# 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.

- **Patent:** US 4703008
- **Original title:** DNA sequences encoding erythropoietin
- **Owner:** Kirin Amgen Inc
- **Granted:** 1987
- **Status:** Public domain (expired)
- **Times cited:** 346
- **Field:** biotech, pharmaceutical, gene_editing, biotechnology

## What it does

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.

## 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).

## 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.

## Real-world examples

1. Epoetin alfa (Epogen, Procrit)
2. Darbepoetin alfa (Aranesp)
3. Biosimilar EPO products
4. Recombinant protein manufacturing processes

## Why it matters

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.

## 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.

**Full plain-English explainer:** https://patentbrief.org/patent/us/4703008/neupogen-g-csf-filgrastim

**Original patent:** https://patents.google.com/patent/US4703008

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._