Born in Itose Village, Nyu District, Fukui Prefecture
Toyoji departs his hometown at age 15 and moves to Osaka
Toyoji joins Winkel Trading Company, studying English, German, Chinese, and bookkeeping
Toyoji leaves Winkel Trading Company and enlists in the Imperial Guard Second Regiment at Kudan, Tokyo
After discharge, Toyoji joins Tamson Trading Company, dealing with imported medicines
Toyoji moves to Tokyo and joins Tanabe Motozaburo Shoten (now Tanabe Mitsubishi Pharma)
Toyoji embarks on a approximately 7-month inspection tour of Southeast Asia
Toyoji at Tanabe Motozaburo Shoten develops aromatic castor oil 'Castarol' and massage medicine 'Salomethil'
The Great Kanto Earthquake occurs, causing the main store of Tanabe Motozaburo Shoten to burn down, leading to a temporary hardship
Toyoji handles Japan's first blood pressure lowering drug 'Animaza' at Tanabe Motozaburo Shoten. The catchphrase 'High Blood Pressure' was created by Toyoji
The newspaper advertisement for 'Salomethil' that Toyoji was involved in wins the first Newspaper Advertising Encouragement Award
Established 'Goshi Kaisha Sakuragaoka Laboratory' in Tokyo
Toyoji visits the pharmaceutical industry in Europe and America
Launch of Vitamin E agent 'Ubera'
Established Nippon Eizai Co., Ltd. in Honjo Town, Saitama Prefecture
Gōshi Kaisha Sakuragaoka Laboratory and Nippon Eizai Co., Ltd. merged on an equal footing to become Nippon Eizai Co., Ltd.
The contraceptive 'Sanpoon Tablets,' which was under research and development against the background of the post-war baby boom, passed the national examination
Launched the high-dose B1 agent 'Chocola BB Tablets'
Established a Taipei branch in Taiwan, listed on the First Section of the Tokyo and Osaka Stock Exchanges, and launched stomach medicine 'Sakuron' and 'Sakuron Tablets'
Opened Kawashima Factory in Gifu Prefecture. Toyotsugu Naito became chairman, and Yuji Naito became president
Toyotsugu Naito resigned as representative director and chairman and became an honorary director
Opened Japan's first 'Pharmaceutical Museum' in Gifu Prefecture
The first oil shock caused by the Middle East war broke out
Established pharmaceutical sales companies in Malaysia and the Philippines. Launched the metabolic inotropic agent 'Noykinon'
Launched the natural vitamin E agent 'Yuburex' in Japan
Age 89
Established a company in Singapore for pharmaceutical sales support and management services
Established a sales company for chemicals and pharmaceutical machinery in California, USA. Opened the Misato Factory in Saitama Prefecture and introduced a large automatic sugar coating machine
Established Eisai Chemical Co., Ltd. for active pharmaceutical ingredient manufacturing
Launched the gastric ulcer treatment 'Serbex' in Japan
Started sponsoring the Medical Merit Award (until 2015)
Yūji Naitō assumes the chairmanship. Haruo Naitō becomes president
Established a pharmaceutical sales company in Hong Kong, and an expatriate office and a joint venture company in China. Celebrated the 50th anniversary of founding
Established corporate philosophy and HHC (Human Healthcare)
Research institute completed in London, UK, with Princess Anne attending the ceremony
Established pharmaceutical sales companies in the US, UK, and Germany
Established sales and manufacturing companies in Paris, France, and Suzhou, China. Also established a generic pharmaceutical company
Established a life sciences research institute in Kobe. Established a sales company in Korea. Completed formulation research and production facilities in the US. Launched the Alzheimer's drug 'Aricept'
Launched 'Aricept' in France. Launched 'Pariet' in the UK and Germany
Launched 'Acefex' in the US. Launched 'Aricept' in Japan
Started the 'Millennium Plan'
Transitioned to a committee-established company, established a European holding company, and established a sales company in India
Established sales companies in Italy, Switzerland, and Sweden. Clarified corporate philosophy. Yūji Naitō passed away
Established a sales company in Australia. Acquired the oncology drug 'Ligand'
Established a production company in the UK. Acquired a biotech venture. Established research and production company in India. Established a sales company in Belgium
Launch of the rheumatoid arthritis treatment 'Humira' in Japan
Establishment of sales company in Austria, opening of European Knowledge Center, opening of Eisai Knowledge Center India. Building a global research and development system
Completion of Koishikawa Knowledge Center. US launch of the anticancer drug 'Harvoni'
