TOKYO, July 17, 2026 - (JCN Newswire) - Eisai Co., Ltd. announced today that the European Medicines Agency (EMA) has accepted for evaluation a marketing authorization application (MAA) for its in-house-discovered and developed orexin receptor antagonist lemborexant (generic name) for the treatment of adult patients with chronic insomnia.

Lemborexant is a dual orexin receptor antagonist (DORA) that inhibits orexin neurotransmission regulating sleep and wake states by binding competitively to the two subtypes of orexin receptors (OX1R and OX2R).1 Lemborexant acts on the orexin neurotransmitter system, which regulates wakefulness. Lemborexant is believed to facilitate sleep onset and decrease wakefulness during the night by blocking the orexin receptors.2

Chronic insomnia is characterized by difficulty falling asleep, staying asleep, or both despite an adequate opportunity to sleep for at least three months, and which can lead to fatigue, difficulty concentrating and irritability.3 In Europe, chronic insomnia is reported to affect approximately 4.7–22.1% of adults and is recognized as an important health concern with a considerable impact on patients’ quality of life and daily activities.4 In the current treatment of insomnia in Europe, medications that relatively broadly suppress (sedate) central nervous system activity are widely used. There is an increasing demand for treatment options that take into account their impact on daytime functioning.5 If approved, lemborexant will represent a new treatment option for insomnia patients in Europe.

Eisai considers neurology, including sleep disorders, as a therapeutic area of focus. Eisai strives to create innovative products in therapeutic areas with high unmet medical needs as soon as possible. The Company will further contribute to addressing the diverse needs of and increasing the benefits provided to those living with neurological diseases and their families.

Media Inquiries:

Public Relations Department,
Eisai Co., Ltd.
+81-(0)3-3817-5120

About lemborexant

Lemborexant, an orexin receptor antagonist, is Eisai’s in-house discovered and developed small molecule that inhibits orexin neurotransmission by binding competitively to the two subtypes of orexin receptors (orexin receptor 1 and 2).1 Fast on/off receptor kinetics of lemborexant to orexin receptors may influence lemborexant’s potential to facilitate improvements in sleep onset and maintenance with minimal morning residual effects.6 It has been approved for the treatment of insomnia in over 25 countries including Japan, the United States, Canada, Australia, and China, among others. 

TOKYO and CAMBRIDGE, Mass., July 15, 2026 - (JCN Newswire) - Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB) announced today that results from the real-world Lecanemab in Early Alzheimer's Disease (LEADER) Study show that nearly 83% of early Alzheimer’s disease (AD) patients enrolled in the study remained stable (75.9%) or improved (6.6%) while receiving LEQEMBI® therapy over an average of 17 months. The results were consistent across sex, race, ethnicity and APOE genotype. The data was presented during the “Developing Topics Session #3-33-DEV-A: Lecanemab Three Years Post-Approval: A Comprehensive Multicenter, Real-World, Retrospective Study (LEADER) in Diverse US Clinical Settings” at the Alzheimer’s Association International Conference® (AAIC®) 2026 in London and online.

AD is a chronic, progressive disease that requires ongoing treatment. LEQEMBI targets the underlying pathology of the disease and works in two ways throughout treatment - by removing insoluble (plaque) and soluble amyloid beta (protofibrils), helping to slow cognitive decline and loss of daily functioning. Data show continued treatment with LEQEMBI may be able to help keep patients in early AD for longer. Early AD includes mild cognitive impairment (MCI) due to AD and mild AD dementia.

LEADER Study Design

The three-year LEADER Study is a multicenter, retrospective real-world study designed to examine LEQEMBI utilization, treatment persistence, transition to maintenance therapy, safety, cognitive and functional assessments, and healthcare professional (HCP) implementation learnings in diverse U.S. clinical settings for patients with early Alzheimer's disease (AD). The study integrated deidentified chart and electronic medical record (EMR) data from 13 U.S. sites, HCP surveys and HCP interviews. This interim analysis included 432 patients with early AD who received at least seven LEQEMBI infusions as of May 2026.

Patient Characteristics at Baseline
* Mean age: 74 years
* Female Patients: 55.8%

Disease Stage at Baseline
* Mild cognitive impairment (MCI) due to AD: 63.9%
* Mild AD dementia: 36.1%.

Treatment
* The mean duration of LEQEMBI treatment was 520 days.• The mean number of LEQEMBI doses was 26.
* Change in disease stage was defined as:
- Stable - Patient remaining in the same disease stage (MCI due to AD or mild AD dementia)from baseline throughout the course of LEQEMBI treatment.
- Improvement - Patient transitioning from mild AD dementia at baseline to MCI due to AD overthe course of LEQEMBI treatment.
- Progression - Patient advancing from MCI at baseline to mild/moderate AD dementia or from mild AD dementia at baseline to moderate AD dementia throughout the course of LEQEMBI treatment. 

LEADER Study Key Findings

Real-World Evidence Shows Long-Term Benefit with Continuous LEQEMBI Treatment Across Sex,Race, Ethnicity and APOE Genotype

Overall Study Population Findings
* Of the 432 participants enrolled in the LEADER study, disease stage could be evaluated in 427. Among these patients with early Alzheimer's disease, 82.5% remained stable or improved while receiving LEQEMBI, with consistent results across sex, race, ethnicity, and APOE genotypegroups.
* 75.9% remained stable compared with baseline, meaning they remained in the same disease stagethroughout treatment.
* 6.6% improved from baseline, moving from mild AD dementia to MCI due to AD.
* Nearly 87% of patients chose to remain on LEQEMBI treatment.
* In analyses by APOE ε4 status, clinician-evaluated stable or improved disease stage was observed in:
  - 81.7% of APOE ε4 heterozygotes (stable: 73.8.%; improved: 7.9%)
  - 81.0% of APOE ε4 homozygotes (stable: 75.9%; improved: 5.2%). 

