BioTech IP Review

Assignee: Legend Biotech Ireland Limited
Patent Number: 12,275,788 B2
Filed: September 10, 2019
Issued: April 15, 2025
Inventors: Yafeng Zhang, Tailan Zhan, Fei Sun, Jian Liu, Qing Zhang, Shu Wu

What This Patent Covers

This patent protects single‑domain antibodies (sdAbs) that specifically bind to CD33 — a cell surface antigen highly expressed on certain hematologic cancer cells such as acute myeloid leukemia (AML). The invention includes:

• Single‑domain antibody molecules targeting distinct epitopes of the CD33 protein.
• Constructs comprising these sdAbs, including chimeric antigen receptors (CARs) and other engineered immune effector formats using the CD33‑specific sdAb as the targeting domain.
• Engineered immune effector cells (e.g., CAR‑T cells or CAR‑NK cells) that include these CD33‑binding sdAb constructs.
• Pharmaceutical compositions, kits, and methods of treating cancer by administering cells or constructs that incorporate the CD33‑targeting sdAb.

These sdAb‑based constructs improve the targeting specificity of immune effector cells toward CD33‑positive malignant cells, which is a key therapeutic strategy in hematologic malignancies.

Why This Patent Is Important

• Supports core cell therapy technology: Legend Biotech’s commercial success centers on advanced immune‑cell therapies such as CAR‑T products. Patents on sdAb constructs expand the company’s intellectual property around next‑generation targeting modules that can be used in CAR designs.
• Broad therapeutic relevance: CD33 is a validated target for AML and other blood cancers — coverage here supports potential therapeutic programs and partnerships beyond the company’s current pipeline.
• Strengthens competitive moat: Having exclusive rights to engineered sdAb constructs for CAR technologies enhances Legend’s position against competitors in engineered cell therapy.
• Pipeline and collaboration value: Legend Biotech frequently develops CAR‑T therapies in collaboration with partners (e.g., with Janssen) — foundational IP like this can be essential for collaborative and licensed programs in multiple myeloma and other cancers.