How Leqembi became the biggest news in Alzheimer’s disease in 40 years, and what comes next
Betsy Groves, 73, with her granddaughter. Groves learned in 2021 that she has Alzheimer's disease. She hopes to take Leqembi, a drug approved by the FDA last week.
A few months ago, Betsy Groves traveled less than a mile from her home in Cambridge, Mass. to give a talk to a bunch of scientists. The scientists, who worked for the pharmaceutical companies Biogen and Eisai, wanted to know how she lived her life, how she thought about her future, and what it was like when a doctor’s appointment in 2021 gave her the worst possible news. Groves, 73, has Alzheimer’s disease. She caught it early, through a lumbar puncture that showed evidence of amyloid, an Alzheimer’s hallmark, in her cerebrospinal fluid. As a way of dealing with her diagnosis, she joined the Alzheimer’s Association’s National Early-Stage Advisory Board, which helped her shift into seeing her diagnosis as something she could use to help others.
After her talk, Groves stayed for lunch with the scientists, who were eager to put a face to their work. Biogen and Eisai were about to release the first drug to successfully combat Alzheimer’s in 40 years of experimental disaster. Their drug, which is known by the scientific name lecanemab and the marketing name Leqembi, was granted accelerated approval by the U.S. Food and Drug Administration last Friday, Jan. 6, after a study in 1,800 people showed that it reduced cognitive decline by 27 percent over 18 months.
It is no exaggeration to say that this result is a huge deal. The field of Alzheimer’s drug development has been absolutely littered with failures. Almost everything researchers have tried has tanked in clinical trials. “Most of the things that we've done have proven not to be effective, and it's not because we haven’t been taking a ton of shots at goal,” says Anton Porsteinsson, director of the University of Rochester Alzheimer's Disease Care, Research, and Education Program, who worked on the lecanemab trial. “I think it's fair to say you don't survive in this field unless you're an eternal optimist.”
As far back as 1984, a cure looked like it was within reach: Scientists discovered that the sticky plaques that develop in the brains of those who have Alzheimer’s are made up of a protein fragment called beta-amyloid. Buildup of beta-amyloid seemed to be sufficient to disrupt communication between, and eventually kill, memory cells. If that was true, then the cure should be straightforward: Stop the buildup of beta-amyloid; stop the Alzheimer’s disease.
It wasn’t so simple. Over the next 38 years, hundreds of drugs designed either to interfere with the production of abnormal amyloid or to clear it from the brain flamed out in trials. It got so bad that neuroscience drug divisions at major pharmaceutical companies (AstraZeneca, Pfizer, Bristol-Myers, GSK, Amgen) closed one by one, leaving the field to smaller, scrappier companies, like Cambridge-based Biogen and Tokyo-based Eisai. Some scientists began to dismiss the amyloid hypothesis altogether: If this protein fragment was so important to the disease, why didn’t ridding the brain of it do anything for patients? There was another abnormal protein that showed up in the brains of Alzheimer’s patients, called tau. Some researchers defected to the tau camp, or came to believe the proteins caused damage in combination.
The situation came to a head in 2021, when the FDA granted provisional approval to a drug called aducanumab, marketed as Aduhelm, against the advice of its own advisory council. The approval was based on proof that Aduhelm reduced beta-amyloid in the brain, even though one research trial showed it had no effect on people’s symptoms or daily life. Aduhelm could also cause serious side effects, like brain swelling and amyloid related imaging abnormalities (known as ARIA, these are basically micro-bleeds that appear on MRI scans). Without a clear benefit to memory loss that would make these risks worth it, Medicare refused to pay for Aduhelm among the general population. Two congressional committees launched an investigation into the drug’s approval, citing corporate greed, lapses in protocol, and an unjustifiably high price. (Aduhelm was also produced by the pharmaceutical company Biogen.)
To be clear, Leqembi is not the cure Alzheimer’s researchers hope for. While the drug is the first to show clear signs of a clinical benefit, the scientific establishment is split on how much of a difference Leqembi will make in the real world.
So far, Leqembi is like Aduhelm in that it has been given accelerated approval only for its ability to remove amyloid from the brain. Both are monoclonal antibodies that direct the immune system to attack and clear dysfunctional beta-amyloid. The difference is that, while that’s all Aduhelm was ever shown to do, Leqembi’s makers have already asked the FDA to give it full approval – a decision that would increase the likelihood that Medicare will cover it – based on data that show it also improves Alzheimer’s sufferer’s lives. Leqembi targets a different type of amyloid, a soluble version called “protofibrils,” and that appears to change the effect. “It can give individuals and their families three, six months longer to be participating in daily life and living independently,” says Claire Sexton, PhD, senior director of scientific programs & outreach for the Alzheimer's Association. “These types of changes matter for individuals and for their families.”
