We are committed to transforming the lives of patients with serious diseases through CRISPR/Cas9 gene editing

CRISPR/Cas9 is a gene-editing technology that can be used to modify, delete or correct DNA.

Our initial clinical studies are in β-thalassemia and sickle cell disease (SCD), where we are editing the DNA of patients' own stem cells with the goal of generating healthy red blood cells.

To learn more about the trials of CTX001 in β-thalassemia and sickle cell disease please follow the link to If you are a patient with β-thalassemia or sickle cell disease you can also speak to your hematologist to learn whether you may be able to participate in these trials.

For more information about all of the diseases we are seeking to treat with CRISPR/Cas9, please visit our programs page here.

What is CRISPR/Cas9 gene editing and how does it work?

To explain what CRISPR/Cas9 is, it is first helpful to understand a bit about the genetic information in our cells.

Our bodies are made up of trillions of cells. Each cell contains a substance called DNA that carries our genetic information. DNA is important because it tells the cell how to function within the body (like a mini instruction manual). The complete set of instructions for our body is known as our genome.

Changes in DNA can affect our health in either a positive or negative way. Researchers are now trying to find ways to make positive changes to DNA to treat disease. This is called genome or gene editing, and CRISPR/Cas9 is one example of a technology that does this. You may often hear it simply referred to as CRISPR (pronounced ‘crisper’). CRISPR/Cas9 consists of two parts called guide RNA and Cas9.

Guide RNA is a substance similar to DNA. Its main job is to locate the DNA that needs changing and stick to it.

Cas9 is a protein that acts as a precise DNA-editing tool. Its role is to edit the DNA at the precise location that the guide RNA has stuck to.

Once the DNA is edited, the cell should now contain a corrected set of instructions to form healthy cells.

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