# Eisai (company)

Eisai Co., Ltd. (Japanese: エーザイ株式会社, Hepburn: Ēzai Kabushiki-gaisha) is a Japanese pharmaceutical company headquartered in Tokyo, Japan. It has some 10,000 employees, among them about 1,500 in research. Eisai is listed on the Tokyo Stock Exchange and is a member of the Topix 100 and Nikkei 225 stock indices.

## History

Nihon Eisai Co. Ltd. was established in 1941. In 1944, merger with Sakuragaoka Research Laboratory resulted in creation of Eisai Co. Ltd. The American subsidiary of the company, Eisai Inc., was established in 1995.
On November 25, 1996, Eisai received approval from the United States Food and Drug Administration (USFDA) for Aricept (donepezil), a drug discovered in the company's labs and co-marketed with Pfizer.
Three years later in 1999, the company received USFDA approval for Aciphex (rabeprazole), a drug co-marketed with Johnson & Johnson.
In September 2006, the company acquired four oncology products from Ligand Pharmaceuticals.
In April 2007, Eisai acquired Exton, Pennsylvania-based Morphotek, a company developing therapeutic monoclonal antibodies for the treatment of cancer, rheumatoid arthritis, and infectious diseases.
In December 2007, Eisai acquired MGI Pharma, a company specializing in oncology, for US$3.9 billion. This event brought Dacogen (decitabine), Aloxi (palonosetron), Hexalen (altretamine) for ovarian cancer, and the Gliadel Wafer (carmustine) for brain tumors into the Eisai product portfolio.
In 2009, Eisai received the Corporate Award from the National Organization for Rare Disorders (NORD) for the development of Banzel (rufinamide).
In June 2023, the company suffered from a ransomware attack, causing a shutdown of some of its logistical systems.
Lecanemab, branded as "Leqembi" was approved by the U.S. Food and Drug Administration (FDA) in January 2023 under an Accelerated Approval pathway. The approval was converted into a traditional approval in July 2023.

## Locations

Eisai Co., Ltd. is based in Tokyo, Japan, while its American subsidiary, Eisai Inc., is headquartered in Nutley, New Jersey. Eisai Inc. is led by Ivan Cheung as CEO. Eisai maintains medical research headquarters in Nutley as well as at locations in Japan, the United Kingdom, the Research Triangle in North Carolina, and Massachusetts where the Eisai Research Institute and the Genetics Guided Dementia Discovery (G2D2) institute are based.
The company has manufacturing sites in Japan, North Carolina (USA), Maryland (USA), Bogor (Indonesia), Suzhou (China), Tainan (Taiwan), Visakhapatnam (India) and Hatfield, Hertfordshire (UK). Eisai has marketing operations in 19 European countries as well as the Asia-Pacific region.

## Products

Some of the key products that Eisai produces or markets with partners include:
* Aciphex/Pariet (rabeprazole) - Gastroesophageal reflux disease
* Actonel (risedronic acid) - Osteoporosis (Japan)
* Aloxi (palonosetron) - Chemotherapy-induced nausea and vomiting
* Aricept (donepezil) - Mild to moderate dementia for Alzheimer's Disease patients
* Banzel/Inovelon (rufinamide) - Seizures related to Lennox-Gastaut Syndrome
* Belviq (lorcaserin) - Obesity
* Dayvigo (lemborexant) - Insomnia
* Fragmin (dalteparin) - Deep vein thrombosis and pulmonary embolism
* Fycompa (perampanel) - Partial-onset seizures
* Gliadel Wafer (carmustine) - Treatment for Brain Tumors
* Halaven (eribulin) - Metastatic breast cancer
* Iomeron (iomeprol) - Non-ionic contrast medium
* Lenvima (lenvatinib) - Thyroid Cancer or Kidney Cancer
* Leqembi (lecanemab) - Alzheimer's disease
* Methylcobal (methylcobalamin) - Peripheral neuropathy
* Myonal (eperisone) - Muscle relaxant
* Selbex (teprenone) - Gastric ulcers and gastritis
* Zonegran (zonisamide) - Partial-onset seizures

### Aricept

Aricept accounted for 40% of Eisai's revenue as of March 2010. The main competitor to Aricept is a generic formulation from Ranbaxy Labs. Eisai has pursued development of alternative formulations in order to extend the marketable lifetime of the product.