Maintenance Dosing Population Findings
• Of the 432 participants in the LEADER study, 155 transitioned to once-every-four-weeks intravenous(IV) maintenance treatment, and 14 transitioned to once-weekly subcutaneous (SC) maintenance treatment.
• Among the 155 participants who transitioned to IV maintenance therapy, nearly 81% remained stable(72.3%) or improved (8.4%).
• Of the 14 patients who transitioned to SC maintenance treatment, 12 (85.7%) maintained their disease stage.

Real-World Safety Consistent with U.S. FDA-Approved Label

Overall safety observations in this real-world study were consistent with the U.S. FDA-approved label.
• ARIA (amyloid-related imaging abnormalities)* was observed in 12.3% of patients overall; ARIA-E was observed in 6.3% and ARIA-H in 7.9% and isolated ARIA-H in 6.0%. Most ARIA cases were asymptomatic and mild in radiographic severity.
• No new ARIA-E events, macrohemorrhages or intracerebral hemorrhages greater than 1 cm were reported during once-every-four-weeks IV maintenance therapy.

APOE ε4 status safety observations were consistent with the overall cohort and the U.S. FDA-approved label.
• ARIA-E was observed in 5.3% of APOE ε4 noncarriers, 6.1% of APOE ε4 heterozygotes and 10.3%of APOE ε4 homozygotes.
• ARIA-H was observed in 12.1%, 4.8% and 12.1%, respectively.
• In APOE ε4 homozygotes, no severe ARIA was reported, and all graded ARIA cases were mild to moderate in radiographic severity. 

Antithrombotic therapy, including anticoagulants or antiplatelet medications, was used by 106 patients, representing 24.5% of the study population.
• Of these, 11 patients were receiving an anticoagulant, either alone or with an antiplatelet medication, and 95 patients were receiving antiplatelet therapy only.
• Among patients receiving antithrombotic therapy, the incidence of ARIA was not meaningfully different from that observed in patients not receiving antithrombotic therapy. 

* ARIA refers to amyloid-related imaging abnormalities that can be observed with anti-amyloid beta antibody treatment and includes ARIA-E, which involves edema/effusion, and ARIA-H, which involves hemosiderin deposition, including cerebral microhemorrhage, cerebral macrohemorrhage and superficial siderosis, as observed on brain magnetic resonance imaging (MRI).

Eisai serves as the lead for lecanemab’s development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

MEDIA CONTACTS
Eisai Co., Ltd.
Public Relations Department
TEL: +81 (0)3-3817-5120

Eisai Europe, Ltd.
EMEA Communications Department
+44 (0)7760 619251
Emea-comms@eisai.net

Eisai Inc. (U.S.)
Julie Edelman
+1-862-213-5915
Julie_Edelman@eisai.com

Biogen Inc.
Madeleine Shin
+1-781-464-3260
public.affairs@biogen.com

INVESTOR CONTACTS

Eisai Co., Ltd.
Investor Relations Department
TEL: +81 (0) 3-3817-5122

Biogen Inc.
Tim Power
+ 1-781-464-2442
IR@biogen.com 

For more information: https://www.eisai.com/news/2026/pdf/enews202641pdf.pdf 

TOKYO and CAMBRIDGE, Mass., July 15, 2026 - (JCN Newswire) - Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB), announced that the U.S. Food and Drug Administration (FDA) has approved a supplemental Biologics License Application(sBLA) for a once-weekly lecanemab-irmb subcutaneous injection (U.S. brand name: LEQEMBI IQLIK®) as an initiation dose for the treatment of early Alzheimer’s disease.

LEQEMBI IQLIK is administered via an autoinjector, introducing a convenient alternative to intravenous (IV) dosing from the start of treatment. For initiation, the approved regimen is 500 mg given once weekly as two 250mg injections, each delivered in approximately 15 seconds. LEQEMBI IQLIK may also be used for maintenance dosing at 360 mg once weekly after 18 months of IV or subcutaneous treatment. Throughout the entire treatment course - from initiation through maintenance - patients may receive LEQEMBI either as IV infusion oras subcutaneous (SC) injection with LEQEMBI IQLIK. Patients may also switch from IV to SC administration, or vice versa, providing greater convenience and flexibility in LEQEMBI administration.

LEQEMBI is indicated in the United States for adults with mild cognitive impairment (MCI) or mild dementia due to Alzheimer’s disease, collectively referred to as early Alzheimer’s disease. MCI due to AD is the earliest symptomatic stage of Alzheimer’s disease and can appear with subtle symptoms such as forgetfulness, confusion, or feeling at a loss for words.

Clinical Data Supporting FDA Approval of Subcutaneous Initiation Dosing The FDA approval of LEQEMBI IQLIK as an initiation dose is supported by a comprehensive clinical data package evaluating SC administration of lecanemab across multiple studies and a range of dosing regimens. Sub-studies within the Phase 3 Clarity AD long-term extension (LTE), following the 18-month core study in individuals with early Alzheimer’s disease, showed:

* Once-weekly subcutaneous administration achieved exposure equivalent to intravenous dosing, supporting similar clinical (efficacy) and biomarker (amyloid removal) benefits.

