The Food and Drug Administration (FDA) has recently given a further approval to a CRISPR-based gene therapy developed collaboratively by Vertex Pharmaceuticals and CRISPR Therapeutics. The therapy, known as Casgevy, is now an officially approved treatment for beta thalassemia, a rare blood disorder.
The news of this approval was not surprising, given the therapy’s previous endorsement in December for its use in treating sickle cell disease. Interestingly, this approval came about two months ahead of schedule from its original target date of March 30. Moreover, in a first-time precedent, Casgevy gained its initial regulatory endorsement from the United Kingdom back in November and this embraced both sickle cell disease and beta thalassemia.
Beta Thalassemia is an inherited disorder originating from genetic mutations resulting in reduced levels of functional hemoglobin, leading to anemia. Blood transfusions, despite their risks and need for regularity, are a typical treatment path. A currently approved drug, Reblozyl, treats the accompanying anemia but is not curative, even though it reduces transfusion needs. Although stem cell transplants are potentially curative, they depend on having a matched donor. On the other hand, Casgevy presents a one-time treatment option for transfusion-dependent beta thalassemia patients aged 12 and above.
Now the second gene therapy FDA-approved for beta thalassemia following Zynteglo from Bluebird Bio, Casgevy’s commercial pricing for beta thalassemia is set at $2.2 million, equal to its price for sickle cell disease. Industry speculators suggest that, with a successful launch in other territories including Europe and Asia, sales could reach approximately $2.6 billion by 2028. However, availability is currently restricted to a selection of authorized treatment centers in the U.S. experienced in stem cell transplants, notably with more centers planned to offer Casgevy to eligible patients in the near future.
In addressing this recent FDA decision, Vertex CEO Reshma Kewalramani expressed great excitement at securing approval well ahead of the Prescription Drug User Fee Act (PDUFA) deadline, and emphasized their commitment to bringing Casgevy to those eligible patients who are desperately waiting for potentially curative treatment options.