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.

What it 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.

What it doesn't 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.

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.

Real-world examples

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