* The rate of exposure-related adverse events such as ARIA-E with SC administration is expected to becomparable with IV administration. There was no increase in isolated ARIA-H (i.e., ARIA-H in patients who did not also experience ARIA-E) for LEQEMBI compared to placebo.

* The overall safety profile of SC administration was generally similar to intravenous administration. Injection-related reactions were observed with subcutaneous LEQEMBI, most of which were localized, while systemic reactions were less frequently observed. 

“The approval of LEQEMBI IQLIK for initiation dosing marks a new era of Alzheimer's treatments," said Howard Fill it, MD, Co-Founder and Chief Science Officer Emeritus of the Alzheimer's Drug Discovery Foundation(ADDF). "For the first time, patients and their care partners have meaningful choice in how anti-amyloid treatment is delivered. As treatment approaches continue to expand, innovations in drug delivery will play acritical role in improving access to therapies, supporting the investigation of potential combination treatments, and advancing a precision medicine approach to Alzheimer’s care.”

Expanding Treatment Flexibility Across the Alzheimer’s Disease Care Pathway

The approval of LEQEMBI IQLIK as a subcutaneous initiation dose provides patients and care partners with the only at-home administration option throughout the Alzheimer’s disease treatment journey which could support access and delivery of care across healthcare settings. Subcutaneous administration may:

* Reduce the burden of clinic visits for patients and care partners

* Reduce reliance on infusion and associated healthcare resources

* Decrease treatment preparation and administration time, and nursing monitoring requirements

* Preserve infusion capacity for patients who prefer or require intravenous therapy

Insights from an autoinjector acceptability study indicated that 94% of patients with early Alzheimer’s disease and their care partners, found the LEQEMBI IQLIK device easy to use, with high levels of satisfaction and confidence in using it in an at-home setting.*

For more information: https://www.eisai.com/news/2026/pdf/enews202640pdf.pdf 

TOKYO, July 15, 2026 - (JCN Newswire) - Eisai Co., Ltd. today announced the latest findings on etalanetug (development code: E2814) showed that this investigational anti-MTBR antibody reduced levels of plasma eMTBRtau243, a key biomarker of Alzheimer’s disease (AD) tau tangle pathology. The investigational compound etalanetug may have the potential to bind to the microtubule-binding region (MTBR) of tau protein and prevent the seeding and propagation of tau pathology in the brain. Tau tangles are a hallmark of AD and are believed to be strongly associated with memory loss, cognitive decline, and disease progression.1 The findings were presented during the Featured Research Session, “Mechanisms Beyond Amyloid: Etalanetug Reduces Tau Tangle-Specific Plasma Biomarker eMTBR-tau243 in Dominantly Inherited Alzheimer’s Disease (DIAD),” at the Alzheimer’s Association International Conference® (AAIC®) 2026 in London and online.

The highly sensitive blood biomarker assay measuring eMTBR-tau243 was developed as a potential alternative for cerebrospinal fluid (CSF) and Positron Emission Tomography (PET) testing. This analysis evaluated changes in plasma tau biomarkers following etalanetug administration and compared them with changes observed in CSF biomarkers in individuals with DIAD enrolled in the Phase Ib/II Study 103(NCT04971733).

Key Findings

Plasma eMTBR-tau243 captures disease-specific pathological changes originating from taupathology in the brain

- Etalanetug reduced CSF eMTBR-tau243 by 62% at three months and by 89% at nine months.

- Etalanetug reduced plasma eMTBR-tau243 by 78% at 3 months and by more than 90% at 9 months,indicating that plasma eMTBR-tau243 closely mirrored disease-related changes captured in CSF.

- Plasma phosphorylated tau (p-tau217, p-tau181, and p-tau231) and t-tau increased after etalanetug administration in both individuals with DIAD and healthy adults. This change is considered to be attributable to non-CNS tau species derived from peripheral tissues being stabilized by binding to etalanetug in plasma, thereby inhibiting their degradation.

- Plasma eMTBR-tau243 was largely absent in healthy adults and detected only in patients with DIAD, suggesting it reflects disease-related tau pathology. Administration of etalanetug reduced levels of this biomarker.

- These results suggest that plasma eMTBR-tau243, unlike plasma phosphorylated tau species and ttau, is a biomarker that captures disease-specific pathological changes originating from tau pathologyin the brain.

Etalanetug acts on tau pathology in the brain, one of the underlying pathologies of AD

- Etalanetug reduced multiple CSF phosphorylated tau species and t-tau in patients with DIAD. Among these, p-tau205 is a marker reflecting late-stage tau pathology (T2 biomarker) in the Alzheimer's Association guidelines. 2

- These findings represent the first report of an anti-tau therapy reducing CSF p-tau205 in patients with DIAD.

These results highlight that etalanetug acts on tau pathology in the brain, one of the underlying pathologies of AD. Plasma eMTBR-tau243 may serve as a practical, less invasive biomarker that captures AD-specific pathological changes and may play an important role in the future clinical development of etalanetug.

