CASGEVY THERAPY - SCI & TECH
News: Vertex says Casgevy benefit
extends to nearly five years in sickle cell disease
What's in the news?
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The UK drug regulator has approved a gene therapy
called Casgevy for the cure of sickle cell disease and thalassaemia.
Casgevy Therapy:
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It is a CRISPR
Cas9 based gene-edited therapy developed for the treatment of Sickle cell disease and Thalassaemia.
Working:
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Casgevy is a one-time
treatment.
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The treatment involves removing stem cells out of bone marrow from a patient’s blood using
a process called apheresis that filters out the blood for different components.
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CRISPR gene editing technology is then used in a
laboratory to edit the faulty gene.
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The edited cells are then infused back into the
patient, allowing the body to produce functioning haemoglobin.
Target Gene:
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A gene called BCL11A
which is crucial for switching from foetal to adult haemoglobin is targeted by
the therapy.
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Foetal haemoglobin which is naturally present in
everyone at birth, does not carry the same abnormalities as adult haemoglobin.
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The therapy uses
the body’s own mechanisms to start producing more of this foetal
haemoglobin alleviating the symptoms of the two conditions.
Challenges:
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High cost is one of the biggest limitations of gene
therapies.
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Absence of local manufacturing facilities which means that the
harvested blood stem cells have to be sent across countries.
Significance:
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This is the first
licensed therapy in the world based on the gene editing technology
Crispr-Cas9 that earned its innovators a Nobel Prize in 2020.