Compositions and methods for treating cancer with anti-CD33 immunotherapy

Inventors

ORENTAS, RimasSchneider, DinaDropulic , BoroDimitrov, Dimiter S.Zhu, Zhongyu

Assignees

Lentigen Technology IncUS Department of Health and Human Services

Publication Number

US-11464801-B2

Publication Date

2022-10-11

Expiration Date

2038-03-23

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Abstract

Chimeric antigen receptors containing CD33 antigen binding domains are disclosed. Nucleic acids, recombinant expression vectors, host cells, antigen binding fragments, and pharmaceutical compositions, relating to the chimeric antigen receptors are also disclosed. Methods of treating or preventing cancer in a subject, and methods of making chimeric antigen receptor T cells are also disclosed.

Core Innovation

The invention provides chimeric antigen receptors (CARs) containing human CD33 antigen binding domains, as well as nucleic acids encoding these CARs, recombinant expression vectors, host cells expressing these receptors, antigen binding fragments, and pharmaceutical compositions. These CARs exhibit high surface expression on transduced T cells, a high degree of cytolysis, and support transduced T cell expansion and persistence in vivo. Methods for treating or preventing cancer by administering these CARs or CAR-expressing cells are described.

CD33 is a myeloid differentiation antigen highly expressed on myeloid progenitor cells and on the majority of acute myeloblastic leukemias (AML). Existing therapies targeting CD33-positive malignancies, including antibody-drug conjugates and bispecific T-cell engaging antibodies, have faced limitations due to toxicity and suboptimal efficacy. The disclosed CARs seek to overcome these challenges by using fully human antigen binding domains to improve CAR T-cell persistence, efficacy, and safety, thus addressing the urgent need for safer, efficacious, and durable treatments for AML and other cancers expressing CD33.

Claims Coverage

The patent includes independent claims focused on isolated chimeric antigen receptors (CARs) comprising specific CD33 antigen binding domains, nucleic acids encoding these CARs, and methods of making CAR-expressing T cells.

Chimeric antigen receptor with CD33 binding domain and intracellular signaling domains

An isolated CAR comprising, from N-terminus to C-terminus: (i) at least one extracellular antigen binding domain that binds CD33 comprising a heavy chain variable region with amino acid sequence SEQ ID NO: 2 or 4, or a single chain fragment variable (ScFv) domain selected from SEQ ID NOs: 6, 8, 10, and 12; (ii) a transmembrane domain from selected T-cell receptor chains or costimulatory proteins; (iii) at least one costimulatory domain with functional signaling domains from specified proteins including OX40, CD28, 4-1BB, among others; and (iv) an intracellular signaling domain comprising functional domains selected from 4-1BB, CD28, and CD3 zeta signaling domains.

Chimeric antigen receptor transmembrane domain embodiment

The transmembrane domain of the CAR comprises the amino acid sequence of SEQ ID NO: 27 or sequences with high identity (85-99%) to SEQ ID NO: 28.

Linker or spacer domain connecting binding and signaling domains to transmembrane domain

The extracellular CD33 antigen binding domain and the intracellular signaling domain, or both, are connected to the transmembrane domain by a linker or spacer domain derived from extracellular domains of CD8, TNFRSF19, IgG4, or CD28.

Method of making CAR-expressing cells by transduction

A method of making a cell comprising transducing a T cell with a vector encoding the CAR described above, having the specified CD33 binding domain, transmembrane domain, costimulatory domain, and intracellular signaling domain.

Method of generating RNA-engineered cells

A method of generating a population of RNA-engineered cells by introducing in vitro transcribed or synthetic RNA encoding the CAR described above into a cell, with the specified binding, transmembrane, costimulatory, and intracellular signaling domains.

The claims comprehensively cover novel CARs with fully human CD33 binding domains linked to defined transmembrane, costimulatory, and intracellular signaling domains, together with methods for producing CAR-expressing cells using these constructs. These inventive features improve CAR expression, functionality, and persistence for treating CD33-associated cancers.

Stated Advantages

The CARs exhibit high surface expression on transduced T cells.

The CARs demonstrate a high degree of cytolysis against CD33-positive tumor cells.

The CAR-expressing T cells show enhanced in vivo expansion and persistence.

Use of fully human CD33 antigen binding domains prevents anti-CAR immune responses, improving CAR T cell persistence and function.

The invention allows tuning CAR affinity to improve specificity and reduce off-target toxicity.

Documented Applications

Treatment or prevention of cancer in subjects, including hematological cancers such as acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), lymphoma, mantle cell lymphoma, non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma, multiple myeloma, and solid tumors.

Generation of genetically engineered T cells expressing CD33-targeting CARs for immunotherapy.

Methods for diagnosing a disease, disorder, or condition associated with CD33 expression by detecting binding of CD33 antibodies or fragments.

Blocking CD33-dependent T cell inhibition and altering the tumor microenvironment to inhibit tumor growth.

Inhibition, suppression, or prevention of immunosuppression of an anti-tumor immune response by administering anti-CD33 antibodies or CAR T cells.

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