Circular RNA encoding chimeric antigen receptors targeting BCMA

Inventors

Barnes, Thomas • Becker, Amy M. • Goodman, Brian • DUTTA-SIMMONS, Jui

Assignees

Orna Therapeutics Inc

Abstract

Circular RNA, along with related compositions and methods are described herein. In some embodiments, the inventive circular RNA comprises group I intron fragments, spacers, an IRES, duplex forming regions, and an expression sequence. In some embodiments, the expression sequence encodes an antigen. In some embodiments, circular RNA of the invention has improved expression, functional stability, immunogenicity, ease of manufacturing, and/or half-life when compared to linear RNA. In some embodiments, inventive methods and constructs result in improved circularization efficiency, splicing efficiency, and/or purity when compared to existing RNA circularization approaches.

Core Innovation

The invention relates to a precursor RNA polynucleotide and a circular RNA polynucleotide that include 3′ and 5′ group I intron fragments flanking a core functional element. The core functional element comprises a translation initiation element (TIE) comprising an internal ribosome entry site (IRES) and a polynucleotide encoding an amino acid sequence, with the IRES comprising a polynucleotide having at least 95% sequence identity to SEQ ID NO: 1284 or a functional fragment thereof and the encoding polynucleotide having at least 95% sequence identity to SEQ ID NO: 3691 or a functional fragment thereof.

The disclosed circular RNA constructs further comprise the same TIE and coding element, and the disclosure addresses translation initiation and termination elements within the TIE, including stop codons or stop cassettes, untranslated region elements, and synthetic TIE concepts such as aptamer complexes. The described circular RNA platform is tied to therapeutic protein expression, with payload embodiments including CARs, TCRs, cytokines, and dystrophin.

The document also describes circular RNA constructs in the context of evaluation of immunogenicity, expression-related performance, purification, and immunoquiescence, including comparison of circular RNAs produced or purified by negative selection affinity purification versus enzyme purification. Additional construct variations include a dedicated binding site (DBS) for affinity depletion instead of polyA tags, and specific IRES and untranslated region architectures and variants.

Claims Coverage

The consolidated claim coverage includes three independent claim themes. Two themes cover a precursor RNA polynucleotide with 3′ and 5′ group I intron fragments flanking a core functional element containing a TIE with an IRES and a polynucleotide encoding an amino acid sequence, and a circular RNA polynucleotide containing the same TIE and coding element with sequence identity constraints. A third theme covers a cancer treatment method using a composition containing the circular RNA polynucleotide together with a lipid nanoparticle, optionally including a targeting moiety.

Across the independent claims, the central claimed architecture is a TIE with an IRES defined by at least 95% sequence identity to SEQ ID NO: 1284, combined with a polynucleotide encoding an amino acid sequence defined by at least 95% sequence identity to SEQ ID NO: 3691, implemented either in a group I intron-fragment-flanked precursor RNA or in a circular RNA polynucleotide, with a cancer treatment composition claim also present.

Stated Advantages

Documented Applications