Naobios and Tokyo Metropolitan Institute of Medical Science partner to develop new live-attenuated vaccine against mpox
Partnership aims to commercialize new mpox vaccine - with higher level of safety - by 2027
Nantes, France, and Tokyo, Japan, October 23, 2025 – Naobios, a CDMO (Contract Development and Manufacturing Organization) providing bioprocess development and GMP production of clinical batches of virus-based products, and the Tokyo Metropolitan Institute of Medical Science (TMIMS), today announce their collaboration on the development of a new mpox vaccine using a live-attenuated vaccine.
Mpox, also known as monkeypox, is a viral illness caused by the monkeypox virus. It spreads mainly through close contact with an infected person, causing a painful rash, enlarged lymph nodes and fever. It may lead to serious diseases and the development of permanent scars. According to a recent article in Nature, the natural reservoir of the virus could be a forest-dwelling squirrel living in West and Central Africa. The mpox virus causes zoonotic diseases that infect many wild animals and humans, so its eradication is difficult.
A global outbreak began in 2022 and as of March 2025, it has spread to 130 countries, infecting close to 130.000 people and causing more than 280 deaths. Currently two mpox vaccines recommended by the WHO are in use:
One developed in the EU based on the Modified vaccinia virus Ankara (MVA) strain
One developed in Japan based on the LC16m8 strain
This collaboration aims to develop a new vaccine based on a non-replicating highly attenuated vaccinia virus in most mammalian cells. This is of interest due to the extremely low possibility of seeing the emergence of a revertant strain that has mutated and is pathogenic to humans, which ensures a high level of safety.
This partnership with TMIMS is a full project with process development activities, upstream (USP) and downstream (DSP) development, and aseptic GMP production activities using grade A in B suites.
“We are delighted to embark on this new project with TMIMS,” said Eric Le Forestier, managing director of Naobios. “Thanks to our recognized know-how and capabilities in the full development of the bioprocesses involved in the manufacture of viral-based products, paired with TMIMS expertise, we are fully equipped to bring this project forward efficiently.”
The process development activities started this year and should be completed by end of Q3, 2025. For the rest of 2025 and into 2026, the partners will work on manufacturing the first technical batch, mimicking GMP conditions. The production of the GMP batch for phase I clinical trials will take place in mid-2026. The clinical studies spearheaded by TMIMS are planned for the end of 2026 and the beginning of 2027.
About TMIMS
The Tokyo Metropolitan Institute of Medical Science (TMIMS) is dedicated to advancing basic and medical research in order to improve human health and quality of life. Founded in 2011 through the consolidation of three medical institutes, TMIMS is funded by the Tokyo metropolitan government and supports basic research in molecular and cellular biology in areas including genome replication, protein degradation, and infectious and neurodegenerative diseases. TMIMS also supports the development of new technologies in areas such as genome editing, control of neural prostheses and vaccine development, and clinical research in fields such as optimization of nursing care and development of new treatments for psychiatric, neurodegenerative and other diseases. By integrating top-down applied research with bottom-up basic research, one goal of TMIMS is to more efficiently translate basic research results into beneficial treatments for humankind.
www.igakuken.or.jp
About Naobios
Naobios is a Contract Development and Manufacturing Organization (CDMO) providing bioprocess development and offering GMP production of clinical batches of BSL2/BSL3 viral vaccines, oncolytic viruses, challenge agents, viral vectors and exosomes. Naobios joined the Clean Biologics group in 2019.
Having built up 20 years’ experience in bioprocess development, Naobios helps its clients to bring their drug candidates to the clinical stage as rapidly as possible – at the highest level of quality – whilst building on its technical know-how in scalable and industrial processes. With its adaptability and range of skills, the company can lead a project from the initial stages through to completion, with a motivated and dedicated team. Its highly qualified staff have the experience to deal with a wide range of viruses, as well as multiple cell substrate lines.
Naobios is based near Nantes, in Western France.
www.naobios.com