To be clear, Leqembi is not the cure Alzheimer’s researchers hope for. It does not halt or reverse the disease, and people do not get better. While the drug is the first to show clear signs of a clinical benefit, the scientific establishment is split on how much of a difference Leqembi will make in the real world. It has “a rather small effect,” wrote NIH Alzheimer’s researcher Madhav Thambisetty, MD, PhD, in an email to Leaps.org. “It is unclear how meaningful this difference will be to patients, and it is unlikely that this level of difference will be obvious to a patient (or their caregivers).” Another issue is cost: Leqembi will become available to patients later this month, but Eisai is setting the price at $26,500 per year, meaning that very few patients will be able to afford it unless Medicare chooses to reimburse them for it.
The same side effects that plagued Aduhelm are common in Leqembi treatment as well. In many patients, amyloid doesn’t just accumulate around neurons, it also forms deposits in the walls of blood vessels. Blood vessels that are shot through with amyloid are more brittle. If you infuse a drug that targets amyloid, brittle blood vessels in the brain can develop leakage that results in swelling or bleeds. Most of these come with no symptoms, and are only seen during testing, which is why they are called “imaging abnormalities.” But in situations where patients have multiple diseases or are prescribed incompatible drugs, they can be serious enough to cause death. The three deaths reported from Leqembi treatment (so far) are enough to make Thambisetty wonder “how well the drug may be tolerated in real world clinical practice where patients are likely to be sicker and have multiple other medical conditions in contrast to carefully selected patients in clinical trials.”
Porsteinsson believes that earlier detection of Alzheimer’s disease will be the next great advance in treatment, a more important step forward than Leqembi’s approval.
Still, there are reasons to be excited. A successful Alzheimer’s drug can pave the way for combination studies, in which patients try a known effective drug alongside newer, more experimental ones; or preventative studies, which take place years before symptoms occur. It also represents enormous strides in researchers’ understanding of the disease. For example, drug dosages have increased massively—in some cases quadrupling—from the early days of Alzheimer’s research. And patient selection for studies has changed drastically as well. Doctors now know that you’ve got to catch the disease early, through PET-scans or CSF tests for amyloid, if you want any chance of changing its course.
Porsteinsson believes that earlier detection of Alzheimer’s disease will be the next great advance in treatment, a more important step forward than Leqembi’s approval. His lab already uses blood tests for different types of amyloid, for different types of tau, and for measures of neuroinflammation, neural damage, and synaptic health, but commercially available versions from companies like C2N, Quest, and Fuji Rebio are likely to hit the market in the next couple of years. “[They are] going to transform the diagnosis of Alzheimer's disease,” Porsteinsson says. “If someone is experiencing memory problems, their physicians will be able to order a blood test that will tell us if this is the result of changes in your brain due to Alzheimer's disease. It will ultimately make it much easier to identify people at a very early stage of the disease, where they are most likely to benefit from treatment.”
Learn more about new blood tests to detect Alzheimer's
Early detection can help patients for more philosophical reasons as well. Betsy Groves credits finding her Alzheimer’s early with giving her the space to understand and process the changes that were happening to her before they got so bad that she couldn’t. She has been able to update her legal documents and, through her role on the Advisory Group, help the Alzheimer’s Association with developing its programs and support services for people in the early stages of the disease. She still drives, and because she and her husband love to travel, they are hoping to get out of grey, rainy Cambridge and off to Texas or Arizona this spring.
Because her Alzheimer’s disease involves amyloid deposits (a “substantial portion” do not, says Claire Sexton, which is an additional complication for research), and has not yet reached an advanced stage, Groves may be a good candidate to try Leqembi. She says she’d welcome the opportunity to take it. If she can get access, Groves hopes the drug will give her more days to be fully functioning with her husband, daughters, and three grandchildren. Mostly, she avoids thinking about what the latter stages of Alzheimer’s might be like, but she knows the time will come when it will be her reality. “So whatever lecanemab can do to extend my more productive ways of engaging with relationships in the world,” she says. “I'll take that in a minute.”
Vaccine passports, if required by businesses and universities, may give people a false sense of security, one expert cautions.
Vaccines are one of the greatest public health accomplishments of all time. For centuries, public health has relied on vaccinations to prevent and control disease outbreaks for a plethora of infectious scourges, with our crowning achievement being the successful eradication of smallpox.
The purpose of vaccine documentation is to provide proof of an individual's protection from either becoming infected or transmitting a vaccine-preventable disease. Vouching for these protections requires a firm knowledge about the epidemiology of the disease, as well as scientific knowledge concerning the efficacy of the vaccine. The vaccines we currently require be documented have met these tests; the vaccine for COVID-19 has not yet been proven to do so.
