Regulators on Friday approved two gene therapies for sickle cell disease that doctors hope can cure the painful, inherited blood disorder that afflicts mostly Black people in the U.S.

The Food and Drug Administration said the one-time treatments can be used for patients 12 and older with severe forms of the disease. One, made by Vertex Pharmaceuticals and CRISPR Therapeutics, is the first approved therapy based on CRISPR, the gene editing tool that won its inventors the Nobel Prize in 2020. The other is made by Bluebird Bio and works differently.

Sickle cell disease is a rare, debilitating and life-threatening blood disorder with significant unmet need, the FDAs Dr. Nicole Verdun said in a statement announcing the approvals. We are excited to advance the field especially for individuals whose lives have been severely disrupted by the disease.

The two gene therapies are the first approved in the U.S. for sickle cell disease. The FDA has previously OKd 15 gene therapies for other conditions.