As global pharmaceutical companies have successively achieved breakthroughs in the development of new drugs for Alzheimer's disease, research and development (R&D) in the field of dementia treatment has reached a significant turning point. Currently, the only two Alzheimer’s medications approved for market by the U.S. Food and Drug Administration (FDA) are Leqembi (ingredient name lecanemab), jointly developed by the Japanese pharmaceutical company Eisai and the U.S. company Biogen, and the U.S. pharmaceutical company Eli Lilly's Kysruva (donanemab).
Experts believe that the introduction of new Alzheimer’s drugs will accelerate growth in the dementia treatment market. Although it takes considerable time for the first new drug to emerge, once one drug is successful, it is characteristic of the pharmaceutical market for related drugs to be developed explosively.
According to a report from the Korea Institute of Science and Technology Information (KISTI) last October, the global market for Alzheimer's disease treatments is projected to grow from $1.737 billion (approximately 2.4 trillion won) in 2021 to $33.872 billion (46.6 trillion won) by 2027.
◇Expanding from intravenous to subcutaneous injections
According to the medical community on the 16th, the trailblazers developing new Alzheimer’s drugs are expanding the market by innovating the drug format. Both Eisai and Eli Lilly are advancing Alzheimer's treatments into subcutaneous injection formulations (SC).
Both Leqembi and Kysruva are antibody treatments administered via intravenous (IV) formulations designed to eliminate abnormally accumulated amyloid beta proteins that cause Alzheimer’s disease. Amyloid beta is originally a protein that protects nerve cells, but when it separates from nerve cells and aggregates, it instead damages them. It is known that amyloid beta proteins accumulate up to 15 years before dementia symptoms appear, leading to cognitive decline.
The subcutaneous injection formulation of Leqembi, being developed by Eisai, received Fast Track designation from the FDA this past May. The company aims to submit relevant materials by the end of this month and obtain final FDA approval by the end of 2026. Eli Lilly is developing the subcutaneous injection formulation Alzheimer’s treatment candidate ‘Lembetrenatug (LY3372993)’ as a follow-up to Kysruva. They are currently conducting Phase 3 clinical trials involving Alzheimer’s patients aged 60 to 85, with plans to complete the trials in March 2026.
The subcutaneous injection method has the advantage of requiring a shorter administration time than the existing intravenous formats and allows patients to self-administer the treatment at home without visiting a hospital. Pharmaceutical companies are pursuing strategies to increase market share by enhancing patient convenience.
Moon So-young, academic director of the Korean Dementia Society and a professor in the neurology department at Ajou University Hospital, noted, “If Alzheimer’s disease treatments are developed in subcutaneous forms, patients can self-administer the treatment like diabetic patients use insulin,” adding that “subcutaneous injections will enhance accessibility for Alzheimer’s treatment and improve patient convenience.”
◇Challenging to reduce side effects and enhance treatment efficacy
Currently, Alzheimer’s disease treatments have been reported to have side effects such as cerebral hemorrhage and cerebral edema. This is because the removal of amyloid beta proteins can cause swelling or bleeding in the brain. It’s akin to peeling a poster off a wall, causing the wallpaper to come off as well. The pharmaceutical industry and academia are challenging the task of reducing side effects while increasing treatment efficacy.
Roche, the Swiss pharmaceutical company, is a prime example. Roche is currently conducting Phase 1 and 2 clinical trials for its antibody treatment candidate, ‘tronsetanemab,’ which targets amyloid beta. After previously failing in Phase 3 trials for Alzheimer’s medication, Roche resumed development by applying a technology to penetrate the blood-brain barrier, aimed at improving the drug's ability to infiltrate the brain. While oxygen and nutrients pass from blood vessels to the brain, larger foreign substances such as proteins are blocked by the endothelial cells surrounding the blood vessels.
Research and development of therapies with different mechanisms than Leqembi and Kysruva are also ongoing. Kei Cho, a professor in the neuroscience department at King’s College London in the U.K., stated they are developing new Alzheimer’s treatments targeting tau proteins together with a British biotech company and a Japanese multinational corporation. Tau is also a protein that plays a structural role in maintaining nerve cells, but when it detaches from its original position and accumulates within cells, it causes cognitive issues.
In South Korea, new Alzheimer’s medications are also under development. Cureverse, a research corporation of the Korea Institute of Science and Technology (KIST), is developing an Alzheimer’s treatment candidate ‘CV-01’ in pill form. Currently in Phase 1 trials, it exported technology to the Italian pharmaceutical company Angelini Pharma valued at 500 billion won. CV-01 works by regulating brain inflammation. The company stated that it is designed to be significantly smaller than antibody treatments, allowing it to easily cross the blood-brain barrier.
Chaperone is developing an Alzheimer’s treatment candidate ‘NuCerin.’ NuCerin inhibits the excessive production of immune proteins called cytokines that cause inflammation, triggered by amyloid beta accumulated in the brain. This mechanism helps preserve cognitive abilities by preventing the death of nerve cells.
LNJ Bio is developing a new candidate ‘AL04’ that has a treatment mechanism for removing both amyloid beta and tau proteins. Huons is also developing the Alzheimer’s antibody treatment candidate HLB1-014. Collaborating with Seoul National University and Yonsei University, they are developing a technology to enhance the brain delivery of drugs using ultrasound.
Professor Moon So-young remarked, “With new Alzheimer’s drugs emerging one after another, research and development of dementia treatments worldwide is increasing explosively, and in the future, it may be possible for dementia to become a manageable disease like diabetes.”