The US Food and Drug Administration (FDA) has approved the first ever cell-based gene therapy, a one-off treatment for patients with a rare genetic blood disease. The single treatment will cost US$2.8 million, making it the most expensive medicine in history.
Called Zynteglo, the gene therapy is designed to treat beta-thalassemia, a rare disease with patients often requiring life-long blood transfusions. The gene therapy is personalized to each patient.
Bone marrow stem cells are harvested from the patient and then genetically modified to insert working copies of a gene that can effectively produce functional red blood cells. The modified stem cells are then infused back into the patient, with the positive effects of the one-off treatment expected to last a lifetime.
Clinical trials have found 89% of patients become transfusion independent following the treatment but this kind of gene therapy is not without risk. Although no serious adverse events were detected in Zynteglo’s clinical trials, other trials testing similar kinds of gene therapies have reported cases of cancer.
In approving Zynteglo the FDA noted a potential risk for cancer and recommends monitoring patients for 15 years following treatment with the gene therapy. In June, when the therapy was evaluated by a panel of independent experts for the FDA, the cancer risks were noted but the benefits of the treatment were found to outweigh any potential harms.
The approval of Zynteglo is somewhat historic as it’s only the third gene therapy to reach the market in the United States. It is also the first cell-based gene therapy to ever be approved in the US, meaning it’s the first authorized therapy where stem cells are removed, genetically modified, and then returned to a patient.
But Zynteglo may become most notorious for setting a new benchmark in medicine costs. The company behind the medicine, bluebird bio, has set Zynteglo’s initial wholesale cost at $2.8 million, making it the most expensive medicine to ever reach the US market. The previous record was set by a gene therapy in 2019 called Zolgensma, with its one-off cost sitting around $2 million.
Addressing the high price of the treatment, bluebird bio has argued the cost must be considered as relative to the lifetime healthcare costs for patients with beta-thalassemia. The company said this single gene therapy treatment is essentially a cure that removes the need for decades of ongoing medical care.
“The lifetime cost of medical care for a patient with transfusion-dependent beta-thalassemia can reach up to $6.4 million in the U.S. and the average total health care cost per patient per year is 23 times higher than the general population,” the company explained in a statement. “bluebird estimates that there are approximately 1,300-1,500 individuals with transfusion-dependent beta-thalassemia in the U.S.”
The cost of one-time gene therapies has been a thorny topic for health insurers over the past few years. The nature of single-dose curative treatments means pharmaceutical companies are likely to set incredibly high prices as their only way to recoup the development costs that go into producing these therapies. However, insurance companies have unsurprisingly balked at the huge price tags.
Zolgensma’s $2 million price tag has been the source of extensive negotiation with health insurers over the past couple of years. Its manufacturer Novartis has tried to break its cost down into annual installments for insurers, spreading the price over three or four years.
Although bluebird bio has indicated it will reimburse insurers up to 80 percent of the treatment cost if Zynteglo fails in a given patient within two years, that still may not be enough some insurance companies.
Zynteglo was initially approved for use in the European Union back in 2019 but bluebird bio struggled to come to arrangements with health insurers over the treatment’s cost. The gene therapy was subsequently withdrawn from several markets in Europe after insurers refused to foot the multi-million-dollar bill.