The First CRISPR Therapy Approved for Sickle Cell Disease

Sickle cell disease is an inherited blood disorder that primarily affects people of African descent. It is caused by a genetic mutation that distorts red blood cells into a sickle or crescent shape. These misshapen cells can get stuck in blood vessels, blocking blood flow and oxygen delivery to tissues. This leads to periodic episodes of severe pain, organ damage, and other serious complications.

For over a century since sickle cell disease was first identified, patients had to rely on treatments that only managed the symptoms, not the underlying genetic cause. But now, a groundbreaking new gene-editing therapy offers the potential for a cure.

The therapy is called Casgevy, made by companies Vertex and CRISPR Therapeutics. It uses the CRISPR gene editing technology to modify cells taken from the patient's own blood. Specifically, it edits the cells to boost production of fetal hemoglobin - a form of hemoglobin made before birth that does not sickle.

Here's how the therapy works: First, some of the patient's blood stem cells are removed. Then CRISPR is used to edit a gene in those cells to turn on fetal hemoglobin production. The edited stem cells are infused back into the patient, where they can mature into new blood cells carrying the beneficial fetal hemoglobin instead of the sickle cell-causing adult hemoglobin.

In clinical trials, this approach was incredibly effective at reducing or eliminating sickle cell crises and complications in patients who received it. And because it edits stem cells, the effects can last for years from a single treatment.

The FDA recently approved Casgevy as the first CRISPR gene-editing therapy for any disease. While a major advance, there are still challenges - the multi-step process is complex and expensive at over $2 million per patient currently. But researchers are working to develop simpler gene editing therapies that could be more easily administered to sickle cell patients globally.

Overall, this CRISPR therapy marks an important milestone, using cutting-edge gene editing to directly correct the root genetic cause of sickle cell disease in a way never before possible. It provides hope for better treatments for the millions suffering from this debilitating disorder worldwide.