Switzerland’s bitter-sweet news for Alzheimer’s patients

The latest Alzheimer's drugs are viewed as breakthroughs but they aren't able to halt the disease. Keystone

Swiss medicines regulator Swissmedic was expected to approve two drugs for Alzheimer‘s disease. But in late January it only approved one, leaving patients in Switzerland with fewer treatment options than in many countries. What happened?

For two and a half years, doctors in Switzerland have been eagerly awaiting a decision from Swissmedic on two new drugs for early-stage Alzheimer’s disease – Leqembi (lecanemab) and Kisunla (donanemab).

These are the first drugs to slow cognitive decline and address one potential underlying cause of the disease – amyloid plaques in the brain. Leqembi garnered more media attention as it was approved by the US regulator in July 2023 – a year before Kisunla.

Since then, more than 50 countriesExternal link have approved it. Both drugs were submitted to Swissmedic for approval within six months of each other in 2023.

News finally arrived in early February that Swissmedic had authorised Kisunla, Eli Lilly’s treatment for early-stage Alzheimer’s disease, on January 22, 2026. As for Leqembi, the Japanese manufacturer Eisai withdrew its application for authorisation on January 29, according to the Swissmedic journalExternal link.

“The approval of Kisunla is positive news. At least one of the US-approved treatments is coming to Switzerland,” Bogdan Draganski, a clinical neuroscientist who heads the Memory Clinic at Bern’s largest hospital, Inselspital, told Swissinfo. “But of course it would have been nice to have both treatments. The more choice the better.”

Alzheimer’s afflictsExternal link some 32 million people worldwide. With population ageing, the number is expected to triple by 2050. It is estimated that about 161,000 peopleExternal link are living with dementia in Switzerland, with Alzheimer’s disease being the most common form, accounting for 60-70% of cases.

Why Eisai took the drastic decision to pull Leqembi’s approval application isn’t entirely clear nor what it means for patients. In an email to Swissinfo, a company spokesperson explained that it didn’t agree with the “restrictive” conditions under which the regulator was willing to grant authorisation, which would have led to a “substantially smaller eligible patient population in Switzerland” than in the rest of Europe.

“After careful consideration,” wrote a spokesperson, “withdrawal of the application was the only feasible path forward under these conditions”.

The disappointing outcome for doctors and patients in Switzerland underscores the difficult choice facing regulators when assessing the latest Alzheimer’s treatments.

Both Leqembi and Kisunla are widely seen as breakthroughs in a field that has struggled to produce any new treatments in decades, despite billions in investment. Both drugs have shown to slow cognitive decline and clear amyloid plaques in the brain. But they aren’t cures and come with serious potential side effects.

Weighing the benefits and risks

The heart of the disagreement between Eisai and Swissmedic appears to be how they view Leqembi’s benefits and risks in specific patient populations. Regulators approve drugs by evaluating if clinical trial data demonstrates that a drug’s benefits outweigh its risks for the intended population.

Experts widely agree that both drugs offer modest benefits. In the pivotal clinical trialExternal link published in 2023, Leqembi slowed cognitive decline in people with early-stage Alzheimer’s disease by 27% compared with a placebo. Kisunla slowed cognitive decline by up to 35% in its key clinical trial. According to some expertsExternal link, this could keep dementia at bay for only 4-8 months.

Both drugs also carry risks of amyloid-related imaging abnormalities (ARIA) – a life-threatening form of brain swelling and bleeding. Kisunla had a higher reported ARIA incidence compared to Leqembi in clinical trials. However, the benefits and risks are difficult to compare because of different trial designs.

In both cases, people who carry the APOE4 gene variant – the strongest knownExternal link genetic risk factor for late-stage Alzheimer’s – are at increased risk of ARIA. People with two copies of the gene are at a higher risk than people with one copy.

According to Eisai, Swissmedic’s assessment concluded Leqembi should only be approved for people who don’t carry any copies of the APOE4 gene variant. This is more restrictive than in Europe where the regulator approved it for patients with one or no copy of the gene variant.

Amyloid mystery

One of the key features of Alzheimer’s disease is the abnormal accumulations of two proteins in the brain: amyloid, which starts clumping into plaques at least 20 years before symptoms emerge, and tau, which forms tangles after amyloid accumulate. However, some people have significant amyloid plaque buildup in their brains but never develop cognitive symptoms of Alzheimer’s disease. Researchers are trying to understand why amyloid accumulates, how it causes damage, its precise relationship with tau, and its relative contribution to Alzheimer’s.