* eMTBR-tau243 is a novel fluid biomarker consisting of tau fragments that include tau protein amino acid residue 243 and MTBR, with endogenous cleavage at the C-terminal side of residue 256. It is thought to arise during the formation of neurofibrillary tangles, a key pathological feature of AD, and a strong correlation has been shown between tau PET and eMTBR-tau243 in both plasma and CSF.3

** DIAD: Dominantly Inherited Alzheimer’s disease (DIAD) is a rare form of AD that causes memory loss and dementia in individuals — typically while they are in their 30s to 50s. The disease affects less than 1% of the total population of people with Alzheimer’s disease.

Media Inquiries:
Public Relations Department
Eisai Co., Ltd.
+81-(0)3-3817-5120

Eisai Europe, Ltd.
EMEA Communications Department
+44 (0) 797 487 9419
Emea-comms@eisai.net

Eisai Inc. (U.S.)
Libby Holman
+ 1-201-753-1945
Libby_Holman@eisai.com 

About etalanetug (E2814)

Etalanetug is an anti-MTBR (microtubule-binding region) tau antibody discovered through collaborative research between Eisai and University College London. It is designed to inhibit the propagation of tau seeds within the brain. Etalanetug is being developed as a potential disease-modifying therapy for tauopathies, including sporadic Alzheimer’s disease (AD).

Currently, etalanetug is being evaluated in two ongoing clinical studies: the Tau NexGen Phase II/III trial indominantly inherited Alzheimer’s disease (DIAD), conducted under the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU) and led by Washington University School of Medicine in St. Louis, added to the standard of-care anti-Aβ protofibril antibody lecanemab (brand name: LEQEMBI), and the Phase II Study 202, a global randomized trial in individuals with early sporadic AD, also assessing etalanetug added to lecanemab. In September 2025, etalanetug received Fast Track designation from the U.S. Food and Drug Administration (FDA).

Phase 1b/2 Study 103 (NCT04971733)

Phase 1b/2 Study 103 is an open-label study evaluating the safety, tolerability, and effects of etalanetug on tau-related biomarkers in cerebrospinal fluid (CSF) in participants with dominantly inherited Alzheimer's disease(DIAD).

TOKYO and CAMBRIDGE, Mass., July 13, 2026 - (JCN Newswire) - Eisai Co., Ltd. and Biogen Inc. (Nasdaq: BIIB)announced today that new data presented at the Alzheimer’s Association International Conference®(AAIC®) 2026 in London support that the LEQEMBI® (lecanemab) subcutaneous autoinjector (SC-AI)formulation offers efficacy and safety comparable to intravenous (IV) administration for people with early Alzheimer’s disease (AD). The data was featured during the “Lecanemab Subcutaneous Formulation in Early Alzheimer’s Disease: Emerging Clinical Evidence and Practical Use Considerations” Developing Topics Session #1-32-FRS-C.

AD is a chronic, progressive disease that requires ongoing treatment. LEQEMBI is an early AD treatment that targets the underlying pathology of the disease, helping to slow cognitive decline and loss of daily functioning. The lecanemab subcutaneous auto-injector (SC-AI) was developed to provide a more convenient alternative to intravenous (IV) dosing from the initiation of treatment.

Key Findings

This session presented data from the lecanemab SC-AI development program in early Alzheimer’s disease, including pharmacokinetic (PK), pharmacodynamic (PD), efficacy, safety and real-world patient and care partner experience findings. Results showed that once-weekly 500 mg SC-AI achieved drug exposure similar to the approved intravenous (IV) initiation regimen (10 mg/kg every two weeks), supporting the expectation of similar clinical efficacy and safety, independent of the route of administration. 

The subcutaneous dosing option may offer a convenient at-home alternative to IV infusion which could support access and delivery of care across healthcare settings.

Data Showed

• Bioequivalence Achieved: Once-weekly 500 mg SC-AI demonstrated bioequivalence to the IV initiation regimen (10 mg/kg every two weeks), with an exposure ratio of 104% (90% confidence interval [CI]: 99.1%–109%). Exposure remained consistent across body weight quartiles, demonstrating a stable pharmacokinetic profile in a broad patient population.
• Efficacy Driven by Exposure, Not Route of Administration: Amyloid removal measured by amyloid PET, clinical efficacy measured by CDR-SB, and the incidence of ARIA-E were driven by lecanemab exposure rather than route of administration. The 500 mg SC-AI initiation regimen achieved exposure comparable to the IV initiation regimen, supporting the expectation of acomparable efficacy and safety profile despite the different route of administration.
• Consistent Results Across Patient Populations: The 500 mg SC-AI initiation regimen demonstrated consistent exposure, amyloid clearance as measured by amyloid PET, clinical efficacy and safety across body weight groups. In addition, amyloid clearance and clinical outcomes were not meaningfully affected by body weight, supporting the appropriateness of a fixed-dose regimen.
• Flexible switching between IV and SC administration: Patients may also switch from IV to SC administration, or vice versa, and if a dose is missed patients can take it the next day or up to day six providing greater convenience and flexibility in LEQEMBI administration.

Safety Profile Aligned of SC LEQEMBI

• Overall safety profile of SC-AI was generally consistent with that observed for the IV formulation.
• Incidence of ARIA-E with the 500 mg SC-AI initiation regimen was predicted to be similar to that observed with the IV initiation regimen. 
• Injection-related reactions were observed with subcutaneous LEQEMBI, most of which were localized, while systemic reactions were less frequently observed.
• The incidence of anti-drug antibodies (ADA) was low, at 1.4% in the 500 mg SC-AI group. No neutralizing antibodies were observed, confirming that the low immunogenicity profile was maintained with the SC-AI formulation.

