US20260286321
2026-09-24
Chemistry; metallurgy
C12N9/127
The patent application introduces self-amplifying RNA (saRNA) constructs designed for superior protein expression, extended durability, minimized immunogenicity, and consistent expression of multiple therapeutic proteins. These constructs are composed of a 5′ untranslated region, alphavirus-derived non-structural protein genes, therapeutic protein-encoding genes, a 3′ untranslated region, and modified nucleosides. The application also describes dual construct systems and multivalent polycistronic constructs capable of encoding various combinations of chimeric antigen receptors (CARs), cytokines, and other immunomodulatory molecules.
The saRNA constructs leverage the unique properties of alphavirus genomes, known for encoding non-structural proteins that form an RNA-dependent RNA polymerase complex, enhancing RNA template amplification and protein expression. This addresses limitations of conventional mRNA approaches, which typically suffer from short expression durations and heterogeneous protein production. The novel constructs aim for prolonged and homogeneous expression, overcoming challenges in applications requiring sustained or multi-protein expression.
The constructs are tailored for engineering immune cells to treat cancer, inflammatory conditions, and infectious diseases. Unlike permanent genetic integration methods, which pose safety risks, these saRNA constructs offer a transient expression profile that allows for effective depletion of pathogenic cells while enabling safe immune system recovery. This transient nature provides a better safety profile, particularly in chronic inflammatory conditions where permanent modifications could lead to severe side effects.
The application details various embodiments of saRNA constructs, including those with point mutations in non-structural proteins to optimize performance. The constructs can derive sequences from a wide range of viruses, enhancing their adaptability and effectiveness across different cell types. Specific constructs like ABLE-003 to ABLE-011 are highlighted, each offering unique capabilities for therapeutic applications.
To further improve performance, the saRNA constructs incorporate modifications in the 5′UTR and 3′UTR regions to enhance transcription, translation, and stability. Additionally, modified nucleotides such as pseudouridine and N1-methyl-pseudouridine are used to reduce immunogenicity and increase translation efficiency. These enhancements make the constructs suitable for a wide range of therapeutic proteins, including enzymes, hormones, and gene-editing enzymes.