NEWS – Britain approves world’s first gene therapy Casgevy for sickle cell disease and thalassemia

CASGEVY

By Vertex Pharmaceuticals (Europe) Ltd. and CRISPR Therapeutics.

How does Casgevy work?

• Edits a patient’s own blood stem cells to produce high levels of Fetal hemoglobin

*Fetal hemoglobin – healthy, oxygen-carrying form of hemoglobin + produced during fetal development + shuts down soon after birth

• Increase of Fetal hemoglobin reduces the mildness of Sickle cell disease improving the outcome
• Tech is based on CRISPR/Cas9 enzyme which makes a cut at a specific spot in a gene called BCL11A which disables a DNA brake on the production of fetal hemoglobin

Benefits

• Cost effective
• Reduce the dependency on Bone Marrow

ADDITIONAL INFO

WHAT IS CRISPR?

• Way to change specific areas of DNA
• Learnt from bacteria, which use it as an immune system to fend off attacks by viruses
• A CRISPR editing system has two parts: a “guide RNA” sequence and a pair of molecular “scissors.” The guide sequence leads the scissors to a specific spot on the double helix and the scissors cut the strand of DNA there, inactivating that gene

WHAT IS SICKLE CELL DISEASE? WHAT IS BETA THALASSEMIA?

1. Sickle Cell Disease (SCD):
   • Cause: Mutation in the HBB gene, leading to the production of abnormal hemoglobin known as hemoglobin S (HbS).
   • Effect: Cause red blood cells to become rigid and take on a characteristic “sickle” shape, which can lead to various complications, including pain, anemia, and organ damage.
2. Beta Thalassemia:
   • Cause: Mutations in the HBB gene that result in reduced or absent production of normal hemoglobin (beta-globin).
   • Effect: The reduced or absent beta-globin leads to an imbalance in the production of alpha and beta chains, causing an excess of alpha chains that can damage red blood cells and lead to anemia