In its approval decision for Kisunla, Swissmedic restricted the patient population to a lesser extent than Leqembi. It is authorised for people with no or one copy of the APOE4 variant. Why the regulator may have chosen different restrictions for the two drugs is unclear.

Studies showExternal link that globally some 40-65% of all Alzheimer’s disease patients carry at least one APOE4 variant. It’s difficult to know how many people with Alzheimer’s in Switzerland are noncarriers or carry one copy of the gene.

There is another key difference regarding the treatment duration. According to Eisai, Swissmedic suggested Leqembi, which is given as biweekly infusions, should have a limited duration of 18 months. However, the drug was studied as a continuous therapy without a defined time period.

A Swissmedic spokesperson wrote in an email that it can’t comment on the “substance of the withdrawal of the application”, and no public assessment report was available before publication.

Global debate

Swissmedic isn’t the only regulator to wrestle with the decision to authorise the latest Alzheimer’s drugs. The US, China and Japan approved both treatments without any restrictions on the patient population based on APOE4 variants.

In Europe, a key committee in the European Medicines Agency (EMA) recommended rejecting Leqembi citing modest benefits and potential side effects, but changed directionExternal link after Eisai appealed. The committee found that for certain patients the benefits are greater than the risks. The European Commission authorised Leqembi on April 15, 2025 for patients with one or no copy of the APOE4 gene variant to mitigate the risks of ARIA.

The EMA committee also reversed its opinion on Kisunla eventually granting market authorisation in September 2025 with similar restrictions.

Even after approval, national health authorities have questioned whether the drugs offer sufficient benefits to be covered by health insurance. On February 19, the Gemeinsame Bundesausschuss (G-BA), Germany’s highest healthcare decision-making body, determinedExternal link Leqembi showed no evidence of added benefit compared with the current standard of care.

In mid-February, the Netherlands National Health Care Institute came to a similar opinion. The German health authorities are expected to release their positionExternal link on Kisunla in mid-April 2026.

The UK regulator approved Leqembi and Kisunla under similar conditions as the European bloc, but the country’s cost watchdog decided that the limited benefits of both drugs don’t justify their prices. This meant the drugs aren’t available to the wider public through the National Health Service (NHS) but only through private channels. The price is confidential in the UK. In the US Leqembi has a list price of $26,500 a year, and Kisunla of $32,000.

The Australian regulator rejected Leqembi two times. It argued the benefits outweighed risks for people who don’t carry any copies of the APOE4 gene but that safety had “not been satisfactorilyExternal link” established for patients who carry one copy. Eisai appealed the decision and after further review, the regulator approved Leqembi in September 2025 for patients with no or one APOE4 gene variant.

Neither Leqembi nor Kisunla is listed on the Australian Pharmaceutical Benefits Scheme (PBS)External link so patients must pay for it privately.

Opening the door

Neuroscientist Draganski didn’t comment on Eisai’s decision but said that “it is important to roll out these treatments in a controlled way and monitor patients carefully because they come with risks”.

Despite concerns, these treatments have changed the mindset about the disease. “Many people believed that forgetfulness is just a normal part of ageing but now we know we know we can define the cause and treat it,” said Draganski. “Leqembi and Kisunla are opening the door to better diagnostics and potentially more effective treatments. But they are not silver bullets.”

He added that it’s important new treatments are available in Switzerland for the country to remain a part of research discussions and build the data systems and infrastructure to provide the best care to patients.

Much about Alzheimer’s disease remains poorly understood. While amyloid plaques are a hallmark of Alzheimer’s, many trials targeting them have failed or not led to major improvements for patients.

Scientists are also trying to figure out why so many people with Alzheimer’s have two copies of the APOE4 variant yet 40% to 70% of people will never develop dementia. This has sparked heated debate over how Alzheimer’s disease should be defined – whether it should be based on biological markers like amyloid in the brain versus clinical symptoms.

After decades of setbacks, Alzheimer’s research is booming. According to one studyExternal link, there are 138 new drugs being tested for the disease in 182 trials.

Before Kisunla can be widely used in Switzerland, Eli Lilly and federal health authorities still need to agree on the price. As for Leqembi, which is manufactured in Switzerland by the company Biogen, Eisai told Swissinfo that it will continue to “analyse the situation and remains open to further dialogue with Swissmedic to understand what may be required for a potential future pathway”.

Edited by Virginie Mangin/sb