2 patients with blood disorders benefit from CRISPR treatment

Posted on: Thursday, November 21, 2019 By: KorchekStaff

The first two patients to receive CRISPR-based treatment for inherited blood disorders have benefited and experienced solely treatable side effects, showing promise for the experimental therapy, according to a Nov. 19 news release from CRISPR Therapeutics. 

The patients, one suffering sickle cell disease and the other beta thalassemia, participated in clinical trials and received treatment created by CRISPR Therapeutics and Vertex Pharmaceuticals. For less than a year, both patients haven't needed blood transfusions and have reduced disease symptoms, sparking the possibility that genome editing could one day offer a safe, lasting cure for both diseases. 

The trial treatment, called CTX001, uses CRISPR to reactivate a type of hemoglobin the body usually stops making soon after birth in hopes of the body then producing a healthy supply of it, according to STAT.

Nine months after treatment, the 20-year-old beta thalassemia patient's total hemoglobin reached near-normal levels, boosted by a significant increase in fetal hemoglobin.  

The beta thalassemia patient suffered from pneumonia, lowered white blood cells, and an enlarged, jaundiced liver as a result of the CRISPR treatment, Dr. Selim Corbacioglu of Germany's University of Regensburg, who treated the patient, told STAT. The side effects were expected and successfully treated.  

After receiving treatment in July, the sickle cell patient's total hemoglobin also reached normal levels, of which 47 percent was fetal hemoglobin, her physician Haydar Frangoul, MD, a hematology/oncology specialist of HCA Healthcare's Sarah Cannon Research Institute in Nashville, Tenn., told STAT. The patient suffered sepsis, gallstones and abdominal pain after treatment.

After the encouraging results from the first two patients, CRISPR and Vertex say 45 additional sickle cell and beta thalassemia patients will begin CTX001 treatment soon. 

Other companies and scientists are also pursuing treatment based on genome editing or gene therapy. More data is needed before comparisons between approaches can be made.