Using Radioactive Antibodies to Treat B-Cell Lymphoma
A method for treating B-cell lymphoma by using radioactive antibodies to target cancer cells without destroying the patient's bone marrow.
Original patent title: “Radioimmunotherapy of lymphoma using anti-CD20”
A method for treating B-cell lymphoma by using radioactive antibodies to target cancer cells without destroying the patient's bone marrow. Granted to Coulter Pharmaceutical Inc in 1997 with 30 claims and 232 forward citations.
Key facts
Coverage
What does this patent actually cover?
This patent describes a three-step process to treat B-cell lymphoma using antibodies that target the CD20 protein on cancer cells. First, a small amount of radioactive antibody is injected to image the patient and see where the drug goes. Second, a dose of unlabeled antibody is given to block non-tumor binding sites, ensuring the radioactive dose hits the cancer rather than healthy tissue. Finally, a therapeutic dose of radioactive antibody is administered at a level high enough to kill cancer cells but low enough to avoid damaging the bone marrow, which eliminates the need for a stem cell transplant.
The gap
What does this patent NOT cover?
- Does not cover treatments that require hematopoietic stem cell replacement.
- Does not cover antibodies that do not target the CD20 antigen.
- Does not cover non-radioactive immunotherapy methods.
- Does not cover the manufacturing process of the antibodies themselves.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The innovation is the pre-treatment step using unlabeled antibodies to saturate non-specific binding sites, which allows for a more precise and safer delivery of the radioactive payload to the tumor.
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
Bexxar (tositumomab and iodine I-131 tositumomab)
Why it matters
The bigger picture
This patent provided the foundation for Bexxar, a landmark radioimmunotherapy drug. By allowing for effective treatment without the harsh side effects of bone marrow destruction, it changed how doctors approached non-Hodgkin's lymphoma, moving toward more targeted, less toxic therapies.
Filed
September 16, 1993
Granted
January 21, 1997
Market context
Who's building on this
Companies in this space
The technology was pioneered by Coulter Pharmaceutical, which was later acquired by GlaxoSmithKline. Today, the principles of targeted radioimmunotherapy are being expanded by companies like Novartis and various biotech firms focusing on next-generation radioligand therapies.
Market impact
This patent enabled the development of targeted radioimmunotherapy as a viable clinical treatment for lymphoma. It demonstrated that precise dosing could achieve therapeutic results while sparing the patient from the extreme toxicity associated with traditional chemotherapy and bone marrow transplantation.
Claim 1 — Plain English
What this patent covers
This patent describes a three-step process to treat B-cell lymphoma using antibodies that target the CD20 protein on cancer cells. First, a small amount of radioactive antibody is injected to image the patient and see where the drug goes. Second, a dose of unlabeled antibody is given to block non-tumor binding sites, ensuring the radioactive dose hits the cancer rather than healthy tissue. Finally, a therapeutic dose of radioactive antibody is administered at a level high enough to kill cancer cells but low enough to avoid damaging the bone marrow, which eliminates the need for a stem cell transplant.
The clever bit
The innovation is the pre-treatment step using unlabeled antibodies to saturate non-specific binding sites, which allows for a more precise and safer delivery of the radioactive payload to the tumor.
What it does not cover
- Does not cover treatments that require hematopoietic stem cell replacement.
- Does not cover antibodies that do not target the CD20 antigen.
- Does not cover non-radioactive immunotherapy methods.
- Does not cover the manufacturing process of the antibodies themselves.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Strong
Citation count
40/40
Highly cited
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
$73K – $234K
Midpoint $146K · expired or expiring · industry ×1.5
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
30 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Kaminski, M. S., Glenn, S. D., Wahl, R. L., & Butchko, G. M. (1997). Using Radioactive Antibodies to Treat B-Cell Lymphoma (U.S. Patent No. 5,595,721). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/5595721/pcr-thermal-cycler
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 Using Radioactive Antibodies to Treat B-Cell Lymphoma cover?
A method for treating B-cell lymphoma by using radioactive antibodies to target cancer cells without destroying the patient's bone marrow.
Who owns patent US 5595721?
Coulter Pharmaceutical Inc owns this patent, granted in 1997.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 5595721 cited by?
This patent has been cited by 232 later patents that build on its ideas.
What problem does this patent solve?
This patent provided the foundation for Bexxar, a landmark radioimmunotherapy drug. By allowing for effective treatment without the harsh side effects of bone marrow destruction, it changed how doctors approached non-Hodgkin's lymphoma, moving toward more targeted, less toxic therapies.
What does this patent NOT cover?
Does not cover treatments that require hematopoietic stem cell replacement.
Patent monitoring