Summary: FDA Approves World’s First Crispr Gene-Editing Drug for Sickle-Cell Disease

This summary assumes knowledge of CRISPR technology.

A new treatment called Casgevy, developed by Vertex Pharmeceuticals and CRISPR Therapeutics, was cleared on 8 December 2023 by the FDA for treatment of sickel-cell disease.

Sickle-cell disease affects 20 million people worldwide and is caused by a genetic mutation resulting in deformed and rigid haemoglobin being produced. They stuck in blood vessels, causing pain and infection. However, there are actually two types of haemoglobin. Fetal hemoglobin is produced while we are in the womb, is switched off at birth, and adult haemoglobin is produced after birth instead. CRISPR is used to turn off the gene disabling fetal haemoglobin production, which is unaffected by the mutation, so it can be produced in adults.

Casgevy works by gene editing cells in a lab instead of in the body. This reduces accidental modification of other genes, but requires days of painful high-dose chemotherapy for the modified genes to be inserted. It also has a high US$2.2 million price tag.

An alternative treatment for sickle-cell disease approved by the FDA on the same day is Lyfgenia. which genetically modifies patients’ cells to produce a haemoglobin substitute. It has a higher price tag of US$3.1 million.

Original article: FDA Approves World’s First Crispr Gene-Editing Drug for Sickle-Cell Disease