Naobios and Tokyo Metropolitan Institute of Medical Science Partner to Develop Next-Generation Mpox Vaccine
24 October 2025 | Friday | News
The collaboration will advance a live-attenuated, non-replicating vaccinia-based vaccine with superior safety and stability, with GMP production and clinical trials planned from 2026 to 2027.
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), 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.
