How Genentech Created Antibodies to Stop Tumor Growth

A 1997 patent describing a specific humanized antibody designed to block VEGF, a protein that helps tumors grow their own blood supply.

What it covers

This patent describes the genetic blueprints for a specialized antibody that targets Vascular Endothelial Growth Factor (VEGF). By binding to VEGF, the antibody prevents it from signaling endothelial cells to multiply, effectively starving tumors of the blood supply they need to expand. The patent specifically claims the DNA sequences required to produce these humanized antibodies, which are designed to be less likely to trigger an immune rejection in human patients compared to purely mouse-derived versions.

What it doesn't cover

• —Does not cover all possible anti-VEGF antibodies, only those containing the specific amino acid sequences defined in the claims.
• —Does not cover methods of treating specific diseases, as the claims focus on the nucleic acids and the production process.
• —Does not cover naturally occurring antibodies found in non-human animals.
• —Does not cover generic antibody production techniques that do not utilize these specific sequences.

The clever bit

The inventors successfully 'humanized' a mouse antibody by grafting its specific antigen-binding loops (CDRs) onto a human antibody framework, maintaining high binding affinity while minimizing the risk of the patient's immune system attacking the drug itself.

Why it matters

This patent is a cornerstone of modern anti-angiogenic therapy. It provided the intellectual property foundation for Avastin (bevacizumab), one of the most commercially successful and clinically significant cancer drugs in history. It changed how we treat metastatic cancers by shifting focus from killing tumor cells directly to cutting off their life support.

Real-world examples

• 1.Avastin (bevacizumab)