Capricor Therapeutics announces publication engineered exosome platform

Capricor Therapeutics announced the publication of a preclinical study highlighting new advances for its engineered exosome program. The data was published online in bioRxiv and explored the therapeutic potential of Capricor’s proprietary StealthX exosome platform, which generated two vaccine candidates, that independently, and in combination induced a strong immune response against two SARS-CoV-2 proteins, spike and nucleocapsid. Results showed that this multivalent, protein-based vaccine candidate has the potential to achieve potent, longer lasting immunization, broaden reactivity and improve T-cell response with only nanograms of protein without any adjuvant. The data from this study suggests that StealthX could deliver a more potent vaccine with broader immunity than is currently available, by combining the advantages of both mRNA and recombinant protein vaccines into a potentially superior, rapidly generated, low-dose vaccine. The current study used engineered exosomes to express either SARS-CoV-2 spike or nucleocapsid protein on the exosome surface rapidly, a timeframe similar to mRNA vaccines. When administered as a single product, both STX-S and STX-N induced strong immunization with the production of a potent humoral and cellular immune response simultaneously. These effects were obtained with administration of only nanograms of protein without the use of any adjuvant or lipid nanoparticles which further supports the potential safety profile of this product candidate. The study also investigated the combination of STX-S and STX-N, namely STX-S+N, in two independent animal models. Administration of this multivalent, low dose protein-based vaccine resulted in increased, persistent antibody production, potent neutralizing antibodies with cross-reactivity to other variants of concern, and strong T-cell response. The results show efficacy of this multivalent protein-based vaccine for SARS-CoV-2 and suggests that other vaccines or therapeutics could be rapidly developed using the same StealthX platform.