FDA Approves Vertex’s and CRISPR’s Casgevy to Treat Transfusion-Dependent Beta Thalassemia

Rare Daily Staff

The U.S. Food and Drug Administration has approved Vertex Pharmaceuticals and CRISPR Therapeutics’ gene-edited cell therapy, Casgevy, for the treatment of transfusion-dependent beta thalassemia in patients 12 years and older.

“On the heels of the historic FDA approval of Casgevy for sickle cell disease, it is exciting to now secure approval for TDT well ahead of the PDUFA date,” said Reshma Kewalramani, CEO and president of Vertex. “TDT patients deserve new, potentially curative treatment options, and we look forward to bringing CASGEVY to eligible patients who are waiting.”

Transfusion-Dependent Beta Thalassemia (TDT) is a serious, life-threatening genetic disease. TDT patients report health-related quality of life scores below the general population and the lifetime health care costs in the U.S. of managing TDT are estimated between $5 million and $5.7 million. TDT requires frequent blood transfusions and iron chelation therapy throughout a person’s life. Due to anemia, patients living with TDT may experience fatigue and shortness of breath, and infants may develop failure to thrive, jaundice and feeding problems. Complications of TDT can also include an enlarged spleen, liver and/or heart, misshapen bones, and delayed puberty. TDT requires lifelong treatment and significant use of health care resources, and ultimately results in reduced life expectancy, decreased quality of life and reduced lifetime earnings and productivity. In the U.S., the median age of death for patients living with TDT is 37 years. Stem cell transplant from a matched donor is a curative option but is only available to a small fraction of people living with TDT because of the lack of available donors.

Casgevy is a non-viral, ex vivo CRISPR/Cas9 gene-edited cell therapy for eligible patients with SCD or TDT, in which a patient’s own hematopoietic stem and progenitor cells are edited at the erythroid specific enhancer region of the BCL11A gene through a precise double-strand break. This edit results in the production of high levels of fetal hemoglobin (HbF; hemoglobin F) in red blood cells. HbF is the form of the oxygen-carrying hemoglobin that is naturally present during fetal development, which then switches to the adult form of hemoglobin after birth. Casgevy has been shown to reduce or eliminate VOCs for patients with SCD and transfusion requirements for patients with TDT.

Photo: Reshma Kewalramani, CEO and president of Vertex