The overall treatment system on-site has been changing with the introduction of Leqembi, a new dementia drug that was released 6 months ago in Korea.

In response, experts are evaluating the therapeutic effects and side effects of Leqembi (lecanemab, Eisai Korea) while demanding improvements to the health insurance reimbursement system in various areas, such as testing costs.

At the same time, they are expressing anticipation for other new dementia drugs from global pharmaceutical companies that are likely to be introduced in Korea. The introduction of just one new global drug has changed the atmosphere on-site and in academic activities.

#According to the medical community on the 12th, Eisai Korea’s Leqembi (Lecanemab), which was launched in Korea at the end of last year, has passed the Drug Committees (DCs) of major university hospitals and is rapidly expanding its prescriptions in Korea.

Leqembi is a new treatment that removes amyloid beta (Aβ), one of the main causative substances of Alzheimer's disease. It specifically binds to soluble amyloid beta protofibrils and insoluble amyloid beta fibrils—the most toxic forms of amyloid beta—to reduce amyloid beta plaques in the brain.

In particular, it is the first antibody therapy to receive full approval from the FDA in July 2023 for its efficacy and safety in delaying the progression of Alzheimer's disease and cognitive decline by removing the causative agent. In Korea, it was approved by the MFDS in May last year and has been prescribed in general hospitals since the end of November.

However, there are limitations in that it can only be used in medical institutions that meet certain standards, as it requires collaboration with radiologists, neurologists, or other specialists to assess amyloid-related imaging abnormalities (ARIA) such as cerebral vascular lesions and cerebral hemorrhage, as well as facilities capable of administering Leqembi intravenously every 2 weeks and personnel to monitor adverse drug reactions.

Nevertheless, Lecanemab is being rapidly adopted and utilized on-site not only at university hospitals but also at regional hub general hospitals, due to the disease's characteristic lack of a fundamental cure.

According to an internal evaluation by the Korean Dementia Association, approximately 700 cases have been treated using the medication 6 months after its introduction in Korea.

Seong Hye Choi, president of the Korean Dementia Association (Department of Neurology, Inha University Hospital), stated, “A patient weighing 50kg bears approximately KRW 1 million for a single administration of Leqembi. Considering that it is administered every 2 weeks, this amounts to KRW 2 million per month, and KRW 24 million per year for the patient. For a 40kg patient, the cost per administration is approximately KRW 800,000. Some patients are covered with indemnity insurance, and the treatment being well received onsite, even better than expectations.”

Additionally, in clinical settings, there is a projection that the incidence of adverse reactions related to brain edema, particularly ARIA, observed during MRI scans in the course of Leqembi’s introduction may be relatively lower than what was shown in clinical studies.

Kee Hyung Park, Chair of the Strategy and Planning Committee (Department of Neurology, Gachon University Gil Medical Center), said, “Japan introduced Leqembi before South Korea, and the drug is being actively used as it is covered by reimbursement. Among approximately 8,000 cases, ARIA occurred in 537 cases, which is 6.7% of all patients.” He added, “During the initial clinical trials, the incidence rate of ARIA was reported to be between 12% and 17%.”

Park added, “In Korea, there have been no cases of patients experiencing severe side effects after receiving Leqembi. While it is still too early to draw definitive conclusions, it is reasonable to expect that side effects may be less common in Asians compared to Westerners.

Amidst this, doctors have suggested that reimbursement for Leqembi itself is necessary, but that reimbursement for tests such as MRI is more urgent.

Currently, MRI tests are required to assess cerebral vascular lesions and ARIA in patients receiving Leqembi. The logic is that tests that bring less health insurance burden should be reimbursed first, followed by a discussion on reimbursement for the drug itself.

Choi said, “According to MFDS guidelines, patients receiving Leqembi must undergo MRI scans. This means that MRI scans must be performed before the fifth, seventh, and fourteenth injections. If reimbursement is applied to this part of the treatment, it will be able to somewhat reduce the burden on patients.”

Choi also pointed out that long-term support for the costs of injection rooms and dedicated nurses (coordinators) provided for severe cancer patients is also necessary for dementia.  

Recently, Ewha Womans University Mokdong Hospital and Ewha Womans University Seoul Hospital introduced dedicated nurses following the adoption of Leqembi, but many medical institutions find it difficult to operate such programs due to the burden of labor costs.

Jee Hyang Jeong of the Department of Neurology at Ewha Womans University Seoul Hospital (Chair, Public Relations Committee, KDA) explained, “When patients and their families request Leqembi treatment, it is necessary to provide detailed explanations about the treatment process, side effects, MRI scans, and other related matters. This entire process typically takes 30 to 40 minutes. We recognize this as a critically important process and have begun operating with dedicated staff internally. This was a big and dedicated decision on the hospital’s part.”

Jeong added, “Ultimately, dementia is similar to cancer. We need to hire dementia specialists to educate patients and their families. The same applies to infusion rooms. Comprehensive improvements are needed, including reimbursement for the use of infusion rooms and labor costs, similar to cancer treatment.”

Following the use of Leqembi on-site, expectations are also rising for another new dementia drug, Lilly's Kisunla (donanemab).

Lilly's Kisunla cleared the regulatory hurdle - FDA - last year. Kisunla demonstrated efficacy in delaying cognitive decline in patients with early-stage Alzheimer's disease in the Phase III TRAILBLAZER-ALZ2 study. In the clinical trial, it delayed cognitive decline regardless of the disease's progression or pathological stage.

Particularly, compared to Leqembi, it is evaluated as having a high potential for utilization in Korea due to improved convenience in patient administration.

Choi said, “Kisunla has the advantage of a relatively long administration cycle and the possibility of discontinuing treatment midway through the course. I understand that Lilly, the manufacturer of Kisunla, is in discussions with the MFDS for its introduction in Korea. With mixed results in global markets, I expect the MFDS to make a decision based on the domestic situation.”

Park also noted, “Rather than focusing on why approval was granted in the U.S. but not in Europe, we should examine the characteristics of the drug and its differences from existing medications. We need to assess this and consider how patients can individually select the appropriate medication for treatment when approval is granted domestically.”