The Great East Japan Earthquake occurred. Initiation of the 6th Mid-term Strategy 'Hayabusa'. Establishment of sales companies in Brazil and Mexico
London Declaration, Haruo Naito appointed President of the Japan Pharmaceutical Manufacturers Association. European launch of the antiepileptic drug 'Fycompa'
Establishment of a sales company in Moscow, Russia. Participation in development support fund. Providing lymphatic filariasis treatment drug free of charge to WHO
'Fycompa' launched in the US. Establishment of a holding company in China
Launch of the anticancer drug 'Lenvima' in the US, Japan, and Europe. Acquisition of Liaoning Tianyi Biological Pharmaceutical in China
Start of the 7th Mid-term Management Plan 'EWAY2025'. Establishment of Gastroenterology Specialty Pharma. Japan launch of 'Ficonpa'
Participation in non-communicable disease countermeasures. Support for lymphatic filariasis. Contribution to fund. Expansion of Alzheimer’s treatment collaborations
Strategic alliance agreement for 'Lenvima'. Full-scale operation of the Suzhou factory in China. Launch of 'Lenvima' in China
Full operation of US G2D2. Japan launch of Parkinson's treatment 'Exfina'. Launch of 'Ficonpa' and 'Harvoni' in China
WHO declaration of COVID-19 pandemic. Launch of self-check tool 'NOU KNOW'. US and Japan launch of sleep disorder drug 'Deebigo'. Establishment of bases in China and Vietnam
Start of the 8th Mid-term Strategy 'EWAY Future & Beyond'. US approval of 'Aduhelm'. Expansion of partnership agreements. Hosting of the Tokyo Olympics. 80th anniversary of founding
Change of partnership agreement for 'Aduhelm'. Subsidiarization. Establishment of sales company in South Africa. Public-private partnership signing for tropical disease control. Launch of research system
US approval and launch of 'Leqembi'. Contribution to fund. Full approval of 'Leqembi'. Establishment of digital business company. Japan launch of 'Rekenbi'
Eisai has published its Value Creation Report 2026, providing information to deepen dialogue with stakeholders. The report describes the practice of the company's corporate philosophy, initiatives in four priority areas, and its medium- to long-term value creation story.
To mark World Environment Day 2026, the Eisai Group held participatory activities to deepen employees’ understanding of environmental issues. Sites across Japan organized initiatives and seminars focused on climate change, aiming to raise environmental awareness.
Eisai works to improve access to medicines in developing countries and develop treatments for tropical diseases. As part of this global health work, its Sustainability Department held a summer school program where children learned about global health through quizzes and games covering tropical diseases, sanitation and infection prevention. The children asked questions and shared their own ideas.
Miwa Shindo, an Eisai employee, visited São Tomé and Príncipe for the first time and shares the appeal of the country and impressions of its people. The visit was to attend a meeting aimed at eliminating lymphatic filariasis. The report also provides basic information about São Tomé and Príncipe and reflections from the trip.
In the 2026 ESG index selection, Eisai was once again included in all six domestic equity ESG indices adopted by the Government Pension Investment Fund of Japan. It also retained its inclusion in global ESG indices such as the FTSE4Good Index Series and MSCI Selection Indexes.
In the GHIT Fund's "SDGs Talk" series, Eisai's development of a therapeutic drug for mycetoma was introduced. The discussion touched on the relationship between poverty and infectious diseases, as well as Eisai's initiatives.
Eisai Co., Ltd. has issued the "Human Capital Report 2026", which summarizes its initiatives and KPIs related to human capital. The report, themed around stories of challenge and growth, highlights employees' challenges and growth through failures and conflicts. It also includes initiatives for cross‑organizational and cross‑industry collaboration and learning.
The final surveillance for controlling lymphatic filariasis in São Tomé and Príncipe has begun. Eisai has been supporting since 2018 through free provision of DEC tablets, and about 30 people including government officials and WHO personnel attended the meeting.
The final surveillance for the control of lymphatic filariasis in São Tomé and Príncipe has begun, and Eisai is supporting it through free provision and other means.
Eisai Co., Ltd. has been selected as a constituent stock of the SOMPO Sustainability Index for 2026, and is working on long-term social contribution and sustainability strategies.