Codiak BioSciences, a clinical-stage biopharmaceutical company focused on pioneering the development of exosome-based candidates as a new class of medicines, today announced additional preclinical data from its pan beta-coronavirus vaccine program, which aims to protect against all SARS-CoV-2 variants of concern and potential future strains belonging to the beta-coronavirus family. The data, which are being presented today in a presentation and poster at the Vaccines Summit 2022 in Washington, DC, demonstrate the potential of Codiak’s exoVACC™ vaccine candidate, exoRBD, to protect against multiple known Variants of Concern (VoC) of SARS-CoV-2 and seven coronaviruses from the Sarbecovirus family that are currently in bats and may have a high potential to jump into humans.
“Vaccine and therapeutic development for SARS-CoV-2 has been impressive and life-saving, but the virus continues to mutate to evade vaccine protection. At the same time, there remains the threat that another beta coronavirus or variant of concern could emerge. It’s clear that a vaccine offering comprehensive immunity across a range of coronaviruses would address this urgent need and represents an important advancement in combatting these viruses,” said Sriram Sathyanarayanan, Ph.D., Chief Scientific Officer, Codiak. “Building on the in vivo results we presented over the past year, the data presented today demonstrate the bivalent version of our pan beta-coronavirus vaccine candidate offers broadly protective immunity against known strains of SARS-CoV-2 and has the added benefit of protecting against circulating bat coronaviruses that may have a high potential to make the zoonotic transmission into humans. This suggests that our exosome-based vaccine could limit the virus’ ability to mutate and evade protection. We look forward to our continued partnership with the Coalition for Epidemic Preparedness Innovations (CEPI), which is funding this research, and plan to advance our bivalent exoRBD candidate into IND-enabling studies.”
Codiak’s pan beta-coronavirus vaccine candidate incorporates multiple distinct features to generate comprehensive immunity, notably the use of receptor binding domain (RBD) molecules from coronaviruses to provide broad antibody protection and the integration of highly conserved T cell epitopes that elicit powerful CD8 T cell responses resistant to mutational pressure.
Key conclusions from the preclinical studies presented today include:
- The bivalent version of Codiak’s pan beta-coronavirus vaccine with RBDs from SARS-CoV-2 (Wu) and SARS-CoV-1 generated protective immunity in vivo against multiple SARS-CoV-2 variants and seven circulating bat coronaviruses, including the closely related Pangolin virus;
- Multivalent display of SARS-CoV-2 RBD on exosomes induced greater titers of anti-RBD antibodies and superior neutralization potency than soluble forms of rRBD, highlighting the importance of exosome surface display;
- The loading of a STING agonist onto exoRBD strongly boosts RBD-specific antibody responses with similar levels of neutralizing antibodies as human subjects vaccinated twice with mRNA vaccine, and the antibody responses can last for 10 months or longer;
- The addition of T cell antigens to the exosome-based vaccine elicited CD8+ T-cell response against conserved T-cell epitopes that provided mucosal immunity resulting in maximal protection with minimal lung inflammation following a lethal SARS-CoV-2 challenge.
Codiak’s proprietary and modular vaccine platform, exoVACC, leverages engineered exosomes – naturally occurring, extracellular nanoparticle vesicles – to precisely control antigen display on the surface or in the lumen, in order to deliver antigens, adjuvants and immunomodulators simultaneously and selectively to antigen presenting cells to maximize immune response. The pan beta-coronavirus vaccine construct, developed in collaboration with the Ragon Institute of MIT, MGH and Harvard, carries the receptor-binding domain (RBD) protein of both SARS-CoV-1 and SARS-CoV-2 at high density on the surface of the exosome, combined with structurally constrained, highly conserved T cell antigens expressed in the lumen, and stable loading of a STING agonist as an adjuvant. This design closely resembles the natural viral structures and is amendable to multiple routes of administration, including subcutaneous, intramuscular and intranasal.
Source – GlobeNewsWire