Let's acknowledge that the term "vaccine passport" is a poor choice of words. Passports are a legal travel document created by nations and governed by law for identification of the bearer to control entry and exit from nation states. They often serve as legal forms of identification and as a record of international travel. They are generally very sophisticated documents that have been created in a secure manner and may include a range of electronic and, in some cases, biometric measures such as fingerprints to ensure the holder is indeed who they say they are. Vaccine passports are medical documents used to document the vaccination status of an individual. They do not undergo the same level of administrative scrutiny and cannot be used to verify that the presenter is indeed the vaccinated individual. Some companies do have electronic methods to address concerns about verification; however, most people currently have paper records that can be easily falsified.
"Vaccine passports" as currently proposed risk giving people a false sense of security.
Successful disease control from vaccination programs relies on the ability to vaccinate at a level that prevents large-scale disease spread and the ability to rapidly identify the presence of disease outbreaks. It requires reliable, safe, and effective vaccines that are easily delivered in clinical and nonclinical settings. Keeping vaccination information as a part of the medical record, and even having a separate specialized vaccine record for personal use, is a time-honored tradition.
Keeping a vaccination record provides a method to keep track of the many shots one receives and serves as a visual reminder to help ensure the appropriate vaccine shot schedule is maintained for vaccines requiring multiple doses. The vaccine record, when combined with vaccine safety monitoring systems, serves as a mechanism to track adverse events to monitor and ensure the safety of vaccines as a consumer product. The record also serves as the official record of vaccination when required for administrative or legally prescribed purposes.
"Vaccine passports" as currently proposed risk giving people a false sense of security. In the case of the COVID-19 vaccines currently approved for use, many of the essential questions remain unanswered. While we do know the current three vaccines are highly protective against severe disease and death, and there is some evidence that these vaccinations do reduce infections and virus transmission of SARS-CoV-2, we do not yet know the full degree to which this occurs.
For example, we know there have been some cases of people that have been infected in close proximity to getting their full vaccination and rare cases of breakthrough reinfections. A breakthrough infection in a restaurant is a challenge for contact tracing, but an outbreak from a movie theater exposure or a baseball game could spark a major outbreak at our current level of vaccination. Current CDC guidance recommends continued mask wearing in order to address these concerns.
We also do not yet know how long the protections will last and if or when a booster or revaccination is required. In effect, it is too soon to know. Should an annual booster shot be required, then a vaccine passport would require annual updating, a process more frequent than renewal of a driver's license.
We also know that the current SARS-CoV-2 virus is mutating briskly. While the current approved vaccines have remained effective overall, there is evidence of some degree of degradation in vaccine effectiveness against some of the circulating strains. We also have sparse data on many of the other emerging strains of concern because we have not had the surveillance capacity in the U.S. to gain an adequate sense of how the virus is changing to fully align vaccine effectiveness with viral capabilities.
The risk of people misusing these "passports" is troubling. The potential for using these documents for hiring, firing or job limitation is a serious concern. Unvaccinated workers are at risk of this form of discrimination even from well-meaning employers or supervisors. Health insurers are prohibited by the Affordable Care Act from discriminating based on preexisting conditions, but they could probably charge a higher premium for unvaccinated individuals. There also is a risk of stigmatizing individuals who are not vaccinated or have left their vaccine documentation at home. Another concern: the opportunity to discriminate based on race, gender, sexual orientation, or religion, using one's vaccination status as an excuse.
These "passports" are being discussed as a "ticket verification" for entry to many activities, including dining at restaurants, flying domestically and/or internationally, going to movie theaters and sporting events, etc. These are all activities we already are doing at reduced levels and for which wearing a mask, hand hygiene and physical distancing are effective disease control practices. COVID-19 vaccines are indeed the measure that will make the ability to totally reopen our society complete, but we are not there yet. Documentation of one's COVID-19 vaccine status may be useful in selected situations in the future. That remains to be seen.
Finally, inadequate vaccine supply and disparities in vaccine delivery have created enormous challenges in providing equal access to vaccination. Also, the amount of misinformation, disinformation, and lingering vaccine hesitancy continue to limit the speed at which we will reach the level of vaccination of the population that would make this documentation meaningful. The requirement for "vaccine passports" is already alienating people who are opposed to vaccinations for a variety of reasons, paradoxically risking reduced vaccine uptake. This politicization of the vaccination effort is of concern. There are indeed people who, due to medical contraindications or legal exemptions, will not be vaccinated, and we do not yet have a national framework on how to address this.
Vaccine passports are not the solution for reopening our society — a robust vaccination program is. The requirement to document one's vaccination status for COVID-19 may one day have its place. For now, it is an idea whose time has not yet come.
