By Sola Ogundipe

The U.S. Food and Drug Administration (FDA) said the one-time treatments can be used for patients 12 and older with severe forms of the sickle cell disease.

One treatment is made by Vertex Pharmaceuticals and CRISPR Therapeutics. The other is made by Bluebird Bio.

A genetic change, or mutation, causes blood cells to become defective in people with sickle cell disease. The unhealthy blood cells result in blockages, called blood clots. The clots cause pain and damage to bones and organs in the human body.

The Vertex treatment is called Casgevy. Its goal is to help the body go back to producing healthy blood cells that are present at birth. It uses CRISPR, the gene editing tool, to knock out a gene in stem cells collected from the patient.

Bluebird’s treatment, called Lyfgenia, aims to add copies of a modified gene. The modified gene helps red blood cells to produce a protein that prevents or reverses unhealthy cells.

The two gene treatments are the first approved in the U.S. for sickle cell disease. Vertex is already approved in Britain and Bahrain.