Good News: Patients with Thalassemia and Sickle Cell Anemia Begin CRISPR Treatment for the First Time

CRISPR-Cas9 gene-editing technology, considered one of the century’s most important discoveries, continues to bring revolutionary advances in disease treatment. CRISPR -focused CRISPR Therapeutics and Vertex Pharmaceuticals developed CTX001 , a CRISPR-based treatment used for the first time in a patient with beta thalassemia . The first patient with sickle cell anemia has also been enrolled in a clinical trial of CTX001. Let us learn about CTX001 treatment and what it means for us.

What Is Beta Thalassemia?

Beta thalassemia is an inherited hematological (blood) disease caused by mutations in the beta-globin gene. These mutations lead to low or very limited beta-globin protein production. Beta-globin is a basic building block of hemoglobin. Patients with severe beta thalassemia develop anemia and depend on blood transfusions. Repeated transfusions cause iron accumulation, resulting in organ damage and shorter life expectancy.

What Is Sickle Cell Anemia?

Sickle cell anemia is also an inherited blood disease caused by mutations in the beta-globin gene. These mutations cause abnormal hemoglobin production. Abnormal hemoglobin makes red blood cells rigid, abnormally shaped (sickle-shaped), and capable of blocking blood vessels. Patients experience acute pain, acute chest syndromes, and organ damage. All these shorten life expectancy.

CRISPR treatment: what is CTX001?

CTX001 is a CRISPR-based gene therapy. Bone marrow stem cells obtained from patients with beta thalassemia and sickle cell anemia are modified using CRISPR to make red blood cells produce more fetal hemoglobin. Fetal hemoglobin is an oxygen-carrying protein naturally present at birth. It changes to another form in adulthood. CTX001 increases fetal hemoglobin levels, greatly reducing patients’ dependence on transfusions.

In other words, everyone has a second copy of a gene called fetal hemoglobin. This gene switches off after birth and is replaced by the adult form of hemoglobin. CRISPR treatment reactivates this fetal gene.

How Is CTX001 Treatment Performed?

Bone marrow stem cells are collected from patients’ peripheral blood. These stem cells undergo gene modification in the laboratory using CRISPR . The modified stem cells (called CTX001) are returned to the patient. Patients are then monitored to determine whether these gene-modified cells produce healthy blood cells. Finally, the effects of CTX001 cells are monitored through many parameters, and patient follow-up continues.

A single CRISPR treatment is thought capable of achieving complete recovery in these two diseases. Patient results are expected to be announced very soon.

What Is the Status of the Latest Clinical Trials of CTX001?

For beta thalassemia, the CTX001 phase1/2 safety and efficacy clinical trial is ongoing. The study assesses patients aged 18-35 with transfusion-dependent thalassemia (non beta zero / beta zero subgroups) for the safety and efficacy of single-dose CTX001. It is currently conducted at different centers in Canada and Europe. Enrollment in America will also begin during the year.

For sickle cell anemia, the CTX001 phase 1/2 safety and efficacy trial is ongoing. It assesses patients aged 18-35 with sickle cell anemia for the safety and efficacy of single-dose CTX001. It is conducted at different centers in the United States. CTX001 has been included by the United States Food and Drug Administration (FDA) for sickle cell anemia treatment in the accelerated drug designation program. Approvals to begin trials in Canada and other European countries are awaited.

CRISPR / Cas9: what is it?