Targeted Cancer Drugs Using Antibodies and Polymer Scaffolds

This patent describes a new way to deliver powerful cancer drugs directly to tumor cells using a specific antibody attached to a special polymer, aiming to reduce side effects.

What it covers

This patent describes a special molecule called an antibody-drug conjugate (ADC) designed to deliver therapeutic agents, which are powerful drugs, directly to cancer cells. The ADC works by using an isolated antibody that specifically attaches to a protein called SLC34A2, also known as NaPi2b, found on the outside of certain tumor cells (Claim 1). Connected to this antibody are one or more "D-carrying polymeric scaffolds." These scaffolds are made of a material called poly(1-hydroxymethylethylene hydroxymethyl-formal) (PHF) and hold the therapeutic agents (D) (Claim 1). The drugs are attached to the scaffold using a "biodegradable bond" (Claim 1), meaning the bond breaks inside the tumor cell, releasing the drug to do its work. For example, this system could deliver a chemotherapy drug directly to a lung cancer cell that has the NaPi2b protein on its surface.

What it doesn't cover

• —Does not cover antibody-drug conjugates that target proteins other than SLC34A2 (NaPi2b).
• —Does not cover ADCs that use a polymeric scaffold different from poly(1-hydroxymethylethylene hydroxymethyl-formal) (PHF).
• —Does not cover ADCs where the therapeutic agent is not released via a biodegradable bond as described in the claims.
• —Does not cover ADCs where the total number of polymer scaffolds connected to the antibody is more than 10 (Claim 1).
• —Does not cover ADCs where the antibody does not have the specific amino acid sequences for its binding regions (CDRs) as detailed in Claim 2.

The clever bit

The innovation lies in combining a highly specific antibody that targets the NaPi2b protein on cancer cells with a unique PHF polymeric scaffold. This scaffold can carry multiple therapeutic agents and release them in a controlled manner via biodegradable linkers, ensuring the drug is potent where needed and less toxic elsewhere.

Why it matters

Targeted drug delivery, especially for cancer, is crucial because it aims to kill cancer cells while sparing healthy ones, reducing severe side effects. This patent from Mersana Therapeutics focuses on improving this targeting by using a specific antibody and a unique polymer to deliver drugs more effectively. Such advancements are vital for developing new treatments for difficult-to-treat cancers, potentially offering better outcomes for patients.

Real-world examples

• 1.Mersana Therapeutics' upifitamab rurxolumab (UPK) which targets NaPi2b
• 2.Antibody-drug conjugates (ADCs) for ovarian cancer treatment
• 3.Targeted therapies for non-small cell lung cancer
• 4.Next-generation ADCs with polymer-drug conjugation platforms