OSE Immunotherapeutics has announced successful completion of its human ex vivo study with CoVepiT, a prophylactic vaccine based on optimized epitopes selected to induce a lasting sentinel T lymphocyte immune response against SARS-CoV-2, the virus that causes COVID-19.

The human ex vivo clinical study, named CoVepiT 1, was conducted in 120 convalescent COVID-19 subjects versus unexposed subjects. It aimed at assessing the memory T cell immune response at a distance from a resolving infection with SARS-CoV-2 adults. The main objective of the study was achieved: the identification of T memory immuno-dominant epitopes after infection with COVID-19 and incorporation in the vaccine composition.

Scientists warn of new SARS-CoV-2 variants spreading rapidly across Europe and bearing mutation in some key targets of the virus, in particular the Spike protein and Nucleoprotein. Based on new analyses of up to 167, 000 different virus sequences taken globally, the OSE Immunotherapeutics bioinformatic team confirmed that mutations did not emerge in the highly stable viral genome region of the 11 targets selected by OSE and that the CoVepiT vaccine continues to cover all initial and novel SARS-CoV-2 strains and variants.

These results from both preclinical and human ex vivo studies as well as the expected emergence of new SARS-CoV-2 variants build a strong basis for supporting the development of CoVepiT as a novel and differentiated COVID-19 vaccine designed against multiple coronavirus targets with vaccinal technology known to induce long-lasting memory T lymphocytes.

“The identification of T memory immuno-dominant epitopes, selected for their high potential for immunogenicity, is a major step to move into clinical testing early 2021. We warmly thank all the subjects included and the clinical teams led by Dr Didier Debieuvre, of the Hospital Center Emile Müller of Mulhouse, and Dr Valérie Heyer, of the Marine Firefighters of Marseille, for their participation in our clinical study and commitment to the COVID-19 vaccine development program. We are also very pleased to be the first company to present a second-generation COVID-19 memory T cell vaccine with potential for protecting future endemic pan-coronaviruses at a scientific congress,” Nicolas Poirier, Chief Scientific Officer of OSE Immunotherapeutics, said.

“Using expertise and knowledge gained from our Memopi? epitope vaccinal technology allowed us to quickly develop a COVID-19 vaccine based on peptides, as part of our T cell-based vaccine platform. This same technology, already in use with Tedopi? in advanced lung cancer, has shown efficacy and good tolerance in this indication and should help accelerate the development process of our COVID-19 vaccine focused on memory CD8 T cell technology,” Alexis Peyroles, Chief Executive Officer of OSE Immunotherapeutics, said.

The CoVepiT program is based on a clinically validated technology now shown to induce tissue-resident memory T lymphocytes (Trm) sentinel response against multiple parts of SARS-CoV-2, suggesting it provides a long-term protective immunity. In addition, this vaccine is designed to anticipate ongoing recurrent virus mutation and evolution, that should reinforce its long-term protective potential.