Novel Anti-CD19 Antibodies and Multi-Specific Binding Proteins for Cancer Treatment

Recent breakthroughs in developing anti-CD19 antibodies and multi-specific binding proteins are gaining momentum in the fight against cancer. Researchers from Cullinan Therapeutics Inc. have filed a patent for a groundbreaking invention that combines the potency of BiTE constructs with the convenience of longer-lasting treatments. The new antibodies and proteins have the potential to revolutionize cancer therapy by targeting CD19-expressing cancer cells.

Key Takeaways:

• The invention, patented under number 12428480, utilizes a novel approach to create multi-specific binding proteins that target CD19 and CD3, enhancing T-cell activation against cancer cells.
• The proteins feature a first antigen-binding site that binds to human CD19 with a binding affinity within the range of 5 pM to 1 nM, and a second antigen-binding site that binds to human CD3 with a binding affinity within the range of 0.5 nM to 20 nM.
• The binding sites are linked in various configurations to achieve optimal therapeutic efficacy and in vivo half-life, with the possibility of a half-life extension domain binding to human serum albumin.
• The researchers aim to create a treatment that can overcome the limitations of Blinatumomab, a BiTE construct with a short in vivo half-life, by achieving therapeutic effects through prolonged administration.
• The invention demonstrates a promising step towards developing new and effective cancer therapies, specifically against B-cell hematologic malignancies.

Statistics:

• The invention targets CD19-expressing cancer cells, which account for approximately 95% of T cells.
• The proteins' binding affinities are within the range of 5 pM to 1 nM for CD19 and 0.5 nM to 20 nM for CD3.
• The half-life extension domain binding to human serum albumin offers a dramatic increase in the proteins' in vivo half-life.

Sources:

• Baeuerle, Patrick A. Anti-CD19 antibodies and multi-specific binding proteins. U.S. Patent Number 12428480, filed December 11, 2020, and published online on September 30, 2025.
• Carter et al. (2002) Science, 256: 105-07.
• van Zelm et al. (2006) N. Eng. J. Med., 354: 1901-12.