’t know any extent of increased risk” for those patients, he said, adding that the drug’s label should include warnings about treating those patients with Aduhelm.The F.D.A. is being run by an interim commissioner, Dr. Janet Woodcock, because President Biden has not nominated a permanent leader. Before becoming interim commissioner in January, Dr. Woodcock was the longtime leader of the arm of the agency responsible for approving drugs. Officials said she was not involved in the Aduhelm decision, though she has defended it as “very solid.”Some experts said the F.D.A.’s quick reversal was a sign that it had mishandled its initial review and was now ending up closer to where it should have started.“The revision of this label is yet another piece of evidence that should cause the American public to be concerned about how F.D.A. is practicing its regulatory science,” said Dr. Jason Karlawish, a co-director of the University of Pennsylvania’s Penn Memory Center.The fallout from the initial approval of the drug is still spreading.In Congress, two House committees last month announced an investigation into Aduhelm’s approval and price. Senators from both parties have called for an investigation in that chamber, too.Researchers said such outside scrutiny was important because of the controversy swirling around the drug and the F.D.A.’s decision-making. “This event only adds to the importance of having those congressional hearings to figure out what’s going on at F.D.A. and why they’re doing this,” Dr. Karlawish said.Some analysts said the narrower eligibility for the drug could help Biogen deflect criticism from lawmakers. “This helps their case to say, ‘Hey, we’re not just completely pushing boundaries as hard as we can,’” said Brian Skorney, an analyst at Robert W. Baird & Company. He said he expected Aduhelm to generate $7.5 billion in revenue for Biogen in 2025.Biogen has not yet announced how many patients have received the drug, but its distribution is expected to be slow in the first months because of challenges administering it.The F.D.A.’s narrowed guidance only applies to when people start taking the drug. Mr. Felberbaum, the spokesman, said some patients on Aduhelm whose symptoms grow more severe “may benefit from ongoing treatment.”The caveat is that there is no scientific evidence that Aduhelm will help such people.

Despite scant evidence that it works, the drug, Aduhelm, is predicted to generate billions of dollars in revenue, much of it from Medicare.The Food and Drug Administration’s decision on Monday to approve a new Alzheimer’s medication over the fierce objections of its scientific advisers sets into motion one of the most controversial drug introductions in years.For its manufacturer, Biogen, the new drug is poised to be a blockbuster. For just about everyone else, it is likely to further inflate high U.S. health care costs.And that is despite the fact that there is not much evidence the drug actually works.More than six million Americans have Alzheimer’s and will be eligible to take the drug, which will be sold under the brand name Aduhelm and must be given as a monthly intravenous infusion. Biogen said it would charge an average of $56,000 a year per patient. There will probably be tens of thousands of dollars in additional costs for screening and monitoring patients.The drug is all but certain to unleash a gusher of profits for Biogen — the drug is expected to become one of the best-selling pharmaceutical products in the world within a few years — as well as for the hundreds of clinics expected to administer the drug.Those billions of dollars in anticipated costs are likely to be shouldered largely by Medicare.The drug’s approval could drive up insurance premiums, according to health care policy experts. And it could add new out-of-pocket costs for some families that are already facing years of staggering costs for caring for loved ones with Alzheimer’s.“This is really what keeps me up at night: A therapy of this cost is going to have enormous implications for everyone,” said Dr. Joseph Ross, a pharmaceutical policy expert at Yale who sits on a committee that advises Medicare on some coverage decisions. “And by everyone, I literally mean you, too. There’s going to be some 60- and 70-year-olds on your plan. If they start getting this treatment, you will see your premiums will go up.”Biogen has said it expects more than 600 sites across the country to soon be ready to administer the drug. But experts predict that demand, including from patients who have not previously sought care for their cognitive problems, will outpace the supply of trained specialists, scanning machines and chairs in which patients receive infusions.“I don’t think we’ll be ready on Day 1 by any stretch. It’s going to be a learning curve,” said Dr. Erik Musiek, who sees Alzheimer’s patients at the memory clinic at Washington University in St. Louis, where new patients already have to wait up to six months for appointments.Aduhelm is a monoclonal antibody that targets a protein in the brain that clumps into plaques in people with Alzheimer’s. It is the first new Alzheimer’s treatment since 2003 and the first ever approved to attack the biological underpinnings of the disease, instead of merely postponing symptoms.“It’s going to be a learning curve,” said Dr. Erik Musiek, who sees Alzheimer’s patients at a memory clinic in St. Louis.Nick Schnelle for The New York TimesBut there is not strong evidence that the drug helps patients, and it comes with potentially serious side effects. Prominent experts, including the F.D.A.’s independent advisory committee and a professional society representing geriatricians and other health care providers for older adults, urged the agency not to approve the drug.