The Swiss biotechnology company CRISPR Therapeutics has announced that it has used CRISPR to treat a patient with beta-thalassemia. This experiment was sponsored by Vertex Pharmaceuticals of Boston (see Americans finance an initial clinical trial using CRISPR/Cas9 in Europe).
People with beta-thalassemia inherit defective copies of the gene to synthesize haemoglobin, an essential molecule for transporting oxygen to body organs. However, everyone also inherits another copy of the gene to synthesize foetal haemoglobin, which is turned off in adulthood. To treat patients with beta-thalassemia, the strategy developed by CRISPR Therapeutics involves reactivating this copy of the foetal haemoglobin gene, called CTX001.
After harvesting stem cells from the patient’s bone marrow, they are modified using in vitro CRISPR and then reinjected into the patient’s bloodstream. “In theory”, a single treatment could be enough to cure the disease, “but it is too soon to know the result”. CRISPR Therapeutics is waiting to see how its first patient progresses before thinking about treating other people. Nevertheless, the company has already recruited a patient in the hope of curing his sickle cell disease using the same strategy.
For further reading:
- FDA remains cautious about CRISPR-based gene therapy for sickle cell disease
- Curing beta-thalassemia via CRISPR: has the time come to switch to human trials?
- This is not the first clinical trial using genome editing in adult males: Sangamo is running a clinical trial in the US on Hunter syndrome (see Genome editing: the Sangamo clinical trial has produced “disappointing” results), while in China, a team is using CRISPR to treat lung cancer (see CRISPR: the first patient treated in China).