Clinical Trial Perspectives and Real-World Evidence: Sustained Clinical Benefit with SC-AI

• Data from two U.S. Alzheimer’s treatment centers (Alzheimer’s Research and Treatment Center,and First Choice Neurology and Visionary Investigators Network) provide early insight into clinical trial and real-world use of subcutaneous LEQEMBI:
  • At Alzheimer’s Research and Treatment Center, 28 patients receiving SC administration demonstrated slower cognitive decline as measured by CDR-SB over 36 months relative to a matched Alzheimer’s Disease Neuroimaging Initiative (ADNI) natural history cohort. The cohort included 25 patients newly initiated on SC administration and 3 patients who transitioned from IV administration.
  • In a separate case series from First Choice Neurology and Visionary Investigators Network, 10 of 11 evaluable patients (91%) showed improvement or remained stable on MMSE compared with baseline before maintenance therapy. At this center, patients who had received maintenance therapy with SC administration for at least 6 months were included in the analysis.
  • Patient and care partner surveys in these two sites demonstrated high satisfaction with subcutaneous LEQEMBI administration, with satisfaction rates ranging from 75% to 97%, convenience ratings from 83% to 97%, and willingness to recommend treatment ranging from 92% to 100%.

Results presented in this session further reinforce the importance of early and continuous treatment, highlighting how LEQEMBI SC initiation and maintenance administration provides greater optionality for long-term disease management. 

Eisai serves as the lead for lecanemab’s development and regulatory submissions globally with Eisaiand Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

MEDIA CONTACTS

Eisai Co., Ltd.
Public Relations Department
TEL: +81 (0)3-3817-5120

Eisai Europe, Ltd.
EMEA Communications Department
+44 (0) 797 487 9419
Emea-comms@eisai.net

Eisai Inc. (U.S.)
Libby Holman
+1201-753-1945
Libby_Holman@eisai.com

Biogen Inc.
Madeleine Shin
+1-781-464-3260
public.affairs@biogen.com

INVESTOR CONTACTS

Eisai Co., Ltd.
Investor Relations Department
TEL: +81 (0) 3-3817-5122

Biogen Inc.
Tim Power
+1-781-464-2442
IR@biogen.com

For more information: https://www.eisai.com/news/2026/pdf/enews202638pdf.pdf 

TOKYO, July 2, 2026 - (JCN Newswire) - Eisai Co., Ltd. announced today the company will present the latest findings from its Alzheimer’s disease (AD) research, including lecanemab (brand name: LEQEMBI®), our anti-amyloid beta (Aβ) protofibril antibody for the treatment of Alzheimer’s disease (AD) and anti-MTBR (microtubule binding region) tau antibody, etalanetug (E2814), at the Alzheimer’s Association International Conference® 2026 (AAIC®) from July 12-15 in London and online. Eisai will present 52 abstracts across its AD portfolio at AAIC. Highlights include a Developing Topics Session and a Featured Research Session on lecanemab, featuring four and six oral presentations, respectively, alongside 10 additional key oral presentations and 32 posters. Eisai will also host a symposium on early intervention in AD.​

Key Presentations

A Developing Topics Session will feature emerging clinical evidence and practical use considerations for the subcutaneous formulation of lecanemab, including clinical trial and real-world patient experience. A Featured Research Session will highlight data from the LEADER study evaluating real-world lecanemab use in diverse US clinical settings three years post-approval, including results on maintenance dosing with IV treatment every four weeks and the first reported findings of at-home subcutaneous administration.

Presentations on the Phase 3 AHEAD 3-45 study in preclinical AD will highlight progress of the trial including updates on participant retention and engagement.

Additional oral presentations will highlight a Phase 2 trial of etalanetug with background lecanemab, and the effect on tau pathology.

“We are sharing a broad and robust data set at AAIC spanning the Alzheimer’s disease continuum, multiple therapeutic targets, and modes of administration, underscoring our commitment to advancing care for this complex disease,” said Lynn D. Kramer, M.D., FAAN, Chief Clinical Officer, Deep Human Biology Learning (DHBL), Eisai. “Growing real-world experience with lecanemab, along with insights from patients, care partners, and clinicians, continues to add to our understanding of the value of early intervention, long-term treatment, and patient choice in care delivery.”

AAIC 2026 Presentations Relating to Eisai's Key Compounds and Research

Developing Topics Session #1-32-FRS-C: Lecanemab Subcutaneous Formulation in Early Alzheimer's Disease: Emerging Clinical Evidence and Practical Use Considerations
4:15-5:45 PM BST, Sunday, July 12

Featured Research Session #4-33-FRS-A: Lecanemab Three Years Post-Approval: A Comprehensive Multicenter, Real-World, Retrospective Study (LEADER) in Diverse US Clinical Settings
4:15-5:45 PM BST, Tuesday, July 14

Additional Oral Presentations 

Poster Presentations

**Poster viewing time is set from 7:30 AM – 4:15 PM BST on the date of presentation

Eisai-Sponsored Symposium
***Symposium is intended for HCPs only

Eisai serves as the lead of lecanemab development and regulatory submissions globally with both Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

This release discusses investigational uses of agents in development and is not intended to convey conclusions about efficacy or safety. There is no guarantee that such investigational agents will successfully complete clinical development or gain health authority approval.

