Recombinant, live attenuated, measles virus vector based vaccines are being developed by Themis Bioscience (a subsidiary of Merck and Co) for prevention of infectious diseases, primarily virus infections. The vaccines, which are designed using Themaxyn™ vector technology licensed from Institut Pasteur, are intended for use in travellers as well as for individuals in endemic developing countries. The Themaxyn™ platform is based on an attenuated measles virus vector, based on based on the backbone of the measles Schwarz virus strain and which carries difficult-to-present antigens as ‘transgenes’. Themaxyn™ vaccines are designed to target the antigens directly to macrophages and dendritic cells, resulting in a potent antigen-specific immune responses, whilst avoiding immune responses to the vector. Preclinical development is underway for vaccine candidates against dengue, respiratory syncytial virus, norovirus infections, cytomegalovirus and Middle East respiratory syndrome coronavirus vaccines.
A lead candidate MV LASV for Lassa fever entered into clinical development [see ADIS Insight Drug profile 800056007].
Vaccine for the prevention of chikungunya infections was advanced into clinical development [see ADIS Insight Drug profile 800040811].
Earlier, preclinical development of a Yellow fever virus vaccine was underway; however, the candidate is not listed in Themis Bioscience's pipeline, August 2016, and therefore the development appears to be discontinued.
Themis Bioscience intends to out-license its vaccines once proof of concept has been established  .
As at July 2018, no recent reports of development had been identified for preclinical development in Dengue in Austria (Parenteral).
In June 2020, Themis Bioscience was acquired by Merck & Co  .
In March 2018, Coalition for Epidemic Preparedness Innovations (CEPI) and Themis Bioscience entered a partnership for the development of vaccines against Lassa fever and Middle East respiratory syndrome coronavirus. Under the partnership, CEPI made an investment of $US37 500 000 in Themis Bioscience. The company will be responsible to apply its technology platform to discover the vaccines for Lassa fever and Middle East respiratory syndrome coronavirus and to advance the candidates up to human proof-of-concept and safety studies. Further details of the collaboration were not disclosed. 
Key Development Milestones
The proof of concept preclinical trial of MERS vaccine candidate is ongoing, against middle east respiratory syndrome, caused by the MERS-corona virus (Themis Bioscience pipeline, August 2019).
The company is also planning to advance its dengue fever vaccine candidate into clinical development. The development of the vaccine candidate will be funded by the Global Health Innovative Technology, until the completion of phase I development (Themis Bioscience pipeline, August 2016).
Preclinical development is underway for respiratory syncytial virus and norovirus vaccine candidates (Themis Bioscience pipeline, August 2016).
As of August 2019, cytomegalovirus vaccine candidate completed preclinical proof of concept trial (Themis Bioscience pipeline, August 2019). Previously, Themis Bioscience, in collaboration with the Institut Pasteur, was conducting early research development of its cytomegalovirus vaccine candidate (Themis Bioscience pipeline, August 2016).
In December 2016, Themis Bioscience reported the establishment of GMP manufacturing with an aim to initiate phase I trials in early 2017. The company initiated a toxicity preclinical study and tested vaccine candidates in animal models  .
In January 2018, Themis Bioscience closed a Series C round totalling €10 million. The proceeds will be used to advance Themis’ clinical and preclinical vaccine development programmes  .
The Themaxyn™ vaccine technology is patent-protected.