You can freely build on How to Build Smaller, Synthetic Antibody-Like Molecules for Medicine

What this patent covers

The patent details a method for creating a single-chain polypeptide that acts like an antibody but is much smaller. It achieves this by taking the two key binding parts of a natural antibody—the light chain variable region and the heavy chain variable region—and connecting them with a flexible peptide linker. This creates one continuous protein chain rather than the complex, multi-part structure of a natural antibody. In practice, this molecule can be conjugated to a therapeutic agent, such as a drug or toxin, to target specific cells, like cancer cells, while ignoring healthy ones.

What is now free to use

All 1 claims of US 5455030 are in the public domain. Specifically:

The 1 dependent claim add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover full-sized, naturally occurring antibodies with two heavy and two light chains.

• Does not cover binding molecules that lack a peptide linker to connect the variable regions.

• Does not cover non-protein-based targeting molecules.

• Does not cover the specific therapeutic agents themselves, only the method of using the single-chain molecule as a delivery vehicle.

Who is building on this today

Major pharmaceutical companies like Amgen, Roche, and AstraZeneca utilize variations of single-chain binding technology to develop targeted cancer therapies. The fundamental concepts established here are now standard tools in protein engineering labs globally.

Products built on expired version of this technology

How to cite this patent in your documentation

Enzon Labs Inc. US Patent 5455030. Immunotheraphy using single chain polypeptide binding molecules. Granted 1995, expired 2013. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.