CRISPR and another genetic strategy fix cell defects in two common blood disorders

It is a double milestone: new evidence that cures are possible for many people born with sickle cell disease and another serious blood disorder, beta-thalassemia, and a first for the genome editor CRISPR.

Today in The New England Journal of Medicine (NEJM) and tomorrow at the American Society of Hematology (ASH) meeting, teams report that two strategies for directly fixing malfunctioning blood cells have dramatically improved the health of a handful of people with these genetic diseases. One relies on CRISPR, marking the first inherited disease treated with the powerful tool created just 8 years ago. And both treatments are among a wave of genetic strategies poised to widely expand who can be freed of the two conditions. The only current cure, a bone marrow transplant, is risky, and appropriately matched donors are often scarce.

The novel genetic treatments have the same safety issues as bone marrow transplants for now, and may also be extraordinarily expensive, but there is hope those risks can be eliminated and the costs pared down. “This is an amazing time, and it’s exciting because it’s...