U.S. FDA approves pair of gene therapies for sickle cell disease

• The U.S. Food and Drug Administration (FDA) recently approved a pair of gene therapies for sickle cell disease.
• The agency approved Lyfgenia from bluebird bio, and Casgevy by Vertex Pharmaceuticals and CRISPR Therapeutics for the illness.
• Both therapies are approved for individuals aged 12 years and older.

CRISPR Gene Editing Technology

• Casgevy utilizes the breakthrough CRISPR gene editing technology, awarded the Nobel Prize in 2020.
• Casgevy edits the faulty gene responsible for sickle cell disease using the patient's own blood stem cells.
• It targets the BCL11A gene, promoting the production of foetal haemoglobin, which does not carry the same abnormalities as adult haemoglobin.

Sickle Cell Disease

• Sickle cell disease is an inherited blood disorder causing pain, organ failure, and premature death.
• Approximately 100,000 people in the US, predominantly Black individuals, are affected by the disease.
• Sickle cell disease results in flawed, sickle-shaped haemoglobin, impairing oxygen transport by red blood cells.
• Sickle cells can clump together, blocking blood vessels and causing severe pain, strokes, and organ failure.

One-Time Treatments

• Both therapies are marketed as one-time treatments, but the duration of their effectiveness is uncertain.
• Doctors express skepticism, preferring to term them "transformative therapy" rather than a cure.
• The only longer-term treatment for sickle cell disease is a bone marrow transplant.

Prelims Takeaway

• Casgevy
• Sickle Cell Disease