Editor's Note: This op/ed is part of a "Big Question" series on the ethics of vaccine passports. Read the flip side argument here.
A digital health passport required by businesses and universities could help us get back to normal more quickly, one expert argues.
"Vaccine passports" are a system that requires proof of a COVID-19 vaccination as a condition of engaging in activities that pose a risk of transmitted SARS-CoV-2. Digital Health Passes (DHPs) are typically a smartphone application with a code that verifies whether someone has been vaccinated.
Vaccine passports could very much be in our future. Many businesses are implementing or planning to require proof of vaccination as a condition of returning to the workplace. Colleges and universities have announced vaccine requirements for students, staff, and faculty. It may not be long before the private sector requires a vaccination card or image to attend an entertainment or sporting event, to travel, or even to dine or shop indoors, at least in some venues.
But it's unlikely the federal government or the states will launch DHPs, at least not in the near-term. President Biden announced the White House has no intention of requiring proof of vaccination. While no state has mandated DHPs, New York is piloting its Excelsior Pass on a voluntary basis, partnering with IBM. Other nations are not so hesitant. Israel's "Green Pass" has gotten the nation back to normal in record time. And various countries and regions are planning DHPs, including the European Union and the United Kingdom. Foreign airlines are likely to require proof of vaccination as a condition of flying internationally.
DHPs could emerge as a way to get us back to normal more quickly, but are they ethical? Let's start with the law. The US Equal Opportunity Commission (EEOC) has specifically said that employers have the legal right to require proof of vaccination as a condition of returning to work. Colleges and universities already require several vaccines for students living in dorms. Hospitals and nursing homes often mandate influenza vaccinations. And, of course, all states require childhood vaccinations for school attendance. Vaccine passports are lawful but are they ethical? The short answer is "yes" but only if we ensure no one is left behind.
Vaccine passports "don't force anyone to be vaccinated against his or her will. They simply say to individuals that if you choose not to be vaccinated, you can't work or recreate in public spaces that risk transmission of the virus."
Why are vaccine passports ethical? Vaccines are a miracle of modern science, but they have become a political symbol, and a significant part of the population doesn't want to get a jab. The rare cases of blood clots associated with the Johnson & Johnson and AstraZeneca vaccines have only created more distrust.
Most opposition to vaccine passports hinges on the claim that they infringe personal autonomy and liberty. But this argument misses the point. Of course, every competent adult has the right to make decisions that affect his or her own health and safety. But no one has a right to infringe on the rights of others, such as by exposing them to a potentially serious or deadly infectious disease. An individual can't claim the right to attend a crowded event mask-less and unvaccinated. This was once accepted across the political spectrum. Conservative economists called it an "externality," that is a person has no right to harm others. The U.S. has lost the tradition of the common good. We have become so focused on our own individual rights that we forget about our ethical obligations to our neighbors and to our community.
In fact, DHPs actually don't force anyone to be vaccinated against his or her will. They simply say to individuals that if you choose not to be vaccinated, you can't work or recreate in public spaces that risk transmission of the virus.
DHPs also don't infringe on privacy. Again, everyone has the choice whether to show proof of vaccination. It isn't required. Moreover, DHPs may actually protect privacy because all they do is show whether or not you have been vaccinated. They don't disclose any other personal medical information. All of us actually have already had to show proof of vaccination as a condition of going to school. Thus, DHPs are well established in the United States.
But there is one ethical argument against DHPs that I find to be powerful, and that is equity. If we require proof of vaccination while doses are scarce, we will give the already privileged even more privilege. And that would be unconscionable. Thus, DHPs should not be implemented until everyone who wants a vaccine is able to get a vaccine. Equity isn't a side issue. It needs to be front and center.
As of today, all adults in the U.S. are eligible to get vaccinated, and President Biden has pledged that by the end of May there will be enough doses to vaccinate the entire U.S. population. It is a realistic promise. Once vaccines become plentiful, everyone should get their shot. All Food and Drug Administration authorized vaccines are highly safe and effective, even the Johnson & Johnson vaccine that the FDA has just put on pause.
Businesses have an economic incentive to require proof of vaccination. Very few of us would feel comfortable returning to our jobs, shops, theaters, or restaurants unless we feel safe. Businesses understand the duty to create safer places for work, recreation, and commerce.
One question has dominated national conversation since the pandemic began. "When will we get back to normal?" There is a deep human yearning to hug family and friends, see our work colleagues, recreate, and be entertained. One day we will have defeated this wily virus and get back to normal. But vaccine passports can help us get back to the things we love faster and more safely. As long as we don't leave anyone behind, using this miracle of modern science to make our lives better is both lawful and ethical.
Editor's Note: This op/ed is part of a "Big Question" series on the ethics of vaccine passports. Read the flip-side argument here.