MEDIA CONTACTS

Public Relations Department
Eisai Co., Ltd.
TEL: +81 (0)3-3817-5120

Eisai Europe, Ltd.
(Europe, Australia, New Zealand and Russia)
EMEA Communications Department
+44 (0) 7739-600-678
EMEA-comms@eisai.net

Eisai Inc. (U.S.)
Julie Edelman
+1-862-213-5915
Julie Edelman@eisai.com

About lecanemab (generic name, brand name: LEQEMBI®)

Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aβ).

Lecanemab has been approved in 53 countries and regions including Japan, the United States, China, Europe, South Korea, Taiwan, and Saudi Arabia, and is under regulatory review in 6 countries. Following the initial phase with treatment every two weeks for 18 months, intravenous (IV) maintenance dosing with treatment every four weeks was approved in 8 countries including the U.S., China, the UK, and others, and applications have been filed in 12 countries and regions. The U.S. FDA approved Eisai’s Biologics License Application (BLA) for subcutaneous maintenance dosing with LEQEMBI IQLIK in August 2025. A Supplemental Biologics License Application (sBLA) for initiation treatment was accepted in January 2026 and granted Priority Review. The sBLA has been assigned an extended Prescription Drug User Fee Act (PDUFA) action date of August 24, 2026. In November 2025, an application for a subcutaneous injectable formulation in Japan was submitted. In January 2026, the Biologics License Application (BLA) for the subcutaneous formulation was accepted in China. In December 2025, Lecanemab (IV) has been included in the “Commercial Insurance Innovative Drug List”, recently introduced by the National Healthcare Security Administration (NHSA) of China.

Since July 2020 the Phase 3 clinical study (AHEAD 3-45) for individuals with preclinical AD, meaning they are clinically normal and have intermediate or elevated levels of amyloid in their brains, is ongoing. AHEAD 3-45 is conducted as a public-private partnership between the Alzheimer's Clinical Trial Consortium that provides the infrastructure for academic clinical trials in AD and related dementias in the U.S, funded by the National Institute on Aging, part of the National Institutes of Health, Eisai and Biogen. Since January 2022, the Tau NexGen clinical study for Dominantly Inherited AD (DIAD), that is conducted by Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), led by Washington University School of Medicine in St. Louis, is ongoing and includes lecanemab as the backbone anti-amyloid therapy.

About Protofibrils

Protofibrils are believed to contribute to the brain injury that occurs with AD and are considered to be the most toxic form of soluble Aβ, having a primary role in the cognitive decline associated with this progressive, debilitating condition.1 Protofibrils cause injury to neurons in the brain, which in turn, can negatively impact cognitive function via multiple mechanisms, not only increasing the development of insoluble Aβ plaques but also increasing direct damage to brain cell membranes and the connections that transmit signals between nerve cells or nerve cells and other cells. It is believed the reduction of protofibrils may prevent the progression of AD by reducing damage to neurons in the brain and cognitive dysfunction.2

About etalanetug (E2814)

Etalanetug is an anti-MTBR (microtubule-binding region) tau antibody discovered through collaborative research between Eisai and University College London. It is designed to inhibit the propagation of tau seeds within the brain. Etalanetug is being developed as a potential disease-modifying therapy for tauopathies, including sporadic Alzheimer's disease (AD).

Currently, etalanetug is being evaluated in two ongoing clinical studies: the Tau NexGen Phase 2/3 trial in dominantly inherited Alzheimer's disease (DIAD), conducted under the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU) and led by Washington University School of Medicine in St. Louis, added to the standard-of-care anti-Aβ protofibril antibody lecanemab (brand name: LEQEMBI), and the Phase 2 Study 202, a global randomized trial in individuals with early sporadic AD, also assessing etalanetug added to lecanemab. In September 2025, etalanetug received Fast Track designation from the U.S. Food and Drug Administration (FDA).

About the Collaboration between Eisai and Biogen for AD

Eisai and Biogen have been collaborating on the joint development and commercialization of AD treatments since 2014. Eisai serves as the lead of LEQEMBI development and regulatory submissions globally with both companies co-commercializing and co-promoting the product and Eisai having final decision-making authority.

About the Collaboration between Eisai and BioArctic for AD

Since 2005, Eisai and BioArctic have had a long-term collaboration regarding the development and commercialization of AD treatments. Eisai obtained the global rights to study, develop, manufacture and market lecanemab for the treatment of AD pursuant to an agreement with BioArctic in December 2007. The development and commercialization agreement on the antibody lecanemab back-up was signed in May 2015. 

TOKYO, July 2, 2026 - (JCN Newswire) - University College London (UCL) and Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito) have signed a new agreement to extend their long-standing collaboration in drug discovery and development for five more years, taking the partnership through to 2030. This alliance reinforces a unique model built on trust, combining academic excellence with industry expertise to accelerate innovation in neuroscience drug discovery, investigating new ways of treating neurodegenerative diseases such as Alzheimer’s, Parkinson’s, Amyotrophic Lateral Sclerosis and other related disorders.

Eisai, a Tokyo-headquartered pharmaceutical company, is globally recognised for pioneering treatments for dementia and other neurodegenerative conditions. One of the most notable outcomes of the UCL–Eisai collaboration to date is the anti-MTBR tau antibody E2814, which was first discovered as part of collaborative research between the two organisations.  The antibody is currently being evaluated in the DIAN-TU Phase II/III Clinical trial for Dominantly Inherited Alzheimer’s Disease (DIAD), as well as the Phase II clinical trial for sporadic early AD (Study 202).

