How Genentech's Antibodies Stop Tumor Blood Vessel Growth

A Genentech patent for specific lab-made antibodies that block a protein called VEGF, effectively starving tumors of the blood supply they need to grow.

What it covers

This patent describes a method for stopping angiogenesis, which is the process of creating new blood vessels. Tumors often use a protein called VEGF to signal the body to grow new vessels to feed them. The patent claims a specific humanized antibody designed to bind to VEGF with high affinity, effectively neutralizing it. By blocking this signal, the antibody prevents the proliferation of endothelial cells, which are the cells that line blood vessels, thereby inhibiting tumor growth.

What it doesn't cover

• —Does not cover antibodies that bind to VEGF with a lower affinity than 1x10^-8 M.
• —Does not cover antibodies that lack the specific amino acid sequences defined in the CDR regions.
• —Does not cover non-humanized antibodies or other types of VEGF inhibitors like small molecule drugs.
• —Does not cover general methods of cancer treatment that do not specifically target the VEGF pathway.

The clever bit

The innovation lies in the specific humanization of the antibody sequences, which allows the drug to be effective in humans without triggering a massive immune rejection response, while maintaining high binding affinity to the target protein.

Why it matters

This technology is fundamental to modern oncology and ophthalmology. It provided the intellectual property foundation for Avastin (bevacizumab), a blockbuster drug used to treat various cancers and eye conditions like macular degeneration. It represents a shift toward targeted biological therapies rather than broad-spectrum chemotherapy.

Real-world examples

• 1.Avastin (bevacizumab)
• 2.Lucentis (ranibizumab)