Cd19-specific Immunotoxin and Treatment Method

Simple SummaryContent extracted from patent full text and abstract with AI.

This patent describes a specially engineered immunotoxin designed to selectively target and kill B-lineage cells that express the CD19 antigen, such as those found in certain cancers and autoimmune diseases. The immunotoxin combines a CD19-specific antibody fragment (lacking the Fc region to reduce side effects) with a modified bacterial exotoxin A, linked together by a peptide linker that is resistant to being broken down outside target cells. When administered, the immunotoxin binds to CD19-positive cells, is taken up by them, and delivers the toxin to induce cell death—primarily through apoptosis. This approach allows for highly targeted therapy with minimized off-target toxicity.

Use CasesContent extracted from patent full text and abstract with AI.

• Treatment of cancers associated with malignant B-lineage cells, including chronic lymphocytic leukemia (CLL), Non-Hodgkin lymphoma (NHL), and acute lymphoblastic leukemia (ALL).
• Therapy for autoimmune diseases where B-cells play a role, such as multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus (SLE).
• Research tool for selectively eliminating CD19-expressing cells in laboratory or preclinical studies.
• Potential development of similar immunotoxins for targeting other cell-surface antigens in various cancers.

BenefitsContent extracted from patent full text and abstract with AI.

• High specificity for CD19-expressing B-cells, minimizing harm to non-target cells.
• Reduced systemic toxicity due to the toxin's activation primarily inside target cells, not in circulation.
• Ability to induce apoptosis (programmed cell death) in target cells, leading to effective cancer cell elimination.
• Minimized immune reactions compared to full antibodies, because the Fc region is removed.
• Potential to treat diseases difficult to address with conventional chemotherapy or immunosuppressive therapy.
• Demonstrated efficacy at very low (nanomolar) concentrations, enabling lower dosing and potentially fewer side effects.
• Versatility for combination therapy with other anti-cancer or immunosuppressive agents.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

An immunotoxin for use in, and a method for treating a subject having a cancer associated with malignant B- lineage cells or an autoimmune condition, are disclosed. The immunotoxin includes (a) an anti-CD19 antibody lacking an Fc fragment, (b) a modified exotoxin A protein having both Domains II and III, but lacking Domain I, and (c) a peptide linker joining the C-terminal end of the antibody to the N-terminal end of the modified exotoxin A protein. The linker is substantially resistant to extracellular cleavage. The modified exotoxin A protein may be further modified to include a C-terminal KDEL sequence (SEQ ID NO: 6) that promotes transport of the protein to the endoplasmic reticulum of cells that have taken up the immunotoxin.