In total, eight drug discovery projects focusing on a variety of therapeutic targets have been supported through a £10 million investment to date, with further investment committed over the next five years as part of the extension. These efforts are underpinned by a strong commitment to knowledge exchange, reflected in more than 30 scientific outputs including publications and presentations to date, ensuring jointly acquired insights are shared with the wider community, and helping to move the field closer to delivering meaningful outcomes for patients.

The renewed agreement launches with collaborative projects targeting novel therapeutic pathways while opening the door to UCL researchers across disciplines to bring forward innovative ideas for co-development.

Over the next five years, the alliance will focus on:

• Moving promising collaborative projects through recognised stage gates of the drug development pathway
• Actively seeking and advancing high-potential drug discovery projects to tackle neurodegeneration
• Strengthening the neurodegeneration research talent pipeline by creating specialist scientist roles across joint projects
• Enabling researchers to publish and present findings to the wider scientific community, including at international conferences
• Sustaining close engagement at every level, from senior leadership to project scientists, across both organisations.

First launched in 2012 and spearheaded by the UCL Translational Research Office (TRO) and the Faculty of Brain Sciences, the Eisai–UCL alliance exemplifies a bespoke partnership model that goes beyond traditional academia-industry collaborations. Over the past decade, it has created a dynamic ecosystem that accelerates translational research towards the clinic, nurtures early-stage projects, connects scientific pain points with the right expertise and invests in talent development through initiatives such as jointly funded PhDs and long‑term knowledge sharing between the organisations.

Professor Geraint Rees, UCL’s Vice-Provost (Research, Innovation & Global Engagement), said: “Long‑term academic–industry partnerships of this depth are rare. The UCL–Eisai alliance shows what can be achieved addressing global health challenges when there is sustained alignment and trust. This five‑year extension gives us the stability to deepen the science, accelerate translation from lab to market, and develop the next generation of research leaders.”

Professor Tom Warner, Professor of Clinical Neurology, UCL Queen Square Institute of Neurology, co-chair of the UCL-Eisai Joint Steering Committee, said: “This renewal reflects the maturity of the collaboration and our shared ambition to take on challenging scientific questions in neurodegenerative disease. The next phase enables us to progress promising research discoveries into therapies with a clear pathway towards patients.”

Dr Katsutoshi Ido, Eisai’s Chief Scientific Officer and co-chair of the Joint Steering Committee, said: “What distinguishes the collaboration with UCL is the depth of neuroscience expertise and the ability to connect early discovery with patient benefit. The Translational Research Office plays an essential role in supporting the partnership, and by working closely together we can more effectively advance promising research towards new treatments for patients.”

Eisai has also announced this month a strategic investment at its manufacturing site in Hatfield, Hertfordshire, United Kingdom, supported by the UK Government under the Life Sciences Innovative Manufacturing Fund (LSIMF), subject to terms and conditions. It demonstrates Eisai’s long-term commitment to strengthening its relationship with the United Kingdom.

MEDIA CONTACTS

Eisai Co., Ltd.
Public Relations Department
TEL：+81 (0)3-3817-5120

University College London
Kristy Tsang
kristy.tsang@ucl.ac.uk

About University College London (UCL)

UCL is a global top 10 university, set up in London 200 years ago to offer education for all. Today, we gather 60,000 staff and students, from over 150 countries, to create a unique city within a city – a research and innovation powerhouse that leads the world in subjects spanning the arts, sciences, technology and the humanities. We’ve nurtured 33 Nobel Prize winners, because here, brave ideas have the scale and the support they need to succeed. We are University College London. And here, it can happen. UCL turns 200 in 2026. Join us for a year of bicentennial events and celebration. www.ucl.ac.uk 

About Eisai Co., Ltd.

Eisai's Corporate Concept is "to give first thought to patients and people in the daily living domain, and to increase the benefits that health care provides." Under this Concept (also known as human health care (hhc) Concept), we aim to effectively achieve social good in the form of relieving anxiety over health and reducing health disparities. With a global network of R&D facilities, manufacturing sites and marketing subsidiaries, we strive to create and deliver innovative products to target diseases with high unmet medical needs, with a particular focus in our strategic areas of Neurology and Oncology. In addition, we demonstrate our commitment to the elimination of neglected tropical diseases (NTDs), which is a target (3.3) of the United Nations Sustainable Development Goals (SDGs), by working on various activities together with global partners. For more information about Eisai, please visit www.eisai.com (for global headquarters: Eisai Co., Ltd.), and connect with us on X, LinkedIn and Facebook. The website and social media channels are intended for audiences outside of the UK and Europe. For audiences based in the UK and Europe, please visit http://www.eisai.eu/ and Eisai EMEA LinkedIn. Eisai actively promotes open innovation with external partners, including academia, biotechnology companies, startups, and pharmaceutical companies worldwide. For partnership opportunities, technology proposals, or research collaborations, please visit: Global Open Innovation and for EMEA External Innovation, contact: externalinnovation@eisai.net 

TOKYO, May 21, 2026 - (JCN Newswire) - Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) announced today the presentation of clinical research across its oncology portfolio and pipeline during the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (#ASCO26), which is taking place in Chicago, Illinois and online from May 29 to June 2.

