The U.S. Food and Drug Administration on Friday approved the first treatment in the United States to utilize the novel gene-editing technology Crispr.
Casgevy, a treatment developed using Crispr, is a treatment for sickle cell disease, a blood disorder that results from a genetic mutation that affects the protein in red blood cells responsible for delivering oxygen throughout the body. The mutation causes red blood cells to take on a “sickle” shape that can cause blood clots, low oxygen, and other side effects.
“Sickle cell disease is a rare, debilitating and life-threatening blood disorder with significant unmet need, and we are excited to advance the field especially for individuals whose lives have been severely disrupted by the disease by approving two cell-based gene therapies today,” Nicole Verdun, director of the Office of Therapeutic Products within the FDA’s Center for Biologics Evaluation and Research, said in a statement.
“Gene therapy holds the promise of delivering more targeted and effective treatments, especially for individuals with rare diseases where the current treatment options are limited,” she said.
Sickle cell disease most commonly affects black people, though Hispanic people also occasionally inherit it.
The disease affects the production of adult hemoglobin protein, which caused blood cells to take on the distinct shape. The human body has two genetic codes for the production of hemoglobin, a code for fetal hemoglobin and a code for adult hemoglobin. After birth, the production of fetal hemoglobin is turned off and adult hemoglobin production is started.
The treatment for sickle cell, Casgevy, uses CRISPR technology, first developed about a decade ago, to edit the genes responsible for the production of fetal hemoglobin to restart production.
“We’ve kind of been waiting for this ever since DNA was first discovered,” Lewis Hsu, chief medical officer for the Sickle Cell Disease Association of America, told CNN. “It’s been a long, long time coming.”
During trials, the drug was about 90% effective at stopping severe pain and organ damage caused by sickle cell disease for at least a year
“A total of 44 patients were treated with Casgevy. Of the 31 patients with sufficient follow-up time to be evaluable, 29 (93.5%) achieved this outcome. All treated patients achieved successful engraftment with no patients experiencing graft failure or graft rejection,” the FDA said.
The treatment has yet to be priced, though early estimates suggest it could cost millions. The Institute for Clinical and Economic Review, which advises insurance companies and drug makers on the fair price of therapies, said that a fair price for Casgevy would be between $1.35 million to $2.05 million per patient, according to The Wall Street Journal.
Also on Friday, the FDA approved another cell-based gene therapy for sickle cell, Lyfgenia. Lyfgenia modifies the patient’s cells to produce a substitute for the defective hemoglobin protein.