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.
Original patent title: “Napi2b-targeted antibody-drug conjugates and methods of use thereof”
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. Owned by Mersana Therapeutics with 38 claims and 3 forward citations, and it is expected to expire in 2041.
Coverage
What does this patent actually cover?
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 (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 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.
The gap
What does this patent NOT 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 claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →.
- Does not cover ADCs where the total number of polymer scaffolds connected to the antibody is more than 10 (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover ADCs where the antibody does not have the specific amino acid sequences for its binding regions (CDRs) as detailed in ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 2.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
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.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Mersana Therapeutics' upifitamab rurxolumab (UPK) which targets NaPi2b
Antibody-drug conjugates (ADCs) for ovarian cancer treatment
Targeted therapies for non-small cell lung cancer
Next-generation ADCs with polymer-drug conjugation platforms
Why it matters
The bigger picture
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.
Filed
January 20, 2021
Market context
Who's building on this
Companies in this space
Mersana Therapeutics Inc., the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is actively developing antibody-drug conjugates using this technology, with their lead candidate upifitamab rurxolumab (UPK) targeting NaPi2b. Other major pharmaceutical companies and biotech firms are also investing heavily in the broader ADC space, continuously seeking to improve targeting, drug payload, and linker stability for various cancer indications.
Market impact
This patent contributes to the rapidly growing market for antibody-drug conjugates, a significant segment of oncology therapeutics. By offering a novel approach to targeted drug delivery, it enables the development of new drug candidates that aim to overcome limitations of earlier ADCs, such as off-target toxicity or insufficient drug delivery. This technology could lead to more effective treatments for cancers expressing the NaPi2b protein, potentially expanding treatment options and improving patient outcomes in this critical area of medicine.
Claim 1 — Plain English
What this patent 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.
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.
What it does not 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.
Patent timeline
Application submitted to the patent office
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
12/40
Early citations
Claim breadth
20/20
Very broad protection
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$144K – $461K
Midpoint $288K · 14.4 yr remaining · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
38 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Bodyak, N. D., Park, P. U., Yurkovetskiy, A. V., POLING, L. L., Bergstrom, D. A., & Lowinger, T. B. Targeted Cancer Drugs Using Antibodies and Polymer Scaffolds (U.S. Patent No. 20,210,301,031). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/20210301031/napi2b-targeted-antibody-drug-conjugates-and-methods-of-use-thereof
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Targeted Cancer Drugs Using Antibodies and Polymer Scaffolds cover?
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.
Who owns patent US 20210301031?
This patent is owned by Mersana Therapeutics.
When does this patent expire?
This patent is expected to expire on January 20, 2041, when the invention enters the public domain.
What is patent US 20210301031 cited by?
This patent has been cited by 3 later patents that build on its ideas.
What problem does this patent solve?
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.
What does this patent NOT cover?
Does not cover antibody-drug conjugates that target proteins other than SLC34A2 (NaPi2b).
Patent monitoring