How to Make Human Erythropoietin (EPO) Using Engineered DNA
This patent describes the specific DNA sequences and methods to engineer cells to produce erythropoietin (EPO), a protein vital for red blood cell production, outside the human body.
Original patent title: “DNA sequences encoding erythropoietin”
This patent describes the specific DNA sequences and methods to engineer cells to produce erythropoietin (EPO), a protein vital for red blood cell production, outside the human body. Granted to Kirin Amgen Inc in 1987 with 36 claims and 346 forward citations.
Key facts
Coverage
What does this patent actually cover?
This patent covers the purified and isolated DNA sequences that carry the instructions for making erythropoietin (EPO), specifically human and monkey EPO (ClaimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → 1, 2, 3). It also claims DNA sequences that code for polypeptides with EPO's biological activity, meaning they can cause bone marrow cells to increase red blood cell production (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 7). The patent further covers the use of these DNA sequences within circular plasmid or viral DNA vectors (Claim 5) and the host cells (like bacteria, yeast, or mammalian cells) that have been transformed or transfected with this DNA to actually produce EPO (Claims 4, 6, 23). For example, a scientist could insert the human EPO DNA sequence into a CHO cell, which would then act like a tiny factory, expressing and producing human EPO.
The gap
What does this patent NOT cover?
- Does not cover the naturally occurring erythropoietin protein found in the human body, only purified and isolated DNA sequences and their products.
- Does not cover methods of treating patients with EPO, only the genetic material and engineered cells for its production.
- Does not cover DNA sequences that produce proteins without the specific biological activity of increasing red blood cell production, hemoglobin synthesis, or iron uptake (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 7).
- Does not cover host cells that are not transformed or transfected with the specific EPO-encoding DNA sequences described.
- Does not cover the discovery of erythropoietin itself, but rather the genetic engineering required to produce it.
- Does not cover DNA sequences that do not hybridize under stringent conditions to the specific sequences disclosed in FIGS. 5 and 6 (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → was isolating and purifying the specific DNA sequences that encode erythropoietin and then demonstrating how to insert these sequences into host cells to make them produce functional EPO. This allowed for the creation of a stable, consistent, and large-scale supply of a critical therapeutic protein.
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
Epoetin alfa (Epogen, Procrit)
Darbepoetin alfa (Aranesp)
Biosimilar EPO products
Recombinant protein manufacturing processes
Why it matters
The bigger picture
Erythropoietin (EPO) is a hormone that stimulates red blood cell production. Before this patent, obtaining sufficient quantities of EPO for medical use was extremely difficult. This patent laid the groundwork for the industrial-scale production of recombinant human EPO, which became a blockbuster drug, revolutionizing the treatment of anemia, particularly in patients with kidney failure or those undergoing chemotherapy.
Filed
November 30, 1984
Granted
October 27, 1987
Market context
Who's building on this
Companies in this space
Amgen, the original assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more → (through its joint venture Kirin Amgen Inc.), remains a dominant player in the erythropoietin market with its original product, Epogen. Other major pharmaceutical companies like Johnson & Johnson (through its subsidiary Janssen Biotech) also produce EPO-based therapies. Many biotech companies are also developing biosimilar versions of EPO, building on the foundational understanding of recombinant protein production.
Market impact
This patent, and the subsequent development of recombinant human EPO, created a new therapeutic category for treating anemia. It enabled the launch of one of the first blockbuster biotechnology drugs, Epogen, generating billions in revenue and profoundly impacting patient care for chronic kidney disease, cancer, and other conditions. It also spurred significant investment and research into recombinant protein technology, establishing a key paradigm for the biopharmaceutical industry.
Claim 1 — Plain English
What this patent covers
This patent covers the purified and isolated DNA sequences that carry the instructions for making erythropoietin (EPO), specifically human and monkey EPO (Claims 1, 2, 3). It also claims DNA sequences that code for polypeptides with EPO's biological activity, meaning they can cause bone marrow cells to increase red blood cell production (Claim 7). The patent further covers the use of these DNA sequences within circular plasmid or viral DNA vectors (Claim 5) and the host cells (like bacteria, yeast, or mammalian cells) that have been transformed or transfected with this DNA to actually produce EPO (Claims 4, 6, 23). For example, a scientist could insert the human EPO DNA sequence into a CHO cell, which would then act like a tiny factory, expressing and producing human EPO.
The clever bit
The novelty was isolating and purifying the specific DNA sequences that encode erythropoietin and then demonstrating how to insert these sequences into host cells to make them produce functional EPO. This allowed for the creation of a stable, consistent, and large-scale supply of a critical therapeutic protein.
What it does not cover
- Does not cover the naturally occurring erythropoietin protein found in the human body, only purified and isolated DNA sequences and their products.
- Does not cover methods of treating patients with EPO, only the genetic material and engineered cells for its production.
- Does not cover DNA sequences that produce proteins without the specific biological activity of increasing red blood cell production, hemoglobin synthesis, or iron uptake (Claim 7).
- Does not cover host cells that are not transformed or transfected with the specific EPO-encoding DNA sequences described.
- Does not cover the discovery of erythropoietin itself, but rather the genetic engineering required to produce it.
- Does not cover DNA sequences that do not hybridize under stringent conditions to the specific sequences disclosed in FIGS. 5 and 6 (Claim 1).
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
High impact
Citation count
40/40
Highly cited
Claim breadth
20/20
Very broad protection
Recency
0/20
Older than 20 years
Assignee scale
20/20
Major company or institution
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
$270K – $864K
Midpoint $540K · expired or expiring · 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.
The original legal language
Original claims
36 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Lin, F. (1987). How to Make Human Erythropoietin (EPO) Using Engineered DNA (U.S. Patent No. 4,703,008). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/4703008/neupogen-g-csf-filgrastim
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 How to Make Human Erythropoietin (EPO) Using Engineered DNA cover?
This patent describes the specific DNA sequences and methods to engineer cells to produce erythropoietin (EPO), a protein vital for red blood cell production, outside the human body.
Who owns patent US 4703008?
Kirin Amgen Inc owns this patent, granted in 1987.
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 4703008 cited by?
This patent has been cited by 346 later patents that build on its ideas.
What problem does this patent solve?
Erythropoietin (EPO) is a hormone that stimulates red blood cell production. Before this patent, obtaining sufficient quantities of EPO for medical use was extremely difficult. This patent laid the groundwork for the industrial-scale production of recombinant human EPO, which became a blockbuster drug, revolutionizing the treatment of anemia, particularly in patients with kidney failure or those undergoing chemotherapy.
What does this patent NOT cover?
Does not cover the naturally occurring erythropoietin protein found in the human body, only purified and isolated DNA sequences and their products.
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