“It’s completely unconvincing that we should be using it at all,” said Dr. Peter Bach, a drug pricing expert at Memorial Sloan Kettering Cancer Center. “In reality, we shouldn’t be paying anything. We should be continuing to research until we have drugs that are shown to be effective.”Biogen’s $56,000 price tag is higher than many Wall Street analysts had expected. The company’s shares soared 38 percent on Monday.The Institute for Clinical and Economic Review, which evaluates the value of medicines, has estimated that Biogen’s drug would be cost-effective only below $8,300.The drug’s sales are expected to pick up slowly in its first months of availability, because of the challenges around administering it and because patients start out on a lower, less expensive dose.But even if only a small fraction of people with Alzheimer’s begin taking the drug, it will be enormously lucrative. Analysts at Cowen said on Monday that they expected the drug to reach 8 percent of Americans with mild Alzheimer’s by 2025, yielding $7 billion in revenue.In addition to the United States, Biogen has asked regulators in Australia, Brazil, Canada, the European Union, Japan and Switzerland to review the drug.The U.S. approval is a crucial victory for a company that has been counting on Aduhelm to make up for stalled or declining revenue from its other products. Competitors last year introduced generic versions of Biogen’s multiple sclerosis drug, Tecfidera, causing the company to miss out on hundreds of millions of dollars in revenue from what had been its top-selling product.The approval “completely transforms” Biogen, said Brian Skorney, an analyst at Robert W. Baird & Company, who is projecting that the drug will generate $7.5 billion in revenue in 2025. “This changes it from a declining revenue company to a growth company,” he said, and, in so doing, “opens up a bit of Pandora’s box” in terms of pricing and reimbursement.While only patients with mild cognitive decline were enrolled in the clinical trials, the F.D.A. approved the drug for anyone with Alzheimer’s, a much broader group of patients than many experts were expecting.Just how lucrative the drug will be for Biogen will depend on how many patients it can reach — and in what circumstances, and for how long, insurers are willing to pay for it.Dr. Steve Miller, the chief clinical officer at the insurer Cigna, said on Monday that he expected his company and most of its peers would pay for the drug only for patients with mild cognitive symptoms and higher-than-normal levels of the protein amyloid in their brains.“There’s just no data that more advanced patients will benefit,” he said.Dr. Miller said he was disappointed that the F.D.A. had made so many patients eligible. “You’re leaving the tough decision-making about who should be covered to the individual payers,” he said.The most important payer will most likely be Medicare’s Part B program, which covers drugs that are administered to seniors in doctors’ offices and other outpatient settings.A spokeswoman for the Centers for Medicare and Medicaid Services said last month that the agency would provide more information in the future if the F.D.A. approved Biogen’s drug. The agency “understands that it is vitally important for our beneficiaries to have access to the latest therapies and wants to ensure that Medicare pays for these treatments appropriately,” the spokeswoman said.Biogen expects the new Alzheimer’s drug to cost about $56,000 a year per patient.CJ Gunther/EPA, via ShutterstockIf Medicare covers the drug, it will very likely become the Part B program’s most costly medication within a few years. In 2019, the Part B program’s biggest drug expenditure, at $2.9 billion, was for Eylea, which treats macular degeneration, followed by $2.7 billion for the cancer drug Keytruda.The program does not generally pay for the PET scans that were used in clinical trials to detect whether patients had amyloid in their brains. While the F.D.A. is not requiring them, such scans are expected to be widely used to help screen patients who might take the drug. Spinal taps, a procedure in which a needle is inserted into the lower back to collect fluid, may also be used in some cases.Insurers also might balk at paying for some associated costs. Those include regular M.R.I. scans to monitor for potential side effects, like brain swelling or bleeding that occurred in 40 percent of clinical trial participants. These effects, while often mild, can be serious.Dr. Miller of Cigna said such additional costs could come to about $30,000 per patient in the first year of treatment, plus about half that each subsequent year.To the extent that those additional costs are covered by insurance, they would probably be a financial boon for so-called memory clinics that see patients with dementia.Such clinics, typically part of larger health systems or medical centers, have historically struggled to make money because of the nature of their services, such as cognitive testing, caregiver support and education. They often rely on research funding and philanthropy to make up for shortfalls in clinical revenue.Money-generating procedures like M.R.I. scans could change that. “People will start expanding their clinics if there’s money to be made,” said Dr. Musiek of Washington University.In the short term, though, the anticipated demand for the new drug is likely to produce logistical headaches and delays.In Las Vegas, the Cleveland Clinic’s Lou Ruvo Center for Brain Health is projecting that nearly 800 people, or more than half of the patients in its cognitive disorders program, might be screened to get the drug. But the center has just six infusion chairs and one PET scanning machine, which can handle two or three patients a day.“We don’t have probably enough diagnostic capacity at this point, and we don’t have enough infusion chairs, and we don’t have a fast way to get a diagnosis,” said Dr. Aaron Ritter, a neuropsychiatrist at the center. “We have to change the entire way that we would deliver care.”