Notable data include findings from a real-world evidence analysis comparing first-line lenvatinib (LENVIMA®), the orally available multiple receptor tyrosine kinase inhibitor (TKI) discovered by Eisai, versus dabrafenib (BRAF inhibitor) plus trametinib (MEK inhibitor) in patients with BRAF-mutated differentiated thyroid cancer (DTC). The poster presentation will share insights from real-world clinical practice to inform treatment considerations for patients with this molecularly defined subset of DTC (Abstract #6052). Currently, lenvatinib is recommended as a preferred Category 1 systemic therapy regimen for the treatment of progressive, radioactive iodine-refractory DTC in the National Comprehensive Cancer Network® (NCCN®)*1 Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Thyroid Carcinoma.

An additional poster presentation will feature an analysis from the pivotal Phase 3 CLEAR study evaluating efficacy outcomes by patterns of progression in patients with advanced renal cell carcinoma (RCC) who received lenvatinib plus pembrolizumab (KEYTRUDA®*2) MSD’s (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy, versus sunitinib (multiple receptor TKI) in the first-line setting. These findings build on the body of evidence supporting the established role of lenvatinib plus pembrolizumab in the first-line treatment setting for patients with advanced RCC (NCT02811861; Abstract #4527). Lenvatinib incombination with pembrolizumab is recommended as a preferred Category 1 first-line systemic therapy regimen for the treatment of patients with advanced clear cell RCC and a preferred Category 2A systemic therapy regimen for the treatment of patients with advanced non-clear cell RCC in the NCCN Guidelines® for Kidney Cancer.

"Lenvatinib continues to play an important role in the treatment of some of the most difficult-to-treat cancers, supported by more than a decade of clinical and real-world evidence," said Dr. Corina Dutcus, Senior Vice President, Oncology Global Clinical Development Lead at Eisai Inc. "At ASCO 2026, Eisai is presenting new research that reinforces this foundation and deepens the clinical evidence for lenvatinib across its established indications, giving healthcare providers valuable information to help them care for their patients. This work, alongside our ongoing pipeline research, reflects Eisai's dedication to providing support for the communities we serve as part of our human health care concept."

Additional research from Eisai’s pipeline includes an online publication highlighting analyses from Phase1 trials evaluating E7386*3, a CREB-binding protein (CBP)/β-catenin interaction inhibitor, to inform cardiac safety assessments in early-stage oncology development (Abstract #e24005).

This release discusses investigational compounds and investigational uses for FDA-approved products. It is not intended to convey conclusions about efficacy and safety. There is no guarantee that any investigational compounds or investigational uses of FDA-approved products will successfully complete clinical development or gain FDA approval.

The full list of Eisai presentations is included below. These abstracts will be made available via the ASCO website on Thursday, May 21, 2026, at 5:00 PM EDT

The following presentations represent studies including lenvatinib treatment sponsored by MSD.

In March 2018, Eisai and MSD, through an affiliate, entered into a strategic collaboration for the worldwide co-development and co-commercialization of lenvatinib, both as monotherapy and in combination with MSD’s anti-PD-1 therapy, pembrolizumab. KEYTRUDA plus LENVIMA is approved in the U.S., the EU, Japan and other countries for the treatment of advanced RCC and certain types of advanced endometrial carcinoma. Lenvatinib is approved as KISPLYX® for advanced RCC in the EU.

The following presentation includes a study on taletrectinib treatment sponsored by Nuvation Bio Inc.(Corporate Headquarters: New York, “Nuvation Bio”).

In January 2026, we acquired from Nuvation Bio the exclusive rights to develop, obtain regulatory approval for, and commercialize taletrectinib, next-generation ROS1 inhibitor for the treatment of ROS1-positivenon-small cell lung cancer (NSCLC) in Europe, the Middle East, North Africa, Russia, Turkey, Canada, Australia, New Zealand, Singapore, the Philippines, Indonesia, Thailand, Malaysia, Vietnam, and India. Following the submission of a marketing authorization application (MAA) to the European Medicines Agency (EMA) in March 2026, which was validated and accepted for full approval consideration with a standard review timeline, additional filings are planned for the U.K., Canada and other regions included in Eisai’s licensed territories.

The following presentation includes a study on serplulimab treatment sponsored by Shanghai Henlius Biotech, Inc. (Headquarters: Shanghai, “Henlius”).

In February 2026, we acquired from Henlius the exclusive rights to commercialize serplulimab, a novelanti-PD-1 monoclonal antibody in Japan. In Japan, Henlius is currently conducting a Phase II bridging clinical trial for extensive-stage small cell lung cancer (ES-SCLC), and plans to submit an application for fiscal year 2026 based on the results of this trial as well as the Phase III clinical trial data that supported approvals for this indication in China and Europe.

Media Inquiries:

Public Relations Department,
Eisai Co., Ltd.
+81-(0)3-3817-5120

1. Eisai’s Focus on Cancer

Eisai positions Oncology as one of its key strategic areas, and aims to contribute to the cure of cancers through the discovery of innovative new drugs with new targets and mechanisms of action under the Deep Human Biology Learning (DHBL) drug discovery and development organization. 

By utilizing biomarker data obtained from our products to elucidate the mechanisms of the incidence and root causes of cancer, as well as drug resistance, and using Eisai Group's precision chemistry technology to turn undruggable intracellular therapeutic targets into druggable ones, we will create new backbone therapeutic drugs.

*1 NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way.
*2 KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc., Rahway,NJ, USA.
*3 E7386 is created through collaboration research between Eisai and PRISM BioLab Co., Ltd. (Headquarters: Kanagawa).